Embed Size (px)
Citation preview
Fontys University of Applied Sciences
The Ceiling Effect: The 6MWT or “Glittreprotokollen” in COPD Patients with High Initial Functional Capacity
A retrospective observational study
Peter Johnson* *Corresponding Author, Department of Physiotherapy, English Stream 4A, Fontys University of Applied Sciences, Eindhoven, The Netherlands. Tel: 0031619335371. E-mail address: [email protected] 25.05.2012 Version 1.0 Supervisory teachers; Frank Vossen Ingrid Janssen
1
PREFACE
I spent my last clinical affiliation period before completing my bachelor’s degree at Glittreklinikken in
Norway. Glittreklinikken is a hospital specializing in pulmonary rehabilitation. It was conversations and
discussions with the health professionals at this hospital that inspired me with the idea and to further
carry out the research.
This paper presents one widely used test in pulmonary rehabilitation measuring functional capacity,
the 6MWT, and compares the outcomes to another test used at Glittreklinikken called
“Glittreprotokollen”.
“Glittreprotokollen” has been used for many years at Glittreklinikken and the health care professionals
using it have good experience with it. However, the test has not been published.
This paper is primarily addressed to health care professionals interested in or working with pulmonary
patients. It is the hope of the author that this research might spark further interest in
“Glittreprotokollen”, and that it might be a small first step for future research on the test.
2
SUMMARY
Objectives. To investigate whether “Glittreprotokollen” is more accurate in measuring the effect of
pulmonary rehabilitation (PR) than the 6 Minute Walk Test (6MWT) in Chronic Obstructive Pulmonary
Disease (COPD) patients with a high initial functional capacity, because of the ceiling effect related to
the 6MWT.
Design. A retrospective observational study reviewing and comparing the results of the 6MWT and
“Glittreprotokollen” pre- and post-an in-patient PR with the duration of four weeks.
Setting. Multidisciplinary PR mainly consisted of endurance and strength training, patient education,
mucous evacuation, breathing therapy, nutrition counseling, relaxation therapy, psychosocial
education and smoking cessation support.
Data collection. Data was collected from an electronic database at Glittreklinikken A/S. The data was
dated from a period between the 15th of November 2010 and the 9
th of March 2012.
Participants. Nineteen subjects, diagnosed with COPD according to the GOLD classification, were
included. Thirteen of the included subjects were diagnosed with moderate and six with severe COPD.
They had undertaken both a 6MWT and “Glittreprotokollen” pre- and post-PR. Subjects had
undertaken spirometry testing. Subjects with missing data in the electronic data files were excluded.
Results. Compared to the first week of PR, the average increase in 6 Minute Walk Distance (6MWD)
was 7.4m (SD 35.8m), or 1%. The average increase in power output in “Glittreprotokollen” was 33.2W
(SD 31.2W) or 39.8%.
Conclusion. Decisive conclusions in relation to the research question cannot be made at this point.
This study does however show a tendency in the direction of the 6MWT being unsuccessful in
detecting the change in functional capacity of subjects walking ≥ 550 m on their initial 6MWT after a
four week in-patient PR program. “Glittreprotokollen” on the other hand, did not show this limitation.
Keywords. COPD, pulmonary rehabilitation, 6MWT, “Glittreprotokollen”, ceiling effect.
3
Table of contents
INTRODUCTION ................................................................................................................................. 4
METHODS ........................................................................................................................................... 6
Setting. ............................................................................................................................................. 6
Study design. .................................................................................................................................... 6
Data collection. ................................................................................................................................. 7
Inclusion of subjects. ........................................................................................................................ 7
6MWT. .............................................................................................................................................. 7
“Glittreprotokollen”. ........................................................................................................................... 7
The modified Borg scale................................................................................................................... 8
Procedures. ...................................................................................................................................... 8
The statistical analysis of the data. .................................................................................................. 8
Ethics. ............................................................................................................................................... 9
RESULTS ........................................................................................................................................... 10
DISCUSSION ..................................................................................................................................... 14
CONCLUSION ................................................................................................................................... 17
ACKNOWLEDGEMENT .................................................................................................................... 18
RERERENCES .................................................................................................................................. 19
APPENDICES…………………………………………………………………………………………..……21
Appendix I: Project plan
Appendix II: Approval project plan
Appendix III: Agreement from Glittreklinikken regarding access to data
Appendix IV: Approval of project plan from Glittreklinikken
Appendix V: Mail from Regional Ethical Committee (REK) regarding ethical approval
Appendix VI: Protocol 6MWT
Appendix VII: Protocol Glittreprotokollen
Appendix VIII: Protocol 1 RM leg strength
Appendix IX: Protocol strength training
Appendix X: The modified Borg scale
4
INTRODUCTION
Chronic Obstructive Pulmonary Disease (COPD) is a disease with widely spread clinical
presentations, the shared abnormality being airflow limitations. It is defined as “a preventable and
treatable disease with some significant extra pulmonary effects that may contribute to the severity in
individual patients. Its pulmonary component is characterized by airflow limitation that is not fully
reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory
response of the lung to noxious particles or gases” [1]. According to the World Health Organization
(WHO), COPD was by 2002 the fifth leading cause of mortality worldwide [2]. WHO-estimates predict
COPD to rank as number three in leading cause of chronic mortality in 2030 [2].
According to the Global initiative for Chronic Obstructive Lung Disease (GOLD), effective management
of COPD consists of four different components: “(1) assess and monitor disease, (2) reduce risk
factors, (3) manage stable COPD, and (4) manage exacerbations” [1]. Pulmonary rehabilitation (PR)
takes aim at these factors, and research leaves little doubt that PR can considerably limit the burden
of this disease [3, 4, 5]. This is achieved by reducing symptoms related to COPD such as dyspnea and
improving the functional capacity of these patients [4, 5].
As functional capacity is dependent on several systems afflicted by COPD, tests describing the
functional capacity of patients with COPD are a cornerstone in determining the effect of PR [6, 7, 8, 9].
The 6 Minute Walk Test (6MWT) is one of the most widely used tests for this purpose in PR today [7,
8, 10, 11, 12, 13]. It is easy to administer and it demands little and inexpensive equipment.
There are however certain limitations to the 6MWT. Two prominent limitations related to the 6MWT
occur when the subject being tested either has a very low or a very high baseline functional capacity.
These limitations are often referred to as floor or ceiling effects. Frost et al. (2005) describes the
ceiling and floor effect as follows; “All tests suffer from “floors” and “ceilings,” i.e., a point at which the
performance is so good or so bad that further significant (clinically and statistically) deterioration or
improvement becomes hard to detect” [14].
The floor effect of the 6MWT has been extensively researched in COPD patients [7, 10]. Schünemann
et al. (2005) defined the minimal important difference (MID) as “…the smallest difference in score in
the outcome of interest that informed patients or informed proxies perceive as important, either
beneficial or harmful, and which would lead the patient or clinician to consider a change in the
management” [15]. Put simply, the “MID is used to interpret whether the observed change is important
from the patient's or clinician's perspective” [16]. The original MID of the 6 Minute Walk Distance
(6MWD) was set by Redelmeier et al. to 54 m in 1997. More recently, Puhan et al. opted for a change
of the MID from the original 54 m to 35 m and later to 24 m [7, 10, 17]. This was however in patients
with respectively moderate to severe, and severe COPD.
On the opposite side of the specter, there is a well-known ceiling effect related to the 6MWT [14, 18,
19]. In relation to the 6MWT, the ceiling effect is attributed to the combination of the 6MWT limiting the
subject to walk and the physical limitation of how fast it is possible to walk [18, 19]. Using the 6MWT to
determine the effect of PR in subjects with a high initial functional capacity might give the impression
of the PR being without results. This is because in contrast to the MID being lowered for patients with
moderate to severe and severe COPD, there are no such regulations for patients with an initial high
functional capacity.
Glittreklinikken is a hospital specialized for pulmonary rehabilitation located in Norway. At this hospital,
“Glittreprotokollen” is used to measure the effects of PR as one of its applications. “Glittreprotokollen”
is a modified version of the Bruce treadmill test [20], which has been adapted for use with pulmonary
patients. The test is performed to the patient’s symptoms limit maximum rather than a specified time.
Additionally, it does not limit the patients to walk.
5
Therefore the purpose of this study is to investigate whether “Glittreprotokollen” is more accurate in
measuring the effect of PR than the 6MWT in COPD patients with a high initial functional capacity,
because of the ceiling effect related to the 6MWT.
6
METHODS
Setting. Before patients were admitted to Glittreklinikken for the 4 week in-patient PR, an application
had to be submitted by either their general practitioner (GP) or by a hospital doctor. When the
application was approved, the patients and their respective GPs received a letter confirming the
approval of the application and expected duration before admittance. Patients were contacted by
phone to map smoking habits. At least 4 weeks before admittance, patients received a letter
containing information stating date of admission, a brochure regarding the stay and information
regarding communicable diseases. Patients were then placed in one of six multidisciplinary teams
where rehabilitation was organized according to the guidelines of the ATS/ERS [4, 5].
Shortly after initiating their stay at Glittreklinikken, an anamnesis was carried out by a hospital doctor
as well as a conversation with the nursing service regarding the patients’ goals for the coming four
weeks. Patients were then tested for baseline strength and endurance by a physical therapist and
received an individualized training program. Strength was assessed on a leg press machine by a 1
repetition maximum (1RM) test for leg strength (Appendix VIII: Protocol 1RM leg strength, Norwegian)
and endurance was tested by utilizing “Glittreprotokollen” (Appendix VII: Protocol Glittreprotokollen,
Norwegian). The individualized training program consisted of a strength program mainly focusing on
big muscle groups (Appendix IX: Protocol Strength training, Norwegian) and an endurance program on
a treadmill. The endurance program was based on the results of the initial “Glittreprotokollen” test and
was in most cases based on the principles of interval training.
Routine tests were carried out such as chest x-rays, spirometry testing, body-box and blood gasses as
well as the 6MWT (Appendix VI: Protocol 6MWT, Norwegian).
The first of in total three multidisciplinary team meetings were held within the first week of PR where
the rehabilitation plan for the patient was discussed and set up.
During the PR, patients received a weekly scheduled meeting with their team doctor. The hospital
doctors also offered the patients group education regarding themes such as COPD, asthma, allergy
and medicines. When relevant, patients received smoking cessation support as well as group
education by the nursing service regarding the use of medicine, inhalation technique and use of
supplementary oxygen. Furthermore, patients were offered conversation groups with topics such as
how to cope with exacerbations, how to live with a chronic pulmonary disease as well as nutritional
advice. Patients received individual follow up by a nurse during the full duration of the stay.
In addition to their individualized training programs, patients were offered morning gymnastics, Nordic
walking, training in a swimming pool and occasional spinning and climbing groups by the physical
therapists. The physical therapists also offered patient education in form of breathing techniques,
mucous evacuation, training theory and relaxation therapy.
Progression of the patients’ individualized training program was provided during weekly meetings with
the physical therapist. Patients also received advice on how to continue training post-PR and
assistance in locating a physical therapist in their local environment if needed.
In addition to this, occupational therapy was offered focusing on ADL-activities as well as psycho-
social education by psychologists, nutritional advice by dietitians and social economic assistance by
social workers.
Study design. The study design was that of a retrospective observational study reviewing and
comparing the results of the 6MWT and “Glittreprotokollen” pre- and post-an in-patient PR with the
duration of four weeks.
7
Data collection. Data was collected from an electronic database at Glittreklinikken A/S. The data was
dated from a period between the 15th of November 2010 and the 9
th of March 2012. Subject
characteristics, 6MWD of the 6MWT and maximum velocity and inclination of “Glittreprotokollen” were
recorded. Data was printed, ID labeled and accumulated in a folder which was stored in a secure
location at Glittreklinikken. Data was imported into an excel spread sheet and later in MedCalc
statistical software. All data was fully anonymous.
Inclusion of subjects. All subjects were diagnosed with COPD according to the GOLD classification.
They had undertaken both a 6MWT and “Glittreprotokollen” pre- and post-PR. During the baseline
6MWT, subjects had to walk a distance of ≥ 550 m on minimum one of the two initial trials. During
“Glittreprotokollen”, they had to walk on protocol 3 or 4 (table 1). Subjects had undertaken spirometry
testing. Subjects with missing data in the electronic data files were excluded. Subjects had undergone
a four week in-patient PR program in accordance to evidence based guidelines [4, 5].
6MWT. The 6 Minute Walk Test followed standard procedure and recommendations from the
American Thoracic Society [21]. The test was performed in a corridor with 30m markers. Standard
instruction was given. Standard encouragement phrases were used every minute. The initial test was
performed twice, with a pause of at least 30 min, to account for a learning effect [21, 22]. The test was
performed again at the end of the PR period. 6MWD was noted as well as saturation (SpO2) and the
patients subjective grading of dyspnea according to the modified Borg scale (also known as the Borg
CR-10 scale, ranging from 0 – 10) before and after the completion of the test [23].
“Glittreprotokollen”. “Glittreprotokollen” is a modified version of the Bruce treadmill test which has
been adapted to pulmonary patients [20]. It has a lower initial speed and earlier inclination than the
original test. The test follows a stepwise progression, with increasing load every 2nd
minute based on
the set protocol.
The test is performed on a treadmill. Patients are instructed to perform the test until the patients
symptoms limit maximum rated by the modified Borg scale. Pulse oximetry and heart rhythm is
continuously monitored during the test. The subjects are asked to rate their perceived exertion of
dyspnea and legs during the last half minute of each exercise step using the modified Borg scale [23].
There are four set protocols ranging from a low (protocol 1), to a high (protocol 4) work rate (WR). The
four protocols increase similarly during each exercise step, but primarily differ in initial walking speed.
Patients in this particular study walked on protocol 3 or 4 (table 1). As the test starts, the treadmill is
set to a speed which the patient experiences as his or her habitual walking speed in accordance to
one of the four preset protocols.
The test is designed with the intention to run for about 8 - 12 minutes and never exceeds 30 minutes.
When patient’s symptoms limit maximum, rated by the modified Borg scale, the inclination was set to
0% and speed was returned to the initial setting, according to the chosen protocol. The last
measurements were done at the first and the third minute at initial WR.
Protocol 3 started with an initial speed of 3.6 km/h and protocol 4 on 4.8 km/h. The speed was then
increased by 0.6 km/h every 2nd
minute. The speed was increased until 5.4 km/h was reached. For
further increases in workload, the inclination was initially increased by 4%, and then by 2% every 2nd
minute. In protocol 3, maximum inclination was reached at 14%, in protocol 4 maximum inclination
was reached at 8%. For further increases, the speed was increased by 0.6 km/h every 2nd
minute until
a maximum of 8.4 km/h in protocol 3 and 11.4 km/h in protocol 4 (table 1).
The same protocol was used at pre- and post-testing. Post-testing was preferably performed at the
same time of day to minimize intraday variability in physical functioning of the subjects [21].
8
Table 1: Work load during “Glittreprotokollen”
Protocol 3 Protocol 4
Min Km/h Inclination % Km/h Inclination % 0 0 0 2 3.6 4.8 4 4.2 5.4 4 6 4.8 5.4 6 8 5.4 5.4 8
10 5.4 4 5.4 8 12 5.4 6 6 8 14 5.4 8 6.6 8 16 5.4 10 7.2 8 18 5.4 12 7.8 8 20 5.4 14 8.4 8 22 6 14 9 8 24 6.6 14 9.6 8 26 7.2 14 10.2 8 28 7.8 14 10.8 8 30 8.4 14 11.4 8
1 3.6 4.8 3 3.6 4.8
The modified Borg scale. A parameter in addition to the primary outcomes typically measured in
PR-candidates in functional tests such as the 6MWT and “Glittreprotokollen” is dyspnea [5, 24].
Dyspnea is often measured by utilizing the modified Borg scale (Appendix X: The modified Borg Scale,
Norwegian) [4]. The Borg scale has been recommended to measure the effect of PR in relation to the
patient’s subjective grading of dyspnea and exertion of legs in addition to estimation of training
intensity [5, 24]. The MID of the Borg scale has been investigated and set to a change in one unit for
dyspnea [25].
Procedures. Of the two initial 6MWT, the one which gave the highest 6MWD was used as the
baseline measurement. During “Glittreprotokollen”, subjects had to walk on a specific exercise step for
at least 30 seconds in order for it to be registered as the peak exercise step.
As “Glittreprotokollen” increases in WR by both increasing in velocity and inclination, the Jaeger
formula was used to produce one primary outcome [26]. This was done to be able to compare the
primary outcomes of the 6MWT and “Glittreprotokollen”. The primary outcome of “Glittreprotokollen”
was calculated to Watts (W) based on weight, peak speed and inclination of the specific subject [26].
The Jaeger formula is divided in to two separate formulas reflecting the increase of WR related to
running compared to that of walking. In this study, this limit was set to 8 km/h. Difference in weight of
the subjects from baseline to the end of the PR period was taken into account when this was
mentioned in the collected data.
Outcomes of the tests were compared pre- and post-PR. For the 6MWT, outcomes were compared
pre- and post-testing. For “Glittreprotokollen”, outcomes were compared pre- and post-testing at ISO
time and at peak time.
The statistical analysis of the data. Data was analyzed and compared using MedCalc statistical
software (software version 12.1.3.0). Descriptive statistics (age, weight, height, BMI, FEV1 %
predicted and FEV1/FVC) were extracted from the spirometry datasheets and calculated as summary
statistics including mean, standard deviation (SD), minimum and maximum values. The data was
presented in tables and graphs made in Microsoft Excel (2010).
9
The change in 6MWD was calculated as percentual change.
The percentual change in WR of “Glittreprotokollen” and the percentual change in 6MWD were
compared and presented in graphs. This was in order to see whether or not these tests would give
different impressions of the physical function after the four week in-patient PR.
Ethics. An application for ethical approval was sent to Regional Ethical Committee (REK sør-øst), on
which it was made clear that Fontys University of Applied Sciences and eventual other relevant
institutions (Glittreklinikken) should be responsible for ensuring the ethical standard of the project
(Appendix V: Mail from REK regarding ethical approval, Norwegian). The ethical standard was
approved together with the signed consent of the project plan by both parties (Appendix II: Approval
project plan, Appendix IV Approval project plan form Glittreklinikken, Norwegian).
10
RESULTS
All eligible subjects meeting the inclusion criteria were included in the study. Of 372 patient files, 34
subjects completed both tests according to the inclusion criteria and had no missing data in the
electronic database. Of these 34 subjects, 14 were excluded due to not being diagnosed with COPD
according to the GOLD classification and an additional one subject did not complete post-PR 6MWT.
This resulted in 19 participants. Thirteen of the subjects were diagnosed with moderate and six with
severe COPD (table 2).
Table 2: Baseline characteristics of participants (n = 19)
Mean SD Min Max
Age 60.6 7.09 49.0 82.0 Height (m) 1.7 0.06 1.56 1.85 Weight (Kg) 68.7 12.9 43.1 85.8 BMI 23.6 3.9 17.8 30.4 FEV1 (% predicted) 60.4 13.2 34.0 85.0 FEV1/FVC 54.3 9.6 34.4 67.5 6MWD (m) 604.5 41.7 550 690 Power output (W) 118.6 43.5 33 206 Protocol walked during “Glittreprotokollen”, No. 3 12 4 7 COPD severity according to GOLD standards, No. II 13 III 6 Male/female ratio Male Female 7 12
Compared to the first week of PR, the average increase in 6MWD was 7.4m (SD 35.8m), or 1% (table
3). As subjects are asked to walk as far as possible during the test, it was expected that the Borg
score would not change notably during pre- and post-PR testing. This fact is reflected in the results,
which showed a mean change of -0.1 (SD 0.7) points before the test was performed and 0 (SD 2.4)
points after the test was performed (table 3).
Table 3: Changes in perceived rating of exertion of dyspnea and legs and 6MWD pre- and post-PR
(n = 19)
6MWT Mean SD Min Max
Changes in primary outcome 6MWD pre (m) 604.5 41.7 550 690 6MWD post (m) 611.8 56.5 540 740 6MWD change (m) 7.4 35.8 -80 60 6MWD change (%) 1.0 6.0 -14.0 9.0
Changes in Borg CR-10 scale (dyspnea) Pre-PR results Borg pre (week 1) 0.6 0.8 0 2.5 Borg pre (week 4) 0.8 1.1 0 4 Borg change -0.1 0.7 -2 0.5 Post-PR results Borg post (week 1) 4.6 2.1 2 10 Borg post (week 4) 4.6 2.2 2 10 Borg change 0 2.4 -3.5 8
11
Table 4 shows a sub-analysis of the 6MWT. The results presented are divided into subjects who showed an increase in 6MWD and subjects who did not show an increase in 6MWD. The Mean change in the 6MWT for subjects increasing 6MWD was 26.2m (SD 19.9m), or 4% (SD 2.5), and the mean change for subjects who did not increase 6MWD was -33.3m (SD 30.8), or 5.9% (SD 5.3).
Table 4: Sub-analysis of the 6MWD pre- and post-PR
Mean SD Minimum Maximum
6MWD showing increase post-PR (n = 13) 6MWD pre 608.5 41.7 550 690 6MWD post 634.6 52.9 570 740 6MWD change 26.2 17.9 5 60 6MWD change(%) 4.0 2.5 0.01 8.5
6MWD not showing increase post-PR (n = 6) 6MWD pre 595.8 44.3 560 660 6MWD post 562.5 22.3 540 600 6MWD change -33.3 30.8 -80 0 6MWD change(%) 5.9 5.3 -14 0
The average increase in power output in “Glittreprotokollen” was 33.2W (SD 31.2W) or 39.8% (table
5). The increase of peak power output in “Glittreprotokollen” was paralleled by decreased scores on
the modified Borg scale for perceived rating of exertion of dyspnea and legs at ISO time (table 5).
Table 5: Changes in perceived rating of exertion of dyspnea and legs at ISO time measured by the
modified Borg scale and work rate (W) pre- and post-PR (n = 19)
Glittreprotokollen Mean SD Min Max
Changes in primary outcome Watt pre (W) 118.6 43.5 33.0 206.0 Watt post (W) 151.7 45.5 66.0 240.0 Watt change (W) 33.2 31.2 -18.0 98.0 Watt change (%) 39.8 53.8 -17.0 178.0
Changes in Borg CR-10 scale Dyspnea (ISO) Borg pre 7 1.3 5 10 Borg post 5.4 1.5 3 9 Borg change 1.5 2.1 -2 7 Legs (ISO) Borg pre 4.7 2.4 0 9 Borg post 3.2 1.9 0 6 Borg change 1.5 2.4 -3 5
The changes in the 6MWD pre- and post-PR are graphically presented in figure 1. Results show small
variations in pre- and post-6MWD. Out of the 19 subjects, only one surpassed the MID (54m) with a
change in 6MWD of 60 m (figure 1). Further, it can be seen that five subjects decreased their 6MWD
on post-testing (figure 1).
12
Figure 1: The change in 6MWD pre- (blue bars) and post- (red bars) PR.
The changes in power output in “Glittreprotokollen” pre- and post-PR is graphically presented in figure
2. Results here show bigger variations in change pre- and post-PR than the results of the 6MWT. One
subject shows a decrease in WR post-PR (figure 2). The subject who showed a decrease in WR
(figure 2), also showed an increase in 6MWD (figure 1).
Figure 2: The change in WR pre- (blue bars) and post- (red bars) PR
Comparing the change of the primary outcomes of 6MWT and “Glittreprotokollen” shows large
variation in results (figure 3). While “Glittreprotokollen” demonstrates several peaks in percentual
change in WR, percentual change of 6MWD has a more even distribution.
13
Figure 3: Change in percent of 6MWT (blue line) and “Glittreprotokollen” (red line) pre- and post-PR.
14
DISCUSSION
The purpose of this study was to determine whether “Glittreprotokollen” is more accurate in measuring
the effect of PR than the 6MWT in COPD patients with a high initial functional capacity, because of the
ceiling effect related to the 6MWT. Before presenting a final conclusion, there are several points of
discussion worth mentioning.
There exists, to the author’s knowledge, no exact limit from where the ceiling effect will be
demonstrable in COPD patients. This is because such a limit depends on several factors such as
habitual walking velocity and leg length. However 550 m was chosen as a compromise between
including enough subjects and that it was believed that this level was close to where a subject would
have to change gait pattern from walking to running.
It would have been beneficial to have a higher number of subjects participating in the study. This was
limited by several factors. Perhaps the greatest limitation in this respect was the high demands of the
functional capacity of the subjects. However this requirement was necessary to demonstrate the
ceiling effect related to the 6MWT. Furthermore, only subjects being tested on protocol 3 or 4 during
“Glittreprotokollen” were included. This was chosen due to the time limitation of the study. Including
subjects who were tested on protocol 1 and 2 might have resulted in a larger study population,
however it is the opinion of the author that most subjects being tested on protocol 1 and 2 do not have
the functional capacity of being able to achieve a 6MWD ≥ 550 m. The reason for this is that
“Glittreprotokollen” is designed with the intention to last about 8 - 12 minutes on the initial test.
Protocol 2 reaches a speed of 5.4 km/h at 12 minutes and protocol 1 at 16 minutes (at that point, both
protocols are at 0% inclination). The velocity of this exercise step would be equivalent to walking 540
m during the 6MWT.
It can also be said that the criteria for men and women for initial 6MWD should differ. This is because
in general, men have a greater 6MWD than do women [22, 27, 28]. If the criteria for the 6MWD would
have been lowered for women, this probably would have resulted in a larger study population. It is at
this point unclear how this would have influenced the results. If, on the other hand, the criteria for the
6MWD would have been increased for men, this would have resulted in a lower study population
which would have been unbeneficial.
It might also be a point of interest that all subjects received an endurance program on a treadmill. This
endurance program was based on the results of the initial test of “Glittreprotokollen”. Subjects were
thus trained at performing on a treadmill. This might have worked in favor of “Glittreprotokollen”, as the
6MWT does not take place on a treadmill whereas “Glittreprotokollen” does. Subjects were however
encouraged to train endurance exercises according to their own preferences. This might have included
using a stationary bike, utilizing the stairs or performing outdoor Nordic walking.
The 6MWT is an internally paced test, which always takes place on a level surface. “Glittreprotokollen”
on the other hand is externally paced and increases in WR are achieved by a stepwise shift in both
velocity and in inclination. Furthermore, the 6MWT follows a continuous protocol, while
“Glittreprotokollen” follows a step wise protocol. A direct comparison of the two tests is for these
reasons not completely accurate. As “Glittreprotokollen” increases in two separate parameters, using
the distance change in “Glittreprotokollen” as the primary outcome would not be appropriate. Use of
the Jaeger formula was therefore necessary to merge the two parameters to one. There exist formulas
to calculate WR on a level surface which might have been appropriate to use in conjunction with the
6MWT. This was however not done, as it might raise additional questions to the accurateness of the
formulas used. Furthermore, WR depends on many aspects, among other if the subject is walking or
running. As the study was retrospective, the patients were not observed by the author during testing. A
set limit for walking/running was therefore used (8 km/h).
15
Keeping in mind that a change of 1 unit in the modified Borg Scale is considered to be the MID, there
are some points worth mentioning. The positive results of the primary outcome in “Glittreprotokollen”
were further underscored by the outcomes of the Borg scale at ISO-time, which improved by the mean
of 1.5 units for both perceived rating of exertion of dyspnea (SD 2.1 units) and legs (SD 2.4 units). This
means that, not only were the patients able to achieve a higher peak exercise step, but they also
found the WR at ISO-time less strenuous than on pre-testing. In other words, their exercise tolerance
had increased. Had the 6MWT showed similar results, one might say that the test was successful in
presenting clinical important differences post-PR even though there were no significant changes in the
6MWD. However the mean change of Borg score during the 6MWT post-PR testing was that of 0 units
(SD 2.4 units).
Of the 19 subjects included in the study, five subjects decreased their 6MWD on post-testing. In the
case of “Glittreprotokollen”, only one subject had a decrease (of 18 W) in WR. There are two likely
reasons for this gap. The reason for patients generally not decreasing in “Glittreprotokollen” might be
related to a training effect, i.e. subjects getting used to training on a treadmill. This would further aid in
explaining how subjects were able to increase as much as is seen in this study (up to 178 %). The
second probable reason for more patients showing a decrease in functional capacity in the 6MWT
after PR compared to “Glittreprotokollen”, is related to the ceiling effect of the 6MWT. This claim is
further supported by the sub-analysis of the 6MWT. The no-increase group showed an average
decrease of 33.3m (SD 30.8) and the increase group showed an average increase of 26.2 m (SD
17.9). Even when separating the subjects into an increase and a no-increase group, the MID is still not
reached.
Interestingly enough, the subject who showed a decrease in WR in “Glittreprotokollen”, showed an
increase in 6MWD of 20 m. Comparing the Borg scores during “Glittreprotokollen” of the same subject,
revealed that the perceived rating of dyspnea at ISO time was 2 units higher during post-testing (7
units during the initial test, and 9 units during the post-test). This might be attributable to a number of
factors. Perhaps the test was not performed at the same time of day affecting the intraday variability in
physical functioning, or maybe the patient had forgotten to take his/her medication related to improving
ventilation. This was however not noted in the test sheets and at this point it can only be speculated in
the actual cause of this abnormality. Another possible explanation might be related to the
psychometric properties of “Glittreprotokollen”.
Irregardless of these discussion points, it seems clear from the results that the 6MWT and
“Glittreprotokollen” gave different impressions of the gain in functional capacity pre- and post-PR.
Whereas the 6MWT showed a mean change in 6MWD of merely 1% (7.4m) (SD 35.8m),
“Glittreprotokollen” gave a mean change of 39.8% (33.2W) (SD 31.2W). These results clearly
demonstrate that the ceiling effect was reached during the 6MWT whereas this was not the case with
“Glittreprotokollen”.
Looking at the strengths of this study and the relevance in clinical practice, there are some points
worth mentioning. If the results in relation to the ceiling effect of the 6MWT presented in this study are
further investigated and confirmed in future studies with larger populations, this might change the
application of the 6MWT. In that respect, one possible outcome proposed, is to investigate whether the
6MWT should be performed in a population who one can expect will not reach the current MID for the
6MWT at all. In other words, it should be investigated if there should be a certain limit on the initial
6MWD where one would not carry out post-testing. Another possible outcome might be to further
develop the MID taking the ceiling effect into account in specific populations such as COPD patients
with an initial high functional capacity.
What makes this particular study interesting is that it compares a well-known test for physical capacity,
to a test which previously has not been investigated. From the results obtained in this study, it seems
like the weaknesses of the 6MWT are not present in “Glittreprotokollen”, and thus that
“Glittreprotokollen” might be a more accurate measurement tool in the specified patient group.
16
However, if “Glittreprotokollen” is to be used as a new measurement tool in PR, it is proposed that the
accurateness of the test is further investigated.
To further investigate the accurateness of “Glittreprotokollen” and its psychometric properties, it is
proposed to compare the results of “Glittreprotokollen” to that of a Cardiopulmonary Exercise Test
(CPET). This would further help determining the validity and reliability of the outcomes, as the CPET
has been shown to hold a high level of validity and reliability. Future research describing a new MID in
relation to the ceiling effect of the 6MWT in the same manner as the MID has been changed for
moderate to severe and severe COPD patients is also proposed.
17
CONCLUSION
Decisive conclusions in relation to the research question cannot be made at this point. This is due to
the design of the study being a direct comparison of a continuous (6MWT) and a stepwise
(“Glittreprotokollen”) protocol. This study does however show a tendency in the direction of the 6MWT
being unsuccessful in detecting the change in functional capacity of subjects walking ≥ 550 m on their
initial 6MWT after a four week in-patient PR program. “Glittreprotokollen” on the other hand, did not
show this limitation as subjects were able to increase their primary outcome (work rate) with up to
178% (with a mean increase of 39.8%) on post-PR testing. Further research is proposed to study the
psychometric properties of “Glittreprotokollen” in order to determine the validity and reliability of
“Glittreprotokollen”.
18
ACKNOWLEDGEMENT
My sincere thanks go to Frank Vossen and Ingrid Janssen, acting supervisors for the project, for their
comments on the manuscript. I thank the people representing FOU at Glittreklinkken A/S for allowing
access to the much needed data of which the project would not be possible to complete without. I
thank Anne Edvardsen, Anita Grongstad, Ulla Dagrunn Pedersen and Siri Skumlien at Glittreklinikken
for valuable input during several discussions regarding the project. This research would not have
reached its present form without their invaluable help. I thank Tjarco Koppenaal for his support; I thank
Marte Nystad Glad, Kari Saksenvik, Vasileios Polatoglou and Ole Jonas Liereng for comments during
peer reviewing. I thank Thomas John Johnson for his kind contribution in linguistically checking this
manuscript.
19
RERERENCES
[1]: Rabe KF, Hurd S, Anzueto A, Barnes PJ, Buist SA, Calverley P et al. Global strategy for the
diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive
summary. Am J. Respir Crit Care Med. 2007;176:532-55.
[2]: Chronic obstructive pulmonary disease (COPD) [Internet]. The World Health Organization; 2012.
Accessed: 29/04/2012. Available at http://www.who.int/respiratory/copd/en/
[3]: Lacasse Y, Goldstein R, Lasserson TJ, Martin S. Pulmonary rehabilitation for chronic obstructive
pulmonary disease. The Cochrane Library. 2009; 3.
[4]: Nici L, Donner C, Wouters E, Zuwallack R, Ambrosino N, Bourbeau J et al. American Thoracic
Society/European Respiratory Society Statement on Pulmonary Rehabilitation. 2005.
[5]: Nici L, Donner C, Wouters E, Zuwallack R, Ambrosino N, Bourbeau J et al. American Thoracic
Society/European Respiratory Society Statement on Pulmonary Rehabilitation. Am J Respir Crit Care
Med. 2006; 173: 1390-413.
[6]: Whipp BJ, Ward SA. Quantifying interventionrelated improvements in exercise tolerance. Eur
Respir J. 2009; 33: 1254-60.
[7]: Puhan MA, Mador MJ, Held U, Goldstein R, Guyatt GH, Schünemann HJ. Interpretation of
treatment changes in 6-minute walk distance in-patients with COPD. WUR Respir J. 2008; 32: 637-43.
[8]: Sutherland ER, Make BJ. Maximum Exercise as an Outcome in COPD: Minimal Clinically
Important Difference. COPD: Journal of Chronic Obstructive Pulmonary Disease. 2005, 2:137-41.
[9]: Kocks JWH, Asijee GM, Tsiligianni IG, Kerstjens HAM, Molen T: Functional status measurement in
COPD: a review of available methods and their feasibility in primary care. Prim Care Respir J. 2011;
20(3): 269-75.
[10]: Puhan MA, Chandra D, Mosenifar Z, Ries A, Make B, Hansel NN, Wise RA, Scuriba F. The
minimal important difference of exercise tests in severe COPD. Eur Respir J. 2011; 37: 784-90.
[11]: Li AM, Yin J, Yu CCW, Tsang T, So HK, Wong E et al. The six-minute walk test in healthy
children: reliability and validity. Eur Respir J. 2005; 25: 1057-60.
[12]: Jenkins SC. 6-Minute walk test in-patients with COPD: clinical applications in pulmonary
rehabilitation. Physiotherapy. 2007; 93: 175-82.
[13]: Wise RA, Brown CD. Minimal clinically important differences in the six-minute walk test and
incremental shuttle walking test. COPD. 2005; 2: 125-29.
[14]: Frost AE, Langleben D, Oudiz R, Hill N, Horn E, McLaughlin V. The 6-min walk test (6MWT) as
an efficacy endpoint in pulmonary arterial hypertension clinical trials: Demonstration of a ceiling effect.
Vascular Pharmacology. 2005 43: 36 - 9.
[15]: Schünemann HJ, Guyatt GH. Commentary – Goodbye M(C)ID! Hello MID, where do you come
from? 2005. HSR 40:2: 593 - 7.
[16]: Revicki DA, Cella D, Hays RD, Sloan JA, Lenderking WR, Aaronson NK. Responsiveness and
minimal important difference for patient reported outcomes. Health Qual Life Outcomes. 2006; 4: 70.
20
[17]: Redelmeier DA, Bayoumi AM, Goldstein RS, Guyatt GH. Interpreting small differences in
functional status: the six minute walk test in chronic lung disease patients. Am J Respir Crit Care Med.
1997; 155: 1278-82.
[18]: Al-Ghimlas F, Todd DC. Predictors of Success in Pulmonary Rehabilitation for Patients With
Interstitial Lung Disease. Chest. 2009: 136; 1183-84.
[19]: Pepin V, Brodeur J, Lacasse Y, Milot J, LeBlanc P, Whittom F, Maltais F. Six-minute walking
versus shuttle walking: responsiveness to bronchodilation in chronic obstructive pulmonary disease.
Thorax. 2007; 62:291-98.
[20]: Grendahl H, Platou ES. Arbeidsbelastning in: Kardiologiske metoder. Oslo: Hjerte Forum Organ
for Norsk Cardiologisk Selskap; 1997. p.78-9, 85. Norwegian.
[21]: ATS Statement: Guidelines for the Six-Minute Walk Test. Am J Respir Care Med. 2002; Vol 166:
111-7.
[22]: Gibbons WJ, Fruchter N, Sloan S, Levy RD. Reference values for a multiple repetition 6-Minute
Walk Test in healthy adults older than 20 years. Journal of Cardiopulmonary Rehabilitation. 2001; 21
issue 2: 87 – 93.
[23]: Christensen CC, Ryg MS, Edvardsen A, Skjønsberg OH. Relationship between exercise
desaturation and pulmonary haemodynamics in COPD patients. Eur Respir J. 2004; 24: 580-6.
[24]: Hastrup J, Hove L. Den rigtige Borg-skala til vurdering af dyspnø; Fysioterapeuten. 2008; 10.
Danish.
[25]: Ries AL. Minimally clinically important difference for the UCSD Shortness of Breath
Questionnaire, Borg Scale, and Visual Analog Scale. COPD. 2005; 2(1): 105-10.
[26]: Eschenbacher H. Can the exercise on treadmill be indicated in Watt? Viasys Healthcare,
respiratory technologies. 2009.
[27]: Enright PL, Sherrill DL. Reference equations for the Six-Minute Walk in healthy adults. Am. J.
Respir. Crit. Care Med. 1998; 158 no. 5: 1384 – 7.
[28]: Torres JP, Casanova C, Hernàndez C, Abreu J, Garcini AM, Aguirre-Jaime A et al. Gender
associated differences in determinants of quality of life in patients with COPD: a case series study
Health and Quality of Life Outcomes. 2006; 4: 72.
APPENDICES
Appendix I: Project plan
Appendix 4a. THE PROJECT PLAN
0. Project
0.1 Name of project The ceiling effect: The 6MWT or «Glittreprotokollen» in COPD patients with high initial functional capacity? - A retrospective observational study
0.2 Participating student
Name: Peter Johnson
E-mail: [email protected]
Telephone: (+47) 47327597
Address: Birkeland, 5392 Storebø, Norway
0.3 Date
12th April, version number: 1.0.
1. Project leader/Commissioner
1.1 Who is responsible
LHL Helse A/S, avdeling; Glittreklinikken
Contact person: Elisabeth Gerhardsen
E-mail: [email protected]
Telephone: (+47) 67058022
Address: Glittreveien 31 (Pb. 104), Åneby 1485
1.2 Supervisory teachers
Frank Vossen (General supervisor):
E-mail: [email protected]
Telephone: (+31) 0877883218
Address: Toledolaan 2, 5629 CC, Eindhoven
Ingrid Janssen (Methodical supervisor)
E-mail: [email protected]
Telephone: (+31) 402642742
Address: Toledolaan 2, 5629 CC, Eindhoven
2. Definition of the problem
2.1. Background
Chronic Obstructive Pulmonary Disease (COPD) is a disease with widely spread clinical
presentations, the shared abnormality being airflow limitations. It is defined as “a preventable and
treatable disease with some significant extra pulmonary effects that may contribute to the severity
in individual patients. Its pulmonary component is characterized by airflow limitation that is not fully
reversible. The airflow limitation is usually progressive and associated with an abnormal
inflammatory response of the lung to noxious particles or gases” [1]. According to the World
Health Organization (WHO), COPD ranks as number four in leading cause of chronic morbidity
and mortality in the US, and further the WHO estimates that the burden of disease will be rated as
fifth worldwide in 2020.
Tests describing the functional capacity of patients with COPD are a cornerstone in determining
the effect of pulmonary rehabilitation [2, 3, 4]. The 6 Minute Walk Test (6MWT) is one of the most
widely used tests in pulmonary rehabilitation (PR) today [3, 4, 5, 6]. It is easy to administer and it
demands little and inexpensive equipment.
Parameters typically measured in PR-candidates besides the 6 minute walking distance (6MWD)
are such as dyspnea measured by the Borg CR10 scale [8] and saturation (SpO2). The Borg
scale has been recommended to measure the effect of PR in relation to the patients subjective
grading of dyspnea and exertion of legs in addition to estimation of training intensity [9].
“The minimal important difference (MID) has become the standard approach for the interpretation
of the clinical relevance of changes in these outcomes induced by respiratory rehabilitation or
other treatments” [10, 11]. The MID of the 6MWD was set by Redelmeier et al. [12] to 54m in
1997. More recently, Puhan et al. opted for a change of the MID from the original 54 m to 35 m [3]
and later to 24 m [5]. This was however in patients with respectively moderate to severe, and
severe COPD.
On the opposite side of the specter there is a well-known ceiling effect related to the 6MWT [13,
14]. This effect is attributed to the combination of the 6MWT limiting the subject to walk and the
physical limitation of how fast it is possible to walk [13, 14]. Using the 6MWT to determine the
effect of PR in subjects with a high initial functional capacity might give the impression of the PR
being without results.
At Glittreklinikken in Hakadal Norway, another test , «Glittreprotokollen», is used to measure the
effects of PR. «Glittreprotokollen» is a modified version of the Bruce treadmill test [15], which has
been adapted to pulmonary patients. The test is performed to the patients symptoms limit
maximum rather than a specified time and further it does not limit the patients to walk.
Therefore the purpose of this study is to find out if the «Glittreprotokollen» is more accurate to measure the effect of PR than the 6MWT in COPD patients with a high initial functional capacity, because of the ceiling effect that is related to the 6MWT. 2.2. Problem definition
The 6MWT is widely used in clinical practice and research to measure the effect of PR [3, 4, 5, 6].
However there exists a ceiling effect of the 6MWT due to the physical limitation of how fast it is
possible to walk [13, 14]. «Glittreprotokollen» is performed to the patients symptoms limit
maximum rather than a specified time and further it does not limit the patients to walk. The goal of
this study is to determine whether the 6MWT or «Glittreprotokollen» is a more accurate tool to
measure the effect of a 4 week in-patient PR program on the functional capacity in COPD patients
with an initial 6MWD ≥ 550 m.
2.3. Presentation of the question(s)
Is «Glittreprotokollen» more accurate in measuring the effect of PR than the 6MWT in COPD patients
with a high initial functional capacity, due to the ceiling effect related to the 6MWT?
2.4. Working definitions
Pulmonary rehabilitation (PR): As defined by ATS/ERS (2006); “Pulmonary rehabilitation is an evidence-based, multi-disciplinary, and comprehensive intervention for patients with chronic respiratory diseases who are symptomatic and often have decreased daily life activities. Integrated into the individualized treatment of the patient, pulmonary rehabilitation is designed to reduce symptoms, optimize functional status, increase participation, and reduce health care costs through stabilizing or reversing systemic manifestations of the disease” [9].
Ceiling effect: The subject reaches near the maximum target of the outcome measure due to the design of the test, and is therefore unable to show much improvement on a following test [13, 16].
Functional capacity: Functional capacity is defined by Kocks WH et al. as “’one’s maximum potential to perform activities” and further he states that it “can be tested, for example, using cycle ergometry” [17]. I have chosen to test the functional capacity by looking at changes in outcomes of the 6MWT and «Glittreprotokollen» pre/post PR. In this study, high functional capacity was defined as a 6MWD ≥ 550m.
3. Objectives
The objective of this study is to determine if either the 6MWT or «Glittreprotokollen» is more accurate
measuring changes in functional capacity of a 4 week in-patient PR program in COPD patients with an
initial 6MWD of ≥ 550m.
4. Project Products
A report dealing with the proposed study
An oral presentation of the findings
5. Method
5.1. Study design
Approach to the research question: Quantitative research.
Research method: Retrospective observational study.
5.2. Participants
N = 20 – 30
5.3. Inclusion/exclusion criteria
All patients were diagnosed with COPD according to the GOLD classification.
All participants were admitted to Glittreklinikken and completed a 4 week in-patient PR program.
All patients had undertaken both a 6MWT and «Glittreprotokollen» pre- and post PR and spirometry testing.
All participants had an initial 6MWD ≥ 550 m on the better of the two initial trails.
All patients had walked at either protocol 3 or 4 during «Glittreprotokollen».
Subjects with electronic data files with relevant missing data were excluded
5.4. Data collection
Data is collected retrospectively from the electronic database at Glittreklinikken A/S. All allegeable
subjects meeting the inclusion criteria in the period between the 15th of November 2010 and the 9
th of
March 2012 will be included. Data will be printed, ID labeled and stored in a folder which will be
located at Glittreklinikken at all times. Data will then be imported to an excel spreadsheet. All data will
be fully anonymous.
The following data will be collected from a database at Glittreklinikken;
Subject characteristics:
Age
Sex
Height
Weight
FEV1%pred
FEV1/FVC
GOLD classification
BMI 1
6 Minute Walk Test:
6MWD
«Glittreprotokollen»:
Maximum velocity
Maximum inclination
5.5. Measurement tools
The 6 Minute Walk Test follows standard procedure and recommendations from the American
Thoracic Society [18]. The test is performed in a corridor with 30m markers. Standard instruction is
given. Standard encouragement phrases are used every minute. The initial test is performed twice,
with a pause of at least 30 min, to account for a learning effect. The test leader is not allowed to walk
together with the patient during the test. 6MWD is noted as well as SpO2 and the patients subjective
grading of dyspnea and exertion of legs according to the modified Borg scale before and after the
completion of the test.
«Glittreprotokollen» is a modified version of the Bruce treadmill test [15], which is adapted to
pulmonary patients. It has a lower initial speed and earlier inclination than the original test. The test is
however not published.
The test is performed to the patients symptoms limit maximum. Pulseoximetry and heart rhythm is
continuously monitored during the test. The test is performed on a treadmill with increasing load every
two minutes based on a set protocol. The subjects are asked to rate their perceived exertion for
dyspnea and legs during the last half minute of each exercise step using the Borg CR-10 scale
(ranging from 0 – 10) [19].
The test is designed with the intention to last about 8-12 minutes and never exceeds 30 minutes.
When patients symptom limit maximum, the inclination is set to 0% and speed to the initial speed
according to the chosen protocol. The last measurements are done at one and three minutes at initial
work rate.
There are four set protocols which primarily differ on initial walking speed. Patients in this particular
study walked on protocol three or four. Which protocol was chosen, was based upon the physical
therapists evaluation of the functional capacity of the patient.
Protocol three started with an initial walking speed of 3.6 km/h and protocol four on 4.8 km/h. The
speed was then increased by 0.6 km/h every 2nd
minute. The speed was increased until 5.4 km/h was
reached. For further increases in workload, the inclination was initially increased by 4%, and then by
2% every 2nd
minute. In protocol three, maximum inclination was reached at 14%, in protocol four
maximum inclination was reached at 8%. For further increases, the speed was increased by 0.6 km/h
every 2nd
minute until a maximum of 8.4 km/h in protocol three and 11.4 km/h in protocol four (table 1).
Table 1. Work load of «Glittreprotokollen» at protocol 3 and 4
Protocol 3 Protocol 4
Km/h Inclination % Km/h Inclination %
0 0
3.6 4.8
4.2 5.4 4
4.8 5.4 6
5.4 5.4 8
5.4 4 5.4 8
5.4 6 6 8
5.4 8 6.6 8
5.4 10 7.2 8
5.4 12 7.8 8
5.4 14 8.4 8
6 14 9 8
6.6 14 9.6 8
7.2 14 10.2 8
7.8 14 10.8 8
8.4 14 11.4 8
3.6 4.8
3.6 4.8
In this study, subjects had to walk on a specific exercise step for at least 30 seconds in order for it to
be registered as the last exercise step achieved.
5.6. Statistical analysis of the data
The data will be analyzed and compared using MedCalc-statistical software.
Descriptive statistics (anthropometric and clinical characteristics)
Age, weight, height, BMI, FEV1 % predicted and FEV1 / FVC will be calculated in terms of
mean, standard deviation (SD), minimum and maximum values. The data will be presented in
tables.
Evaluative statistics
The change in 6MWD will be calculated in %. This will be compared to % change in work rate
(WR) [18] of «Glittreprotokollen», which is one of the most widely used parameters used in
maximum exercise testing [4]. The WR will be displayed as Watts (W). The WR will be
calculated by using the Jaeger formula [22];
a) WRunning: W = (v*BW*(2.11 + G * 0.25) + 2.2 * BW – 151)/10.5 [22] b) WWalking: W = (v*BW*(2.05 + G * 0.29) + 0.6 * BW – 151)/10.5 [22]
WR = (Weight*(Maximum_velocity/3,6*(1,044*Max_inclination+7,524)-0,6)-151)/10,5. [22]
Data will be visually represented by graphs histograms/bar graphs.
6. Management Aspects
6.1 Quality requirements 6.1.1. Boundary conditions
o To make sure that the project products will meet the standards of the Department: The product and the report should mirror the fact that each student has
worked about 550 hours on the project. The product should always be accomplished via ‘pre-testing’ of concepts): In
the case of a research project, the developed research instruments (questionnaire, interview and so on) are tested first as a concept before using them in the definitive data collection.
The report should meet the following demands:
Form: lay-out: A4-format (use Word 97); use font: Arial; Character size in text: 10; character size in tables and figures etc.: 8-10
Volume of report = about 40-60 pages, excluding appendices
Volume of report with separate product = about 20 - 25 pages, excluding appendices
Make sure you correct typing errors and number the pagers. It is up to you if you want to print one-sided or double-sided.
6.1.2. Design Limitations
Hard conclusions in relation to the research question cannot be made. This is due to the
design of the project being a direct comparison of a continuous (6MWT) and stepwise
(Glittreprotokollen) protocol. A described trend or tendency may however be the result of the
study with further recommendations for future research.
Availability of subjects in the electronic database might be limited due to the rigid inclusion
criteria (most COPD patients might not be able to walk ≥ 550 m).
6.2. Timetable
Date(s) Task/Activity
6th – 12
th Feb Development first draft Project plan
12th Feb 1
st Chance: Deadline Go/No Go
Work on project plan
Data collection (as soon as approval FOU)
28th Feb 2
nd Chance: Deadline Go/No Go
Work on project plan
20th March Finished with collection of data before this date
Working on statistics
Working on report
2nd
April Return to Eindhoven
Between these
dates
Preparing meeting, working on framework of article
4th April Meeting with supervisors, deadline 3
rd party assessor
5-11th
April Going through statistics (lectures), working with data,
working with PP
Between 9th and
13th April
Receiving feedback from 3rd
party assessor
11th April Meeting with MS discussing comments (PP), statistics
okay?
12th – 18
th April Finalizing (?) PP, continue work statistics, work on
results, improve framework article.
18th April Meeting with supervisors
18th April - 2
nd
May
Working on article; (discussion?)
2nd
May Meeting with supervisors
2nd
- 16th May Polishing article, peer reviewing
16th May Meeting with supervisors
16th – 28
th May Finalizing article
28th May Deadline end product
Working on presentation
4th – 8
th June Rehearsal presentation
12th June Presentations Graduation Projects
12th June CE-Exam
13th June Exam meeting
15th June Graduation
6.3. Supervision
Starting from 4th of April, there will be scheduled meetings with the general and/or methodological
supervisor every second week until the completion of the project (in total 4 meetings). Besides this,
regular updates of the project plan and progress of the project is encouraged. This also includes
feedback from the general and/or methodological supervisor.
6.4. Estimated Costs
Costs are limited to basic costs (photocopying, binding the report etc.). These are the responsibility of
the student. The cost is estimated to;
Printing: € 15,-
Binding: € 5,-
Total: € 20,-
7. Provisional literature
[1]: Rabe KF, Hurd S, Anzueto A, Barnes PJ, Buist SA, Calverley P et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J. Respir Crit Care Med 2007;176:532-55
[2]: Whipp BJ, Ward SA. Quantifying interventionrelated improvements in exercise tolerance. Eur Respir J 2009;33:1254-1260
[3]: Puhan MA, Mador MJ, Held U, Goldstein R, Guyatt GH, Schünemann HJ. Interpretation of treatment changes in 6-minute walk distance in patients with COPD. WUR Respir J 2008; 32: 637-643.
[4]Sutherland ER, Make BJ. Maximum Exercise as an Outcome in COPD: Minimal Clinically Important Difference. COPD: Journal of Chronic Obstructive Pulmonary Disease 2005, 2:137-141]
[5]: Puhan MA, Chandra D, Mosenifar Z, Ries A, Make B, Hansel NN, Wise RA, Scuriba F. The minimal important difference of exercise tests in severe COPD. Eur Respir J 2011; 37: 784-790.
[6]: Li AM, Yin J, Yu CCW, Tsang T, So HK, Wong E et al. The six-minute walk test in healthy choldren: reliability and validity. Eur Respir J 2005; 25: 1057-1060
[7]: Lacasse Y, Brosseu L, Milne S, et al. Pulmonary rehabilitation for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2004; 4: CD003793
[8]: Nici L, Donner C, Wouters E, Zuwallack R, Ambrosino N, Bourbeau J et al. American Thoracic Society/European Respiratory Society Statement on Pulmonary Rehabilitation. 2005.
[9]: Nici L, Donner C, Wouters E, Zuwallack R, Ambrosino N, Bourbeau J et al. American Thoracic Society/European Respiratory Society Statement on Pulmonary Rehabilitation. Am J Respir Crit Care Med 2006; 173: 1390-1413.
[10]: Revicki DA, Cella D, Hays RD, Sloan JA, Lenderking WR, Aaronson NK. Responsiveness and minimal important difference for patient reported outcomes. Health Qual Life Outcomes 2006; 4: 70.
[11]: Wise RA, Brown CD. Minimal clinically important differences in the six-minute walk test and incremental shuttle walking test. COPD 2005; 2: 125-129.
[12]: Redelmeier DA, Bayoumi AM, Goldstein RS, Guyatt GH. Interpreting small differences in functional status: the six minute walk test in chronic lung disease patients. Am J Respir Crit Care Med 1997; 155: 1278-1282.
[13]: Al-Ghimlas F, Todd DC. Predictors of Success in Pulmonary Rehabilitation for Patients With Interstitial Lung Disease. Chest 2009: 136; 1183-1184.
[14]: Pepin V, Brodeur J, Lacasse Y, Milot J, LeBlanc P, Whittom F, Maltais F. Six-minute walking versus shuttle walking: responsiveness to bronchodilation in chronic obstructive pulmonary disease. Thorax 2007; 62:291-298.
[15]: Grendahl H, Platou ES. Arbeidsbelastning in: Kardiologiske metoder. Oslo: Hjerte Forum Organ for Norsk Cardiologisk Selskap; 1997. p.78-79, 85.
[16]: Jenkins SC. 6-Minute walk test in patients with COPD: clinical applications in pulmonary rehabilitation. Physiotherapy. 2007; 93: 175-182.
[17]: Kocks JWH, Asijee GM, Tsiligianni IG, Kerstjens HAM, Molen T: Functional status measurement in COPD: a review of available methods and their feasibility in primary care. Prim Care Respir J 2011; 20(3): 269-275.
[18]: ATS Statement: Guidelines for the Six-Minute Walk Test. Am J Respir Care Med 2002; Vol 166: 111-117
[19]: Christensen CC, Ryg MS, Edvardsen A, Skjønsberg OH. Relationship between exercise desaturation and pulmonary haemodynamics in COPD patients. Eur Respir J 2004; 24: 580-586
[20]: Hastrup J, Hove L. Den rigtige Borg-skala til vurdering af DYSPNOE; Fysioterapeuten 2008; 10.
[21]: Ries AL. Minimally clinically important difference for the UCSD Shortness of Breath Questionnaire, Borg Scale, and Visual Analog Scale. COPD 2005; 2(1): 105-10.
[22]: Eschenbacher H. Can the exercise on treadmill be indicated in Watt? Viasys Healthcare, respiratory technologies 2009.
Appendix II: Approval project plan
Appendix III: Agreement from Glittreklinikken regarding access to data
Appendix IV: Approval of project plan from Glittreklinikken regarding access to data
Appendix V: Mail from Regional Ethical Committee (REK) regarding ethical approval
Appendix VI: Protocol 6MWT.
Appendix VII: Protocol Glittreprotokollen.
Appendix VIII: Protocol 1 RM leg strength.
Appendix IX: Protocol strength training.
Appendix X: The modified Borg scale.
BORG CR10 SKALA.
Instruksjon: Du skal nå bruke denne skalaen for å fortelle hvor sterk din opplevelse eller følelse er.
Det kan gjelde din opplevelse av anstrengelse, smerte, vanskelighet eller noe annet. Ti (10), ”Ekstremt
sterk”, ”Maksimal”, er et meget viktig intensitetsnivå. Det fungerer som et referansepunkt på skalaen.
Det er den sterkeste opplevelsen eller følelsen (av for eksempel anstrengelse) du noensinne tidligere
har hatt. Det er dog mulig å oppleve eller forestille seg noe som er enda sterkere. Derfor finnes
”Absolutt maksimum” utenfor eller noe lenger ned på skalaen uten noen bestemt siffer og markert med
et punktum ”·”. Hvis din opplevelse eller følelse er sterkere enn ”10”, kan du bruke et høyere tall.
Se først på de muntlige uttrykkene og velg så et tall. Dersom din opplevelse eller følelse er ”Svært
svak”, velger du ”1”, dersom den er ”Moderat”, velger du ”3”. Tenk på at ”Moderat” er ”3” og altså
svakere enn ”Middels” eller ”Midten”. Dersom opplevelsen din er ”Sterk” eller ”Kraftig” (det føles
”Tungt” eller oppgaven er ”Vanskelig”) sier du ”5”. Legg merke til at ”Sterk” er omtrent 50 prosent, dvs.
halvparten, av ”Maksimal”. Er den ”Svært sterk velger du tall fra 6 til 8, avhengig av hvor sterk den er.
Du kan godt bruke halve tall, for eksempel ”1,5” eller ”3,5”, eller desimaltall som ”0,3”, ”0,8”, eller ”2,3”:
Det er veldig viktig at du gir uttrykk for det som du opplever eller føler, og ikke hva du tror du bør si.
Vær så ærlig og spontan som mulig og ikke forsøk verken å overvurdere eller undervurdere. Begynn
med et muntlig uttrykk og velg så et tall.
Ved gradering av anstrengelse vil vi at du skal angi et tall for din opplevelse av anstrengelse, dvs. hvor
tungt og slitsomt du føler arbeidet er og hvor sliten du føler deg. Opplevelsen av anstrengelse
avhenger hovedsakelig av trettheten i musklene dine, om du føler deg andpusten og eventuell
smerte. Det er viktig at du nå bare tar hensyn til hva du føler og ikke på hva belastningen er egentlig
er.
0 ”Ingen anstrengelse i det hele tatt” betyr at du ikke rører på deg, bare ligger og hviler
1 Meget lett. Som for en frisk person å gå en kort tur i sitt eget tempo.
3 Moderat er noe, men ikke spesielt anstrengende. Det føles greit, og det er ikke noe problem
å fortsette.
5 Arbeidet er anstrengende og slitsomt, men du har ikke store vanskeligheter med å fortsette.
Anstrengelsen er omtrent halvparten så sterk som ”Maksimal”
7 Meget anstrengende, en veldig sterk påkjenning. Du kan fortsette, men må presse deg selv
hardt og du er meget sliten.
10 Et ekstremt høyt nivå. Dette er det hardeste de fleste mennesker noen gang har opplevd
tidligere.
· Er ”Absolutt maksimum, for eksempel ”12” eller ende høyere.
Gradering av smerte: Du skal nå gradere hva du har for smerte og hvor sterk den er. Det som står
skrevet over angående anstrengelse er bra å kjenne til for å forstå hvordan skalaen fungerer.
Hva er den verste, sterkeste opplevelse av smerte du noen gang har hatt? Tenk etter og fortell
hvordan det føltes. Kall din sterkeste, mest intense smerteopplevelse for ti (”10”).
10 ”Ekstremt sterk - Maksimal” er det viktigste referansepunktet. Bruk ”10” for den sterkeste smerteopplevelse du noensinne har hatt; den du akkurat har beskrevet.
· Er ”Absolutt maksimum”. Det kan finnes smerte som er ende verre enn den du selv noensinne tidligere har opplevd. Dersom den følelsen er noe sterkere velger du ”11” eller ”12”.
Begynn med et muntlig uttrykk og velg så et tall. Forsøk kun å bedømme bare selve smerten og ikke
hva den betyr for deg, hvilke ubehag du har eller hvor sterkt du lider. Slike følelser er selvfølgelig også
viktige, men det må du prøve å angi separat.
Noen spørsmål?
