Original Study

The Effects of Local Low-Dose Heat Application on Dysmenorrhea

Dilek Coskuner Potur PhD, RN *, Nuran K€om€urc€u PhD, RNFaculty of Health Sciences, Division of Nursing, Department of Obstetrics and Gynecology Nursing, Marmara University, Istanbul, Turkey

a b s t r a c t

Objectives: This is a controlled, prospective study which compares th

e effects of a low-dose heat patch for self-medication on the reductionof pain symptoms in dysmenorrhea.Methods: The sample group included female sophomore students studying at a university in Istanbul, Turkey, between 2007 and 2008.These female participants completed the Dysmenorrhea Identification Form to determine the sample group, and a total of 193 femalestudents possessed the eligible criteria. The research control group consisted of 66 patients, the analgesia group consisted of 61, and theheat patch group consisted of 66. The control group did not use any treatments, while the self-medication group used analgesic medication(single dose), and the heat patch group applied a heat patch on the lower abdomen, against the skin, for an application period of 2menstrual cycles. Using a visual analog scale (VAS), the pain severity was recorded at the baseline, after 4 hours of intervention, and after 8hours of intervention. The data were examined using ANOVA.Results: There were significant differences between the groups in terms of pain severity after 8 hours of application (P ! .001). All groupshad similar pain levels at baseline and during the fourth and eighth hours, with no significant differences between the groups during thefirst and the second menstrual cycles (P O .05).Conclusion: The authors conclude that the heat patch is an effective method for reducing dysmenorrhea.Key Words: Analgesic, Dysmenorrhea, Heat application, Menstrual cycle, Pain severity

Introduction

Dysmenorrhea, a term rooted in ancient Greek thatmeans ‘difficult menstrual flow’ or ‘painful menstruation,’is one of the most common gynecologic symptoms reportedby women.1e3 Traditionally, dysmenorrhea is classified into2 categories. Primary dysmenorrhea is menstrual painoccurring in the absence of any pelvic diseases; secondarydysmenorrhea, on the other hand, is associated withan underlying pathology, such as pelvic inflammatorydisease.4e9

The prevalence of dysmenorrhea varies greatly between45.3%-90% depending on methods of data collection, agiven study’s definition of dysmenorrhea, and studypopulation.1,2,9e17

Morbidity due to dysmenorrhea represents a substantialpublic health burden; it is the single greatest cause oflost working hours and failure to attend school in adoles-cent girls.18e20 Dysmenorrhea has been estimated toaccount for 600 million lost work hours and $2 billion inlost productivity annually in the United States alone.21,22

The authors indicate no conflicts of interest.Our research was presented at the first International Congress on Nursing Edu-

cation, Research, and Practise, 15-17 October 2009, Thessaloniki. This study wassupported by Marmara University Scientific Research Project Commission (SA�G-DKR-120707-0148). We confirm that our manuscript complies with the standarts ofethical research. We declare no conflict of interest.* Address correspondence to: Dilek Coskuner Potur, PhD, RN, Marmara University

Faculty of Health Sciences, Division of Nursing, Department of Obstetrics andGynecology Nursing, Tıbbiye Cad No:40 Haydarpasa, _Istanbul, Turkey 34668;Phone: þ90 216 330 20 70- 1141; fax: þ90 216 418 37 73

E-mail address: dilekcp@yahoo.com (D.C. Potur).

1083-3188/$ - see front matter � 2013 North American Society for Pediatric and Adoleshttp://dx.doi.org/10.1016/j.jpag.2013.11.003

However, there are no studies investigating the effects ofdysmenorrhea on economic life in Turkey.

Despite continuous advances in the understanding ofthe pathophysiology and treatment of dysmenorrhea, manywomen continue to suffer from dysmenorrhea everymonth. Studies have shown that only a small group ofyoung women with dysmenorrhea consult physicians(19.3%-28%), and that the use of over-the-counter/selfmedication (35.1%- 60.9%) is common practice amongadolescents.1,13

Current treatments for dysmenorrhea include bed rest,23

exercise,24 spinal manipulation,25 aroma therapy,26,27 nu-trition,6 massage,26 transcutaneous electrical nerve sti-mulation (TENS),28,29 acupuncture,7 acupressure,19e21,30

yoga,31 and analgesic medication.23

Another treatment method, the use of heat in differentforms (such as a hot bag, a towel, or a bottle), has tradi-tionally been used to ease menstrual pain in many cultures,and has a long history in common use and folklore. Studieshave found that the use of heat is a common (36.5%-50%)method for coping with dysmenorrhea.1,11,23 Although theuse of heat is one of the oldest treatment methods fordysmenorrhea, it has been abandoned due to the increasedpossibility of acute inflammation. However, the method hasbeen adapted to the modern age and medical companieshave produced heat bandages. Heat increases the bloodflow in the area of application via vasodilatation, leading torelaxation of smoothmuscle and decrease in the perceptionof pain. Unfortunately, this therapy lacks rigorous or sys-tematic evaluation in the scientific literature, and only a fewcase reports are available. The recent development of small

cent Gynecology. Published by Elsevier Inc.

Fig. 1. Randomization scheme.Ă

D.C. Potur, N. K€om€urc€u / J Pediatr Adolesc Gynecol xxx (2013) 1e62

wearable devices capable of supplying a low level of topicalheat at a constant temperature over an 8-hour periodmakes this modality portable enough to be a viable treat-ment option.32

Prior to conducting our study, we reviewed 2 priorstudies that investigated the efficacy of heat application inrelieving dysmenorrhea. These studies did not monitor 2separate menstrual cycles.32,33 Use of over-the-counter/selfmedication has been reported to be quite extensive in theliterature for the relief of dysmenorrhea.10,13,14 Therefore, inorder to determine the effectiveness of local low-dose heatapplication, a comparison group of participants who usedover-the-counter/self medication to manage the symptomsof dysmenorrheawas included in the study. A control groupis useful in detecting the spontaneous disappearance ofpain and other symptoms. No specific studies existed in theliterature investigating the efficacy of heat application as ageneral nursing practice in relieving dysmenorrhea.

Methods

Study Design

A prospective experimental design using 3 groups(control group, self-medication group, heat patch group)was conducted from October 2007 until March 2008 in astate university in Istanbul, Turkey.

Setting and Samples

The study sample included female sophomore studentsat the School of Education and the School of Arts andSciences. The inclusion criteria included subjects betweenthe ages of 18-24 years old, who were nulliparous; had ahistory of regular menstrual cycles (during the last6 months) accompanied by moderate to severe pain (ie,score of 5 or more on the visual analog scale (VAS); did notuse hormonal contraceptives; and did not have a systemicor chronic disease (ie, diabetes, poor circulation or heartdisease, rheumatoid arthritis).

Subjects who had cutaneous lesions involving theabdominal wall, had used a heat patch previous to thestudy, used complementary and alternative therapiesduring the study period, experienced menstrual irregular-ities, or had infectious diseases involving fever wereexcluded from the study. However, the heat patch groupand the control group were advised not to take analgesicsduring the study period.

A power analysis was used to determine the sample sizebefore the investigation. The average pain severity scorewas extrapolated to be 1.51; therefore, a minimum of 50participants per group was necessary to achieve a power of81% (1-ß) with an alpha of .05.

Among the 906 students who completed the Dysmen-orrhea Identification Form (DIF), 421 met the inclusioncriteria for our study, and 252 female students from amongthis group were willing to participate. All participants whomet the inclusion criteria were listed randomly. The par-ticipants were balloted and the first rank was determinedas the control group (CG), the second rank was determinedas the self-medication group (SMG), and the third rank wasdetermined as the local low-dose heat patch group (HPG).The randomization scheme is summarized in Fig. 1.

Some participants discontinued the study during the2-month follow-up period. The algorithm in Fig. 2 illus-trates the reasons for these discontinuations.

Data Collection Tools

The data collection tools were prepared according tothe researchers’ knowledge of the literature.

Dysmenorrhea Identification FormThis form was used to determine the study sample.

Students who volunteered to complete the DIF and who haddysmenorrheal pain were included in the study. The ques-tions included in the DIF were prepared in order to pre-define potential factors related to the study design orpopulation that may affect the study, and to excludeindividuals with qualities related to these factors. The DIF,which consists of 25 questions related to age, marital status,the use of contraceptives, menstrual history during theprevious 6 months, menstrual irregularity, dysfunctionaluterine bleeding, dysmenorrheal pain severity, othergynecologic problems, and systemic and chronic diseases,took approximately 15 to 20 minutes to complete. Theresearcher answered the participants’ questions regardingthe DIF during its administration. A pilot study, including 10female students, was conducted to establish whether thestudents could understand and respond appropriately tothe questions.

Data Collection Form (DCF)The DCF included data regarding the descriptive char-

acteristics of the students (age, weight, height, body massindex) and the age at menarche.

Visual Analog ScaleMany of the reviewed studies evaluated dysmenorrheal

pain measured using VAS as an end point.7,26,29 The VASconsists of a 0-10 cm vertical scale with the descriptors “nopain” on the bottom (at 0 cm) and “worst possible pain” onthe top (at 10 cm).34,35 Participants were asked to place amark on the 10-cm line at a point that corresponded to thelevel of pain severity they felt.

Fig. 2. Flow diagram of participant progress.Ă

D.C. Potur, N. K€om€urc€u / J Pediatr Adolesc Gynecol xxx (2013) 1e6 3

Dysmenorrhea Monitoring Form (DMF)The DMF is a prospective measure of pain severity,

disability, and medication use. Efficacy was measuredthrough the changes in the baseline scores (pain reduction)of pain severity. Pain severity was recorded by the partici-pants on the VAS in the DMF at 3 different points in time:baseline (T1), after 4 hours of the intervention (mid-treat-ment, T2), and after 8 hours of the intervention (end oftreatment, T3). Individuals in all groups recorded theirbaseline pain severity levels before receiving treatment.The control group did not receive any interventions aftermarking the initial levels of pain. The SMG used analgesicsand the HPG used the heat patch. All groups marked theseverity of the pain they felt at the fourth and eighth hoursof the intervention. The DMF form was used during 2menstrual cycles.

The control group did not receive any interventionsfor dysmenorrheal pain. The participants in the CG weretold that they could use a method for pain reduction if their

pain became unbearable, and that they must describe thesemethods of pain reduction on the DMF. The participantswere also told that they would be excluded from the studyif they used pain reduction methods for dysmenorrhea.The participants in the SMG were told to take analgesicdrugs (single dose) of their own choice during the studyperiod. Since nurses cannot prescribe drugs in Turkey, over-the-counter drugs were recommended. The participantsin the self-medication group were asked to record their useof extra doses of analgesics or use of other methods on theDMF. They were also told that they would be excluded fromthe study if they used more than a single dose or other painreduction methods. Heat patches were applied on the lowerabdomen (directly on the skin) in the HPG. Similarly, theparticipants in the HPG were asked to record their useof analgesics or other pain reduction methods on the DMF.In cases where they did not use the heat patch, they weretold to provide this information on the DMF as well. Theywere told that they would be excluded from the study

Table 2Comparison of First and Second Menstrual Cycles Pain Intensities of the FemaleStudents (N 5 193)

Period Groups CG(n 5 66)

SMG(n 5 61)

HPG(n 5 66)

StatisticalAnalysis*

Mean � SD Mean � SD Mean � SD F P

FirstMenstrualCycle

T1 7.34 � 1.36 8.09 � 1.33 8.08 � 1.24 7.06 !.001*T2 6.58 � 1.66 5.21 � 2.60 4.76 � 2.29 4.44 !.001y

T3 5.78 � 2.63 4.19 � 3.03 1.99 � 2.42Second

MenstrualCycle

T1 7.50 � 1.48 8.07 � 1.26 8.04 � 1.35 3.54 O.05*T2 6.90 � 1.53 5.79 � 2.45 4.53 � 2.39 10.90 !.001y

T3 5.94 � 2.51 3.61 � 3.08 1.90 � 2.39

SD, Standard deviation; T1, Baseline; T2, Mid treatment; T3, End of treatment.* Assessed through 1-way ANOVA.y Assessed through repeated ANOVA according to the baseline pain intensities.

Table 1Demographic Data of Participants (N 5 193)

Variables Groups (n) Weight (kg)Mean � SD

P*

Age (y) CG (66) 19.76 � 1.22 F 5 .652O.05SMG (61) 19.92 � 1.06

HPG (66) 19.94 � 1.35Weight (kg) CG (66) 58.13 � 6.44 F 5 2.13

O.05SMG (61) 55.85 � 8.23HPG (66) 55.92 � 6.78

Height (cm) CG (66) 165.07 � 5.28 F 5 .39O.05SMG (61) 164.21 � 6.65

HPG (66) 164.90 � 5.34BMI (kg/m2) CG (66) 21.36 � 2.24 F 5 2.004

O.05SMG (61) 2.70 � 2.67HPG (66) 2.57 � 2.36

Menarche age (y) CG (66) 13.18 � 1.06 F 5 .33O.05SMG (61) 12.32 � 1.13

HPG (66) 13.15 � 1.05

SD, Standard deviation.* Assessed through 1-way ANOVA.

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if they used a pain reduction method other than heatpatches, or if they did not use the heat patches. The appli-cation period included 2 menstrual cycles.

Intervention

The heat patch contains natural components includingiron, coal, water, and salt. These components become warmand give off heat when they interact with the air. Heatincreases the blood flow to the area of application viavasodilatation, leading to smooth muscle relaxation and adecrease in the perception of pain. The heat patch suppliedheat at a constant temperature of approximately 38.9�C(102.02�F) over a surface area of 180 cm2. It may take up to30 minutes to reach therapeutic temperature. This devicewas capable of supplying warmth for the complete durationof the 8-hour study period.32,33 The positioning of theabdominal patch on the lower abdomen was standardized,and the patch was held in place by adhering it to theparticipant’s underwear, which completely covered thepatch while it was in position. The participants were giveninformation and a form about the heat patch, and the heatpatches were applied on the first day of menstruation for 8hours, during 2 menstrual cycles in the HPG.

Data Analysis

Data analyses were carried out using the StatisticalSoftware Package for the Social Science, version 15.0 (SPSSInc, Chicago, IL). All data were examined with analysis ofvariance (ANOVA) and repeated ANOVA. The acceptedconfidence interval was 95% and the significance level for allanalyses was P ! .05.

Ethical Considerations

In all stages of the study, ethical principles were carefullytaken into consideration. Recruited participants in the3 groups received a written description of the purposes ofthe research and gave written notified consent after theprocedures had been fully explained. In addition, the stu-dents signed consent forms and were told that they couldwithdraw from the study at any time (especially when theycould not tolerate the pain) during the data collectionperiod. Permission to conduct the study and access to thefemale students were obtained from the dean of the Schoolsof Education, Arts and Sciences. The study was approved bythe Ethics Committee of Marmara University in Istanbul(date: 08.06.2007 and number: B.30.2.MAR.0.01.02/AEK/1029). We ran the study according to Helsinki Declaration(as revised in Edinburgh 2000).

Results

Demographic data statistics of the participant are pre-sented in Table 1. There were no significant differencesbetween the CG, the SMG, and the HPG regarding age,weight, height, BMI, and age at menarche (Table 1, PO .05).

The mean T1 pain severity of the participants was foundto be 7.34 � 1.36 in the CG, 8.09 � 1.33 in the SMG and8.08 � 1.24 in the HPG during the first menstrual cycle

([FMC], Table 2). T1 pain severity levels were lower in theCG than in the SMG (0.75þ 0.03) or in the HPG (0.74þ 0.12),a difference that was statistically significant for the CG vsboth of the other groups (F: 7.06, P ! .001, Table 2).

The pain reduction methods were applied to the groupsfollowing T1 pain measurement. Pain severity at the T2following intervention was 6.58 � 1.66 in the CG, 5.21 �2.60 in the SMG, and 4.76 � 2.29 in the HPG. The CGreported that they experienced more pain than the SMG(1.37 � �0.94) and the HPG (1.82 � �0.63), whereas theSMG reported that they experienced more pain than theHPG (0.45 � 0.31). There were significant differencesbetween the 3 groups in the terms of pain severity at the T2of the intervention (P ! .001, Table 2). At the T3 of theintervention, pain severity was determined to be 5.78 �2.63 in the CG, 4.19� 3.03 in the SMG, and 1.99� 2.42 in theHPG. Individuals in the CG experienced more pain thanthose in the SMG (1.59 � �0.4) and the HPG (3.79 � 0.21);those in the SMG reported more pain than those in the HPG(2.20 � 0.61). There was a significant difference betweenthe 3 groups at the T3 of the intervention in terms of painseverity. The pain severity of the HPG decreased signifi-cantly at the end of the intervention the FMC (P ! .001,Table 2).

The mean T1 pain severity of the participants was foundto be 7.50 � 1.48 in the CG, 8.07 � 1.26 in the SMG, and8.04 � 1.35 in the HPG during the second menstrual cycle

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(SMC) There was no significant difference betweenthe groups in terms of the initial pain levels during the SMC(P ! .05, Table 2).

The pain reduction methods were applied to the groupsfollowing T1 pain measurement. There was a significantdifference between the 3 groups in the terms of painseverity at the T2 of the intervention (P ! .001, Table 2).There was a significant difference between the 3 groups atthe T3 of the intervention in terms of pain severity. The painseverity of the HPG decreased significantly at the end of theintervention the SMC (P ! .001, Table 2).

All groups had similar pain levels at T1 and during the T2and T3, with no significant differences between the groupsduring the first and the second menstrual cycles (P O .05,Table 2).

Discussion

This study investigated the effectiveness of local low-dose heat application on reducing dysmenorrheal pain.The 3 groups were allocated randomly and had no apparentdifferences in their characteristics. The results indicatedthat the heat patch was significantly effective in alleviatingdysmenorrhea.

When we compared the mean baseline pain levels inour study with international studies investigating theseverity of dysmenorrheal pain through the VAS, weobserved that the results of our study are similar to those ofIorno et al7 and Abbaspour et al.24 However, Chen andChen,21 Jun et al,30 and Akin et al32,33 have reported higherinitial pain levels compared to the results of other studies.This inconsistency may have resulted from recruiting par-ticipants who had pain levels of 5 or above.

During the 2 menstrual cycles, the participants usedanalgesics or heat patches after recording their pain levels.The pain severity at T2 of the intervention, during bothmenstrual cycles in all groups, was moderate according tothe classification by Kaplan et al.29

The results of Chen and Chen21 (acupressure) and Kaba28

(TENS), who used different interventional methods in theirstudies, are similar to our results regarding the pain levels atthe end of the treatment.

In a study by Akin et al,32 investigating the effectivenessof heat patches and acetaminophen in relieving dysmen-orrhea, the pain severity during the first day of menstrua-tion was evaluated through 8 hours. This study found thatpain levels in the heat-patch group significantly decreasedcompared to those in the acetaminophen group, after 1.5hours of treatment, and that a significant difference existedbetween the groups regarding the pain levels at the 3rd, 4th,5th, and 6th hours of the intervention (P ! .05).

In a study by Akin et al,33 investigating the effectivenessof heat patches and ibuprofen in relieving dysmenorrhea,the pain severity during 2 days of menstruation was eval-uated through 12 hours. The pain reduction in the heatpatch plus ibuprofen group and the placebo patch plusibuprofen group was similar during the 2 days (P5 .096). Inaddition, a significant difference existed between thegroups regarding the pain levels at the third and fourthhours of the intervention. It was also determined that the

heat patch plus ibuprofen group experienced a more rapiddecline in pain levels compared to the ibuprofen group. Thecomparisons between the placebo heat patch, the placeboibuprofen, and the heat patch plus ibuprofen groups, withregard to pain levels, showed that the placebo groupexperienced more pain. According to the results of thestudy, heat patch therapy is 4 times more effective than theunheated patch and placebo in relieving dysmenorrhea.This result indicates that heat patches would be moreeffective if they were used in combination with analgesics.

Our results regarding the efficacy of heat patches inrelieving dysmenorrhea are similar to those of Akinet al.32,33

A comparison between the pain levels of the groupsduring the 2 menstrual cycles showed no significantdifferences between the 3 groups with respect to T1 painlevels and pain severity at the T2 and T3 hours of theintervention. This finding indicates the accuracy of ourstudy.

Limitations

We are well aware of the limitations of the presentstudy. Firstly, the results of this study cannot be generalizeddue to a lack of random assignment of participants;furthermore, individuals with chronic and systemic dis-eases cannot use the heat patch. Secondly, the subjects werenot blinded to the treatments, because fully masking thetreatments (heat application, analgesic, and control) wasimpossible owing to the present study’s design. Thirdly,although we planned to establish a placebo group in thestudy, the fact that the low-dose heat patches are manu-factured abroad makes it impossible to manufactureplacebo patches within our country for use in our study.Finally, we sampled only the university students and theymay be different from the level of education different fe-male group. Future research should be conducted withplacebo group and level of education different women.

Conclusions

Local low-dose heat application, an easily applied andnoninvasive method, can be recommended by nurses torelieve menstrual pain. Unlike acupressure, acupuncture,spinal manipulation, TENS, etc, the use of heat patches doesnot require special equipment, nor does it require applica-tion by an expert in a clinical setting. Therefore, heatpatches have economic advantages as well as being time-efficient. In addition, the participants in our study re-ported that they were satisfied with the heat patches, and itcan be assumed that working women and other femalestudents may also benefit from the heat patches. Heatpatches seem to be an effective method for coping withdysmenorrheal pain; therefore, the use of heat patches mayhave a positive effect on women’s social lives duringmenstruation.

Another group that may benefit is teens and womenwhocannot use analgesics due to their side effects, because heatpatches do not have these side effects. However, who canuse analgesics can use a combination of heat patches and

D.C. Potur, N. K€om€urc€u / J Pediatr Adolesc Gynecol xxx (2013) 1e66

analgesics. In conclusion, heat patches are a beneficialproduct for improving women’s health. In the future, ran-domized placebo-controlled studies should be conducted inorder to determine the efficacy of heat patches in thereduction of dysmenorrheal pain.

Acknowledgment

We wish to thank all the subjects who so willinglyparticipated in this study. We also wish to acknowledge ourstatistics expert Assis Prof Dr €Omer Uysal. This study wassupported by Marmara University Scientific Research Proj-ect Commission (SA�G-DKR-120707-0148). Presented at the1st International Congress On Nursing Education, Research& Practise, 15-17 October 2009, Thessaloniki, Greece Inter-national Journal of Caring Sciences Vol:2 Supplement:1.

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