10
ORIGINAL ARTICLE Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons Rafael Denadai Andre ´ia Padilha Toledo Marie Oshiiwa Roge ´rio Saad-Hossne Received: 14 August 2012 / Accepted: 16 January 2013 / Published online: 13 February 2013 Ó Springer-Verlag Italia 2013 Abstract Due to shortage of time and limited availability of faculty surgeons to teach basic surgical skills during medical graduation, the search for alternative ways of simulated training with feedback is needed. The purpose of this study was to compare the simulated teaching of suture skills to novice medical students by senior medical students and by experienced faculty surgeons. Forty-eight novice medical students were randomly assigned to three practice conditions on bench model (n = 16): self-directed suture training (control), senior medical student-directed suture skills’ training, or experienced faculty surgeon-directed suture skills’ training. Pre- and post-tests were applied. Global Rating Scale with blinded evaluation and self-per- ceived confidence based on Likert scale were used to assess all suture performances in pre- and post-training. Effect size was also calculated. The analysis made after training showed that the students who received feedback from the instructors had better performance based on the Global Rating Scale (all p \ 0.0000) and felt more confident to carry out sutures (all p \ 0.0000) when compared to the control. There was no significant difference (all p [ 0.05) between the student-directed teaching and faculty-directed teaching groups. The magnitude of the effect (instructor- directed training suture) was considered large ( [ 0.80) in all measurements. The acquisition of suture skills after stu- dent-directed training was similar to the training supervised by faculty surgeon, and the increase in suture performances of trainees that received instructor administered training was superior to self-directed learning. Keywords Feedback Á Medical education Á Medical student Á Surgery Á Sutures Á Teaching Introduction Once the suture technique is the foundation upon which most surgical skills will be built [1] and suture basic skill is not acquired by a large percentage of medical students [2], suture skills’ training become an important component of the undergraduate training period [3]. In order to teach sutures and bearing in mind that the performance of basic surgical skills’ training on live patients (traditional apprenticeship model) may violate ethical and medico-legal aspects [4], learning technical skills on low-cost bench models [510] is becoming widely used during medical education [11]. In this sense (simulated training), a combination of self- directed training with feedback was recently described as an excellent method to teach basic technical skills [12]. On surgical training, concurrent (or process) and summary (or outcome) feedback is associated with better and faster learning, and also with greater long-term knowledge retention [13]. Feedback can be performed by computers R. Denadai Institute of Plastic and Craniofacial Surgery, Brazilian Society of Research and Assistance to Craniofacial Rehabilitation Hospital (SOBRAPAR), Campinas, SP, Brazil R. Denadai Á A. P. Toledo Á R. Saad-Hossne Department of Surgery, Botucatu Medical School, University of the State of Sa ˜o Paulo (UNESP), Botucatu, SP, Brazil R. Denadai (&) Paula Fabiana Tudela 161–Esmeralda, 17516-707 Marı ´lia, Sa ˜o Paulo, Brazil e-mail: [email protected] M. Oshiiwa Department of Statistics, Faculty of Technology, FATEC, Marilia, SP, Brazil 123 Updates Surg (2013) 65:131–140 DOI 10.1007/s13304-013-0199-y

Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

Embed Size (px)

Citation preview

Page 1: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

ORIGINAL ARTICLE

Acquisition of suture skills during medical graduationby instructor-directed training: a randomized controlledstudy comparing senior medical students and faculty surgeons

Rafael Denadai • Andreia Padilha Toledo •

Marie Oshiiwa • Rogerio Saad-Hossne

Received: 14 August 2012 / Accepted: 16 January 2013 / Published online: 13 February 2013

� Springer-Verlag Italia 2013

Abstract Due to shortage of time and limited availability

of faculty surgeons to teach basic surgical skills during

medical graduation, the search for alternative ways of

simulated training with feedback is needed. The purpose of

this study was to compare the simulated teaching of suture

skills to novice medical students by senior medical students

and by experienced faculty surgeons. Forty-eight novice

medical students were randomly assigned to three practice

conditions on bench model (n = 16): self-directed suture

training (control), senior medical student-directed suture

skills’ training, or experienced faculty surgeon-directed

suture skills’ training. Pre- and post-tests were applied.

Global Rating Scale with blinded evaluation and self-per-

ceived confidence based on Likert scale were used to assess

all suture performances in pre- and post-training. Effect

size was also calculated. The analysis made after training

showed that the students who received feedback from the

instructors had better performance based on the Global

Rating Scale (all p \ 0.0000) and felt more confident to

carry out sutures (all p \ 0.0000) when compared to the

control. There was no significant difference (all p [ 0.05)

between the student-directed teaching and faculty-directed

teaching groups. The magnitude of the effect (instructor-

directed training suture) was considered large ([0.80) in all

measurements. The acquisition of suture skills after stu-

dent-directed training was similar to the training supervised

by faculty surgeon, and the increase in suture performances

of trainees that received instructor administered training

was superior to self-directed learning.

Keywords Feedback � Medical education �Medical student � Surgery � Sutures � Teaching

Introduction

Once the suture technique is the foundation upon which

most surgical skills will be built [1] and suture basic skill is

not acquired by a large percentage of medical students [2],

suture skills’ training become an important component of

the undergraduate training period [3].

In order to teach sutures and bearing in mind that the

performance of basic surgical skills’ training on live

patients (traditional apprenticeship model) may violate

ethical and medico-legal aspects [4], learning technical

skills on low-cost bench models [5–10] is becoming widely

used during medical education [11].

In this sense (simulated training), a combination of self-

directed training with feedback was recently described as

an excellent method to teach basic technical skills [12]. On

surgical training, concurrent (or process) and summary (or

outcome) feedback is associated with better and faster

learning, and also with greater long-term knowledge

retention [13]. Feedback can be performed by computers

R. Denadai

Institute of Plastic and Craniofacial Surgery, Brazilian Society

of Research and Assistance to Craniofacial Rehabilitation

Hospital (SOBRAPAR), Campinas, SP, Brazil

R. Denadai � A. P. Toledo � R. Saad-Hossne

Department of Surgery, Botucatu Medical School, University

of the State of Sao Paulo (UNESP), Botucatu, SP, Brazil

R. Denadai (&)

Paula Fabiana Tudela 161–Esmeralda, 17516-707 Marılia,

Sao Paulo, Brazil

e-mail: [email protected]

M. Oshiiwa

Department of Statistics, Faculty of Technology,

FATEC, Marilia, SP, Brazil

123

Updates Surg (2013) 65:131–140

DOI 10.1007/s13304-013-0199-y

Page 2: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

[14], physicians such as experienced faculty surgeons [1,

12, 14–16], and residents [17], and non-physicians such as

laboratorial technicians [18, 19], and medical students [20].

Especially, medical student-directed learning has the

benefit of being a more informal teaching and allowing

students to solve their doubts without feeling foolish [20,

21]. Besides, in general, students enjoy being taught by

other students because the interaction is easier and often

the way in which the skill is taught is placed in context for

their level of experience [21, 22].

Although several researches [20, 23–27] have descri-

bed similar effectiveness between medical student-assis-

ted learning and faculty expert-assisted learning, the

understanding of the impact and effectiveness of specific

suture technique teaching on bench models by medical

students evaluated in an objective manner is relatively

unknown.

Such information led us to hypothesize that the teaching

of suture skills by senior medical students will be as

effective as the traditional methodology administered by

faculty surgeons. The purpose of this study was to compare

senior medical students with experienced faculty surgeons

in the teaching of suture skills to novice medical students

on inanimate bench models, by means of a randomized

controlled blinded study.

Methods

Subjects

The protocol consisted of 48 first- and second-year medical

students with no surgical skills background (novices) from

a single academic center that volunteered to participate in

the study, enrolled upon a consent form signed by them, in

accordance with the Helsinki Declaration of 1975, as

amended in 1983. Local institutional research ethics board

approval was obtained for this study.

Study design

The design was a randomized controlled study with

blinding of expert examiners, including a pre-test, a 1-h

practice phase, and a post-test (Fig. 1). The pre- and post-

tests were identical and consisted of the manufacture of

five simple interrupted sutures (bidimensional; simple

wound closure) and one running subcuticular suture (tri-

dimensional; advanced wound closure) for the closure of

two elliptical incisions measuring 8 9 2 cm each on ox

tongue. Each student was tested individually and had a

total of 5 min for each task. No verbal feedback was pro-

vided during both pre- and post-tests.

Pre testing

On the day of the experiment, all participants were taught

how to use surgical instruments, as well as the techniques

for both types of sutures (simple interrupted sutures and

running subcuticular sutures) required by means of an

instructional video [28] presentation that was repeated and

commented for 1 h (verbal teaching based on video)

[1, 14]. Next, all participants underwent a pre-test.

Group assignment and training phase

Immediately after the pre-test, all students were randomly

allocated via a computer-generated process to one of the

three study groups (n = 16). All three groups remained

in separated rooms so they were unable to communicate

with each other. In group 1 (control), students were given

a self-directed suture training on bench model based on

didactic materials (manuscripts, textbooks, on-line text

and on-line narrated expert demonstration videos) on the

handling of surgical instruments and the manufacture of

sutures. The rest of the participants received guidance on

the handling of surgical instruments and trained sutures

in a repetitive and deliberative manner on bench models

directly supervised by a senior medical student (group 2)

or by an experienced faculty surgeon (group 3). This

stage lasted 1 h [1, 14] for all the three groups.

Apparatus for hands-on training

The whole process of teaching, learning, and training of

sutures given to students of the three groups was performed

on synthetic ethylene–vinyl acetate bench model (Fig. 2)

according to features recently described by our group

[7–9]. The original article [7] on the ethylene–vinyl acetate

bench model was translated into the native language of

students from group 1 (Brazilian Portuguese) in order to be

adopted as a teaching tool.

Instructors and feedback

The medical students chosen to be instructors were vol-

unteers recruited from the group of final-year (senior)

students; they were interviewed and selected according to

the criteria described by Wadoodi and Crosby [20] and by

Sobral [29]. The faculty surgeons, working as instructors,

had more than 10 years of experience in teaching basic and

advanced surgical skills to students and residents; they are

not co-authors of this study and did not participate in the

process of blinded evaluation of maneuvers carried out in

pre- and post-tests.

132 Updates Surg (2013) 65:131–140

123

Page 3: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

In order to standardize the teaching and learning in

groups 2 and 3, it one instructor for every four students [1]

was used; all instructors were randomly allocated via a

computer-generated process to one of eight semi-groups

with four students each. On standardized didactic seminar,

all instructors were told to teach the suture skills using the

same method; during concurrent and summary feedback

important aspects to promote good wound healing and good

aesthetic results (e.g., instrument handling, correct posi-

tioning of the needle in the needle holder, angle of needle

entry in the ‘‘skin’’, exit of the needle at a point equidistant

from the insertion point for both pricks, approximation of

the ‘‘wound edges’’ with appropriate tension level, eversion

and apposition of the ‘‘wound edges’’, and meticulous

‘‘tissue’’ handling) [30, 31] were taught to all students.

Post-testing

Immediately after the training phase, all medical students

were randomly allocated to post-test.

Fig. 1 Pre- and post-training study design

Fig. 2 Synthetic ethylene–vinyl acetate bench model simulating (a, b) a ‘‘cutaneous wound’’, a (c, d) simple interrupted suture, and (e, f) a

running subcuticular suture

Updates Surg (2013) 65:131–140 133

123

Page 4: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

Study blinding

All 192 pre- and post-test maneuvers were recorded

(images focusing only on hand movements) and saved.

These digital videos were archived for later analysis and

codified using randomly assigned numbers by one of the

investigators. All digital videos were evaluated in a blinded

fashion independently by two experienced surgical spe-

cialists that had no prior knowledge on the groups and that

did not take part in the training processes.

Outcome measures

All 48 study participants completed pre- and post-training

questionnaires aimed at measuring self-perceived confidence

in performing sutures; they rated their confidence level on a

5-point Likert Scale [6], the lowest rating (‘‘very unconfi-

dent’’) being 1 and the highest being 5 (‘‘very confident’’).

The quantitative evaluation was based on the number of

students that completed one or more stitches and on the

number of stitches finalized for each group; only after the

ends of the two surgical threads were cut, the stitch was

considered finalized. The Global Rating Scale (Table 1)

[32, 33] was used to evaluate objectively (qualitative

assessment) the suture performance of each student in eight

main areas, each of which was rated on a behaviorally

anchored 5-point scale; with 1 being the minimum score

and 5 the maximum score for a total maximum score of 40.

Statistical analysis

In the descriptive analysis, data were summarized as mean

values, medians, standard deviations, 1st and 3rd quartiles,

minimum and maximum values. Bioestat� for Windows

version 5.0 was used to perform statistical analyses. Stu-

dent’s t test was used for measurable variables and Fisher’s

test for the analysis of categorical variables, due to the

small sample set. Values were considered significant for a

confidence interval of 95 % (p \ 0.05). Effect sizes were

also calculated to identify the magnitude of the intervention

effect regardless of the sample size; effect sizes exceeding

0.80 were considered large [34].

Results

Quantitative suture skills’ assessment

During pre-test none of the 48 participants was able to

carry out any of the two proposed types of sutures and

Table 1 Global Rating Scale [32, 33] used to assess qualitatively and objectively all suture performances

Please rate the candidate’s performance on the following scale

1 2 3 4 5

Respect

for tissue

Frequently used unnecessary

force on tissues or caused

damage by inappropriate

instrument use

Careful handling of tissue,

but occasional

inadvertent damage

Consistently handled

tissues appropriately

with minimal damage

Time in

motion

Many unnecessary moves Efficient time and motion,

but some unnecessary

moves

Clear economy of

movement and

maximum efficiency

Instrument

handling

Repeatedly makes tentative

or awkward moves with

instruments

Competent use of instruments,

but occasionally awkward

Fluid movements

Suture skill Awkward and unsure with

poor knot tying,

and inability to

maintain tension

Competent suturing with

good knot placement

and appropriate tension

Excellent suture control

with correct suture

placement and tension

Flow of

operation

Frequently stopped operating,

seemed unsure of next move

Demonstrated some forward

planning and reasonable

progression of procedure

Obviously planned

operation

Knowledge

of procedure

Inefficient knowledge

of procedure. Looked

unsure and hesitant

Knew all important

steps of procedure

Demonstrated familiarity

of all steps of procedure

Final product Final product of

unacceptable quality

Final product of

average quality

Final product

of superior quality

Overall

performance

Very poor Competent Very good

Total score: ()

n.s. means that p [ 0.05

134 Updates Surg (2013) 65:131–140

123

Page 5: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

therefore, there are no differences in the comparative

analyses among all the three groups (all p [ 0.05). In the

post-test, a larger number of students (all p \ 0.05) of

groups 2 and 3 carried out a greater number of both types

of sutures (all p \ 0.05) when compared with group 1

(Table 2); there were no differences in the comparisons

between groups 2 and 3 (all p [ 0.05). Comparing pre-test

with post-test, a larger number of students (all p \ 0.05) of

groups 2 and 3 made a greater number of both suture types

in the post-test (all p \ 0.05), and there were no differ-

ences for group 1 (all p [ 0.05).

Objective suture skills’ evaluation

In blinded evaluations of all maneuvers performed in pre-

and post-training, no inter-observer difference was detected

among the examiners on the qualitative evaluation of mean

values in all the three groups for both types of sutures (all

p [ 0.05).

In all performances, the mean values of qualitative

assessments performed in the pre-test were \8.25, and

there were no differences between group-to-group com-

parisons (all p [ 0.05) (Table 3). The objective and qual-

itative analysis of simple interrupted sutures and running

subcuticular sutures performances in the post-training

showed that groups 2 and 3 compared to group 1 presented

a better performance (all p = 0.0000). There was no dif-

ference (all p [ 0.05) in the comparison between groups 2

and 3 for both suture performances (Table 3; Fig. 3).

Comparing pre-test and post-test, there was a better per-

formance of all three groups in the manufacture of simple

interrupted sutures (p = 0.0029 for group 1; p = 0.0000

for groups 2 and 3) and of running subcuticular sutures

(p = 0.0000 for groups 2 and 3) in the post-training, except

in group 1 (p = 0.4391) (Table 3; Fig. 4).

Effect sizes

The evaluation of the intervention magnitude (suture

training) was considered large (C0.80) in all measurements

made, except for the manufacture of running subcuticular

sutures by students in group 1 (Table 3).

Self-perceived confidence

Regarding the perception of students about their confidence

to perform both suture techniques, all 48 students were

very unconfident (all mean values equal to 1.0) before

training; therefore, there are no differences in the group-

to-group comparisons (all p = 0.5000) (Table 4). After

training, although students from groups 2 and 3 were

similar (p [ 0.05) among themselves, they felt more con-

fident (all p = 0.0000) to perform both types of sutures

when compared to trainees from group 1 (Table 4; Fig. 5).

When comparing pre- and post-training, there was

increased confidence (all p \ 0.05) in all three groups to

perform both suture techniques after training (Table 4;

Fig. 6).

Discussion

Since the majority of general practitioners that perform

minor surgical procedures such as cutaneous surgery do not

have any formal surgical training [31], and the ability to

close a wound correctly is an essential and important skill

in the general practice setting, because poor suturing

technique is directly related to adverse wound healing and

increased scarring [30, 31], it is necessary to teach suturing

to undergraduates [3]. In addition, current acquisition

of suture skills outside the operating environment on

Table 2 Quantitative comparison between the number of students that completed at least one stitch and the number of stitches performed in

post-training by each group

Variable Simple interrupted sutures Running subcuticular sutures

Group 1

N (%)

Group 2

N (%)

Group 3

N (%)

p value Group 1

N (%)

Group 2

N (%)

Group 3

N (%)

p value

Students who have stitches

(N = 16)

4 (25) 16 (100) 16 (100) * 0 16 (100) 16 (100) *

Total number of stitches (N = #) 4 (5.0) 40 (50) 42 (52.5) * 0 16 (100) 16 (100) *

Number of stitches for student

(M ± SD)

0.25 ± 0.46 2.5 ± 0.75 2.625 ± 0.51 0 1.0 ± 0 1.0 ± 0

Group 1, self-directed suture training (Control); Group 2, senior medical student-directed suture training; Group 3, faculty-directed suture

training

M mean, SD standard deviation* p \ 0.05 for all comparisons between all three groups (Group 1 \ Group 2 = Group 3), except for group 2 versus group 3 (p [ 0.05)# N = 80 for simple interrupted sutures and N = 16 for running subcuticular sutures

Updates Surg (2013) 65:131–140 135

123

Page 6: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

Table 3 Mean of the objective and qualitative assessments based on Global Rating Scale pre- and post-training and the effect size (suture

training) of both suture performances

Variable Simple interrupted sutures Running subcuticular sutures

Group 1 Group 2 Group 3 Group 1 Group 2 Group 3

Pre-test (M ± SD)� 8.25 ± 0.45 8.25 ± 0.45 8.125 ± 0.34 8.125 ± 0.34 8.125 ± 0.34 8.25 ± 0.45

Post-test (M ± SD)¥ 10.44 ± 1.55 22.81 ± 2.61 22.94 ± 2.51 8.31 ± 0.34 20.5 ± 2.19 20.56 ± 1.82

Mean difference 2.19 14.56 14.82 0.19 12.38 12.31

p value* 0.0029 0.0000 0.0000 0.4391 0.0000 0.0000

Effect size# 4.87 32.35 43.58 0.56 36.41 27.36

Group 1, self-directed suture training (Control); Group 2, senior medical student-directed suture training; Group 3, faculty-directed suture

training

M mean, SD standard deviation� p [ 0.05 for all comparisons between all three groups (Group 1 = Group 2 = Group 3)¥ p = 0.0000 for all comparisons between all three groups (Group 1 \ Group 2 = Group 3), except for group 2 versus group 3 (p [ 0.05)* Should be considered statistically significant (pre-test versus post-test) if p \ 0.05# Should be considered a large effect if [0.80

Fig. 3 Boxplot showing the dispersion of the mean values of all (left)simple interrupted suture performances and (right) running subcutic-

ular suture performances in the post-test based on Global Rating

Scale. Groups 2 (senior medical students-directed training) and 3

(faculty-directed training) were similar to each other, but presented a

significantly better performance compared to control group 1. The

diamond symbol represents the mean value. The heavy line is the

median. The bars represent the data range. The symbol ‘‘asterisk’’

indicates the outliers

Fig. 4 Mean of all (left) simple interrupted suture performances and

(right) running subcuticular suture performances in pre- and post-tests

based on Global Rating Scale. Groups 2 (senior medical student-

directed training) and 3 (faculty-directed training) were similar to

each other (all p [ 0.05), but improved their qualitative performance

significantly more (all p = 0.0000) than control group 1

136 Updates Surg (2013) 65:131–140

123

Page 7: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

inanimate bench models is recommended prior to proce-

dures on live patients [4].

In this context (teaching sutures on simulators), since it

was showed that retention of surgical skills is stronger when

acquired in a manner interspersed with rest periods (several

training sessions), instead of teaching at one time [35], this

form of teaching should be adopted to retain and improve

the skills of learned sutures [12, 35]. However, some factors

such as high financial costs [35], lack of time, and avail-

ability of faculty experts [12, 15, 19, 36] have been

Table 4 Students’ perception on their confidence to perform sutures in pre- and post-training based on 5-point Likert scale

Variable Simple interrupted sutures Running subcuticular sutures

Group 1 Group 2 Group 3 Group 1 Group 2 Group 3

Pre-training (M ± SD)� 1.0 ± 0 1.0 ± 0 1.0 ± 0 1.0 ± 0 1.0 ± 0 1.0 ± 0

Post-training (M ± SD)¥ 1.37 ± 0.52 3.125 ± 0.64 3.25 ± 0.71 1.25 ± 0.46 2.625 ± 0.52 2.625 ± 0.52

p value* 0.0398 0.0000 0.0000 0.0852 0.0000 0.0000

Group 1, self-directed suture training (Control); Group 2, senior medical student-directed suture training; Group 3, faculty-directed suture

training

M mean, SD standard deviation� p [ 0.05 for all comparisons between all three groups (Group 1 = Group 2 = Group 3)¥ p = 0.0000 for all comparisons between all three groups (Group 1 \ Group 2 = Group 3), except for group 2 versus group 3 (p [ 0.05)* Should be considered statistically significant (pre-training versus post-training) if p \ 0.05

Fig. 5 Boxplot showing the dispersion of the mean values of

students’ perceptions about their confidence to perform (left) simple

interrupted sutures and (right) running subcuticular sutures in the

post-training based on 5-point Likert scale. Groups 2 (senior medical

student-directed training) and 3 (faculty-directed training) were

similar to each other, but presented significantly better confidence

than control group 1. The diamond symbol represents the mean value.

The heavy line is the median. The bars represent the data range

Fig. 6 Mean of students’ perceptions, all of the three groups, on their

confidence to perform (left) simple interrupted sutures and (right)running subcuticular sutures pre- and post-training based on 5-point

Likert scale. Groups 2 (senior medical student-directed training) and 3

(faculty-directed training) were similar to each other (all p [ 0.05),

but improved their confidence significantly more (all p = 0.0000)

than control group 1

Updates Surg (2013) 65:131–140 137

123

Page 8: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

described as limiting factors for the implementation of this

teaching strategy over a predetermined period (weeks or

months).

In recent years, in order to reduce partially the financial

costs, different alternative methodologies such as training on

low-cost inanimate bench models have been proposed, dis-

cussed, and evaluated by our group [7–10] and by others [5, 6].

Availability of time, however, remains an issue for experi-

enced faculty surgeons that are removed from the patient care

setting to teach in simulation environments [12, 36].

Computer-generated feedback can be an option to

reduce the learning time supervised by faculty surgeons.

However, besides the high cost the retention of skills over

time is significantly greater when learned from direct

feedback from an instructor [15], and it has been demon-

strated that computer-assisted feedback is not effective for

teaching two-handed square knots to novice medical stu-

dents [37]. Alternatives that can also help to reduce

supervised teaching time would be increasing the intervals

between training sessions [38] and encouraging the prac-

tice outside the classroom (e.g., at home) [7–10].

Moreover, the incorporation of residents as teachers [17]

can also decrease the need for expert-administered training.

However, as residents also have limited time devoted to

teaching students [39] and resident-assisted teaching was

described as similar to student-assisted teaching [21],

medical students [20] appear as alternatives that may reduce

the number of faculty experts and residents that are trans-

ferred from surgical practice to the simulation laboratory.

Although there is the intuitive belief that the acquisition

of suture skills with the faculty surgeon-directed surgeon

training is superior to the student-directed training, such

statement cannot be merely subjective [40] because it does

not express the real level of acquired skills [41]. Moreover,

in the training of surgical skills the acquisition of compe-

tences should be assessed by an objective method [40, 42].

Thus, in the present study, the previously validated Global

Rating Scale [32, 33] was used as a tool for measurement

and certification to evaluate objectively all the suture per-

formances. This scale is part of the Objective Structured

Assessment of Technical Skills [32, 33], which is consid-

ered the gold standard for objective assessment of technical

surgical skills [40, 42].

In the present study, the conduction of a pre-test after

viewing an instructional video [1, 14, 16, 35] and the use of

a control group with self-directed didactic training on

bench model [12, 14, 16] were based on studies about

teaching basic surgical skills to medical students or resi-

dents. For the blind evaluation of the 192 recorded videos,

the evaluators were able to fast-forward through the tapes,

a procedure that shortened evaluation time and that has

been shown to be as effective as viewing the entire skill at

its natural pace [43]. Bi- and tridimensional sutures were

evaluated due to the existence of different complexities for

teaching and learning such techniques [7, 9, 10].

During the regular practical activities in our academic

center and during the course of previous studies [7–10], it

was subjectively noted that some medical students that

mastered the sutures techniques could help in the teaching

of those with less technical mastery. Therefore, this study

was designed to investigate objectively if senior medical

students are effective to teach sutures on bench models to

novice medical students.

Final-year medical students (year 6) were recruited to be

trainers because they had received training of suture skills

on inanimate bench models [7–10] and put the learned

skills into practice on living patients at different times such

as stages of instrumental technique (year 3), ambulatory

surgery (years 3 and 4), emergency room (years 5 and 6),

and clinical surgery (years 4, 5 and 6). Besides, since

medical students express interest in learning teaching skills

and teaching during medical graduation [44], the use of

students as instructors has been proposed not only to help

meet the increasing demand for experienced faculty sur-

geons, but also to serve as a useful educational tool for

senior students as they prepare for careers that may involve

teaching such as faculty [23].

Although several studies [12, 14–16] in the surgical

literature have evaluated important aspects of surgical

skills’ training based on feedback, according to an English

literature review (Medline, Scopus and Embase databases)

this is one of the few studies that have evaluated objec-

tively if the acquisition of suture skills by novice medical

students from senior student-directed learning is as effec-

tive as the learning from experienced faculty surgeon; there

are similar reports on medical students teaching other

technical skills [21, 23–27].

As observed in other studies [6, 14], before the training

phase the students were not able to perform the proposed

tasks quantitatively and qualitatively. Comparing the pre-

test with the post-test, a larger number of trainees that

received feedback from senior medical students (group 2)

and from faculty surgeon (group 3) showed quantitative

and qualitative increase in suture performance when com-

pared with the self-directed training group (control).

No differences were observed when comparing the

instructor-assisted groups (2 similar to 3), demonstrating

that senior medical student-directed training is a successful

method for learning suture procedures on bench models,

and it can be as effective as the training provided by

experienced faculty surgeon. Similar results on the acqui-

sition of different technical skills, such as internal medicine

skills [23–25], advanced life support [26], and others [27]

have been described.

In the present study, the effect sizes (instructor-directed

suture training) were large, indicating that the significant

138 Updates Surg (2013) 65:131–140

123

Page 9: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

improvement was most likely related to the intervention

and not to sample size [34]. The evaluations of all 192

suture performances carried out by two independent and

blinded raters decreased the possibility that this increase in

performances was a result of rater bias or expectations

from the non-blinded faculty surgeon raters [6]. This study

also showed that after 1-h training session there was an

increase in confidence levels for the execution of the two

suture skills taught, similar to that observed by others [18].

Based on similar results found in the present study

(suture teaching by senior medical student was similar to

by faculty surgeon) and on the teaching methodology

adopted at Southern Illinois University (non-physician

skills coach help in the training of students and residents)

[18], the authors believe that senior medical students that

master the techniques of suture can be incorporated in an

alternative and complementary way to the teaching by

faculty experts. Thus, medical students would be respon-

sible only for the technical skill teaching (suture training),

and faculty surgeons would focus on teaching complex

tasks, complete procedures, and cognitive aspects of clin-

ical teaching (decision making) that are not duties of the

non-physician instructor [18].

The present study assessed only a basic surgical skill

(suture training) and does not meet all the needs of medical

students in training, which should include the acquisition of

other tasks and surgical skills, such as performing knot-

tying, dissection, excision, and ligating structures [12] that

can also be trained in simulation environments [36];

therefore, care should be taken about the generalization of

results to other technical skills.

The limitations of our study include the relatively small

number of first- and second-year medical students and

instructors. Although similar to a number of other studies

which also evaluated surgical skills [12, 19, 32], this should

be considered when reviewing the results of this study. A

prospective study including a larger number of both sub-

jects and instructors should be encouraged and designed to

verify and support our findings. Moreover, further studies

are required to measure the retention of suture skills taught

by final-year medical students over time, the transferability

to surgical practice, and to access if students in other levels

of training (e.g., third- and fourth-year medical students)

may also be incorporated as instructors in the process of

teaching and learning of suture skills.

In summary, the present study demonstrated that the

acquisition of bi- and tridimensional suture skills on

inanimate bench models by novice medical students after

senior medical student-directed training was similar to the

training supervised by faculty surgeon, and the quantita-

tive/qualitative increase of suture performances in partici-

pants that received instructor-directed training was superior

to self-directed learning.

Conflict of interest None.

References

1. Dubrowski A, MacRae H (2006) Randomised, controlled study

investigating the optimal instructor: student ratios for teaching

suturing skills. Med Educ 40(1):59–63

2. Forbes SS, Fitzgerald PG, Birch DW (2006) Undergraduate

surgical training: variations in program objectives and curriculum

implementation across Canada. Can J Surg 49(1):46–50

3. Friedlich M, Wood T, Regehr G, Hurst C, Shamji F (2002)

Structured assessment of minor surgical skills (SAMSS) for

clinical clerks. Acad Med 77(10 Suppl):S39–S41

4. Hammond I, Karthigasu K (2006) Training, assessment and

competency in gynaecologic surgery. Best Pract Res Clin Obstet

Gynaecol 20(1):173–187

5. Tokuhara KG, Boldt DW, Yamamoto LG (2004) Teaching

suturing in a workshop setting: a comparison of several models.

Hawaii Med J 63(9):258–259

6. Tache S, Mbembati N, Marshall N, Tendick F, Mkony C,

O’Sullivan P (2009) Addressing gaps in surgical skills training by

means of low-cost simulation at Muhimbili University in Tan-

zania. Hum Resour Health 7:64

7. Bastos EM, Silva RD (2011) Proposal of a synthetic ethylene-

vinyl acetate bench model for surgical foundations learning.

Suture training. Acta Cir Bras 26(2):149–152

8. Denadai R, Bastos EM (2012) The synthetic ethylene-vinyl

acetate bench model. Dermatol Surg 38(2):288–289

9. Denadai R, Saad-Hossne R, Oshiiwa M, Bastos EM (2012)

Training on synthetic ethylene-vinyl acetate bench model allows

novice medical students to acquire suture skills. Acta Cir Bras

27(3):271–278

10. Denadai R, Souto LR (2012) Organic bench model to comple-

ment the teaching and learning on basic surgical skills. Act Cir

Bras 27(1):88–94

11. Reznick RK, MacRae H (2006) Teaching surgical skills-changes

in the wind. N Engl J Med 355(25):2664–2669

12. Jensen AR, Wright AS, Levy AE, McIntyre LK, Foy HM,

Pellegrini CA, Horvath KD, Anastakis DJ (2009) Acquiring basic

surgical skills: is a faculty mentor really needed? Am J Surg

197(1):82–88

13. Cannon-Bowers JA, Bowers C, Procci K (2010) Optimizing

learning in surgical simulations: guidelines from the science of

learning and human performance. Surg Clin North Am 90(3):

583–603

14. Xeroulis GJ, Park J, Moulton CA, Reznick RK, Leblanc V,

Dubrowski A (2007) Teaching suturing and knot-tying skills to

medical students: a randomized controlled study comparing

computer-based video instruction and (concurrent and summary)

expert feedback. Surgery 141(4):442–449

15. Porte MC, Xeroulis G, Reznick RK, Dubrowski A (2007) Verbal

feedback from an expert is more effective than self-accessed

feedback about motion efficiency in learning new surgical skills.

Am J Surg 193(1):105–110

16. Nousiainen M, Brydges R, Backstein D, Dubrowski A (2008)

Comparison of expert instruction and computer-based video

training in teaching fundamental surgical skills to medical stu-

dents. Surgery 143(4):539–544

17. Mann KV, Sutton E, Frank B (2007) Twelve tips for preparing

residents as teachers. Med Teach 29(4):301–306

18. Kim MJ, Boehler ML, Ketchum JK, Bueno R Jr, Williams RG,

Dunnington GL (2010) Skills coaches as part of the educational

team: a randomized controlled trial of teaching of a basic surgical

skill in the laboratory setting. Am J Surg 199(1):94–98

Updates Surg (2013) 65:131–140 139

123

Page 10: Acquisition of suture skills during medical graduation by instructor-directed training: a randomized controlled study comparing senior medical students and faculty surgeons

19. Rooney DM, Hungness ES, Darosa DA, Pugh CM (2012) Can

skills coaches be used to assess resident performance in the skills

laboratory? Surgery 151(6):796–802

20. Wadoodi A, Crosby JR (2002) Twelve tips for peer-assisted

learning: a classic concept revisited. Med Teach 24(3):241–244

21. Graziano SC (2011) Randomized surgical training for medical

students: resident versus peer-led teaching. Am J Obstet Gynecol

204(6):542.e1–542.e4

22. Field M, Burke JM, McAllister D, Lloyd DM (2007) Peer-

assisted learning: a novel approach to clinical skills learning for

medical students. Med Educ 41(4):411–418

23. Josephson SA, Whelan AJ (2002) A new first-year course

designed and taught by a senior medical student. Acad Med

77(12 Pt 1):1207–1211

24. Tolsgaard MG, Gustafsson A, Rasmussen MB, Høiby P, Muller

CG, Ringsted C (2007) Student teachers can be as good as

associate professors in teaching clinical skills. Med Teach

29(6):553–557

25. Weyrich P, Celebi N, Schrauth M, Moltner A, Lammerding-

Koppel M, Nikendei C (2009) Peer-assisted versus faculty staff-

led skills laboratory training: a randomised controlled trial. Med

Educ 43(2):113–120

26. Hughes TC, Jiwaji Z, Lally K, Lloyd-Lavery A, Lota A, Dale A,

Janas R, Bulstrode CJ (2010) Advanced cardiac resuscitation

evaluation (ACRE): a randomised single-blind controlled trial of

peer-led vs. expert-led advanced resuscitation training. Scand J

Trauma Resusc Emerg Med 18:3

27. Knobe M, Munker R, Sellei RM, Holschen M, Mooij SC,

Schmidt-Rohlfing B, Niethard FU, Pape HC (2010) Peer teach-

ing: a randomised controlled trial using student-teachers to teach

musculoskeletal ultrasound. Med Educ 44(2):148–155

28. Janis JE, Kwon RK, Lalonde DH (2010) A practical guide to

wound healing. Plast Reconstr Surg 125(6):230e–244e

29. Sobral DT (2002) Cross-year peer tutoring experience in a

medical school: conditions and outcomes for student tutors. Med

Educ 36(11):1064–1070

30. Khan MS, Bann SD, Darzi A, Butler PE (2003) Use of suturing as

a measure of technical competence. Ann Plast Surg 50(3):

304–308

31. Collins AM, Ridgway PF, Hassan MS, Chou CW, Hill AD,

Kneafsey B (2010) Surgical instruction for general practitioners:

how, who and how often? J Plast Reconstr Aesthet Surg

63(7):1156–1162

32. Faulkner H, Regehr G, Martin J, Reznick R (1996) Validation of

an objective structured assessment of technical skill for surgical

residents. Acad Med 71(12):1363–1365

33. Reznick R, Regehr G, MacRae H, Martin J, McCulloch W (1997)

Testing technical skill via an innovative ‘‘bench station’’ exam-

ination. Am J Surg 173(3):226–230

34. Hojat M, Xu G (2004) A visitor’s guide to effect sizes: statistical

significance versus practical (clinical) importance of research

findings. Adv Health Sci Educ Theory Pract 9:241–249

35. Moulton CA, Dubrowski A, Macrae H, Graham B, Grober E,

Reznick R (2006) Teaching surgical skills: what kind of practice

makes perfect?: a randomized, controlled trial. Ann Surg

244(3):400–409

36. Klingensmith ME, Brunt LM (2010) Focused surgical skills

training for senior medical students and interns. Surg Clin North

Am 90(3):505–518

37. Rogers DA, Regehr G, Yeh KA, Howdieshell TR (1998) Com-

puter-assisted learning versus a lecture and feedback seminar for

teaching a basic surgical technical skill. Am J Surg 175(6):

508–510

38. Mitchell EL, Lee DY, Sevdalis N, Partsafas AW, Landry GJ,

Liem TK, Moneta GL (2011) Evaluation of distributed practice

schedules on retention of a newly acquired surgical skill: a ran-

domized trial. Am J Surg 201(1):31–39

39. Jamshidi R, Ozgediz D (2008) Medical student teaching: a peer-

to-peer toolbox for time-constrained resident educators. J Surg

Educ 65(2):95–98

40. Vassiliou MC, Feldman LS (2011) Objective assessment, selec-

tion, and certification in surgery. Surg Oncol 20(3):140–145

41. Darzi A, Datta V, Mackay S (2001) The challenge of objective

assessment of surgical skill. Am J Surg 181(6):484–486

42. van Hove PD, Tuijthof GJ, Verdaasdonk EG, Stassen LP,

Dankelman J (2010) Objective assessment of technical surgical

skills. Br J Surg 97(7):972–987

43. Dath D, Regehr G, Birch D, Schlachta C, Poulin E, Mamazza J,

Reznick R, MacRae HM (2004) Toward reliable operative

assessment: the reliability and feasibility of videotaped assess-

ment of laparoscopic technical skills. Surg Endosc 18(12):1800–

1804

44. Bing-You RG, Sproul MS (1992) Medical students’ perceptions

of themselves and residents as teachers. Med Teach 14(2–3):

133–138

140 Updates Surg (2013) 65:131–140

123