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Introduction

Dysmenorrhea, a term rooted in ancient Greek that means ‘difficult menstrual flow’ or ‘painful menstruation,’ is one of the most common gynecologic symptoms reported by women. 1, 2 and 3 Traditionally, dysmenorrhea is classified into 2 categories. Primary dysmenorrhea is menstrual pain occurring in the absence of any pelvic diseases; secondary dysmenorrhea, on the other hand, is associated with an underlying pathology, such as pelvic inflammatory disease. 4, 5, 6, 7, 8 and 9

 

The prevalence of dysmenorrhea varies greatly between 45.3%-90% depending on methods of data collection, a given study’s definition of dysmenorrhea, and study population.1, 2, 9, 10, 11, 12, 13, 14, 15, 16 and 17

 

Morbidity due to dysmenorrhea represents a substantial public health burden; it is the single greatest cause of lost working hours and failure to attend school in adolescent girls.18, 19 and 20 Dysmenorrhea has been estimated to account for 600 million lost work hours and $2 billion in lost productivity annually in the United States alone.21 and 22 However, there are no studies investigating the effects of dysmenorrhea on economic life in Turkey.

 

Despite continuous advances in the understanding of the pathophysiology and treatment of dysmenorrhea, many women continue to suffer from dysmenorrhea every month. Studies have shown that only a small group of young women with dysmenorrhea consult physicians (19.3%-28%), and that the use of over-the-counter/self medication (35.1%-60.9%) is common practice among adolescents.1 and 13

 

Current treatments for dysmenorrhea include bed rest,23 exercise,24 spinal manipulation,25 aroma therapy,26 and 27 nutrition,6 massage,26 transcutaneous electrical nerve stimulation (TENS),28 and 29 acupuncture,7 acupressure,19, 20, 21 and 30 yoga,31 and analgesic medication.23

 

Another treatment method, the use of heat in different forms (such as a hot bag, a towel, or a bottle), has traditionally been used to ease menstrual pain in many cultures, and has a long history in common use and folklore. Studies have found that the use of heat is a common (36.5%-50%) method for coping with dysmenorrhea.1, 11 and 23 Although the use of heat is one of the oldest treatment methods for dysmenorrhea, it has been abandoned due to the increased possibility of acute inflammation. However, the method has been adapted to the modern age and medical companies have produced heat bandages. Heat increases the blood flow in the area of application via vasodilatation, leading to relaxation of smooth muscle and decrease in the perception of pain. Unfortunately, this therapy lacks rigorous or systematic evaluation in the scientific literature, and only a few case reports are available. The recent development of small wearable devices capable of supplying a low level of topical heat at a constant temperature over an 8-hour period makes this modality portable enough to be a viable treatment option.32

 

Prior to conducting our study, we reviewed 2 prior studies that investigated the efficacy of heat application in relieving dysmenorrhea. These studies did not monitor 2 separate menstrual cycles.32 and 33 Use of over-the-counter/self medication has been reported to be quite extensive in the literature for the relief of dysmenorrhea.10, 13 and 14 Therefore, in order to determine the effectiveness of local low-dose heat application, a comparison group of participants who used over-the-counter/self medication to manage the symptoms of dysmenorrhea was included in the study. A control group is useful in detecting the spontaneous disappearance of pain and other symptoms. No specific studies existed in the literature investigating the efficacy of heat application as a general 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 a state university in Istanbul, Turkey.

 

Setting and Samples

The study sample included female sophomore students at the School of Education and the School of Arts and Sciences. The inclusion criteria included subjects between the ages of 18-24 years old, who were nulliparous; had a history of regular menstrual cycles (during the last 6 months) accompanied by moderate to severe pain (ie, score of 5 or more on the visual analog scale (VAS); did not use hormonal contraceptives; and did not have a systemic or chronic disease (ie, diabetes, poor circulation or heart disease, rheumatoid arthritis).

 

Subjects who had cutaneous lesions involving the abdominal wall, had used a heat patch previous to the study, used complementary and alternative therapies during the study period, experienced menstrual irregularities, or had infectious diseases involving fever were excluded from the study. However, the heat patch group and the control group were advised not to take analgesics during the study period.

 

A power analysis was used to determine the sample size before the investigation. The average pain severity score was extrapolated to be 1.51; therefore, a minimum of 50 participants per group was necessary to achieve a power of 81% (1-ß) with an alpha of .05.

 

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

 

 

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

 

 

Data Collection Tools

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

 

Dysmenorrhea Identification Form

This form was used to determine the study sample. Students who volunteered to complete the DIF and who had dysmenorrheal pain were included in the study. The questions included in the DIF were prepared in order to predefine potential factors related to the study design or population that may affect the study, and to exclude individuals 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 the previous 6 months, menstrual irregularity, dysfunctional uterine bleeding, dysmenorrheal pain severity, other gynecologic problems, and systemic and chronic diseases, took approximately 15 to 20 minutes to complete. The researcher answered the participants’ questions regarding the DIF during its administration. A pilot study, including 10 female students, was conducted to establish whether the students could understand and respond appropriately to the questions.

 

Data Collection Form (DCF)

The DCF included data regarding the descriptive characteristics of the students (age, weight, height, body mass index) and the age at menarche.

 

Visual Analog Scale

Many of the reviewed studies evaluated dysmenorrheal pain measured using VAS as an end point.7, 26 and 29 The VAS consists of a 0-10 cm vertical scale with the descriptors “no pain” on the bottom (at 0 cm) and “worst possible pain” on the top (at 10 cm).34 and 35 Participants were asked to place a mark on the 10-cm line at a point that corresponded to the level of pain severity they felt.

 

Dysmenorrhea Monitoring Form (DMF)

The DMF is a prospective measure of pain severity, disability, and medication use. Efficacy was measured through the changes in the baseline scores (pain reduction) of pain severity. Pain severity was recorded by the participants on the VAS in the DMF at 3 different points in time: baseline (T1), after 4 hours of the intervention (mid-treatment, T2), and after 8 hours of the intervention (end of treatment, T3). Individuals in all groups recorded their baseline pain severity levels before receiving treatment. The control group did not receive any interventions after marking the initial levels of pain. The SMG used analgesics and the HPG used the heat patch. All groups marked the severity of the pain they felt at the fourth and eighth hours of the intervention. The DMF form was used during 2 menstrual cycles.

 

The control group did not receive any interventions for dysmenorrheal pain. The participants in the CG were told that they could use a method for pain reduction if their pain became unbearable, and that they must describe these methods of pain reduction on the DMF. The participants were also told that they would be excluded from the study if they used pain reduction methods for dysmenorrhea. The participants in the SMG were told to take analgesic drugs (single dose) of their own choice during the study period. Since nurses cannot prescribe drugs in Turkey, over-the-counter drugs were recommended. The participants in the self-medication group were asked to record their use of extra doses of analgesics or use of other methods on the DMF. They were also told that they would be excluded from the study if they used more than a single dose or other pain reduction methods. Heat patches were applied on the lower abdomen (directly on the skin) in the HPG. Similarly, the participants in the HPG were asked to record their use of analgesics or other pain reduction methods on the DMF. In cases where they did not use the heat patch, they were told to provide this information on the DMF as well. They were told that they would be excluded from the study if they used a pain reduction method other than heat patches, or if they did not use the heat patches. The application period included 2 menstrual cycles.

 

Intervention

The heat patch contains natural components including iron, coal, water, and salt. These components become warm and give off heat when they interact with the air. Heat increases the blood flow to the area of application via vasodilatation, leading to smooth muscle relaxation and a decrease in the perception of pain. The heat patch supplied heat at a constant temperature of approximately 38.9°C (102.02°F) over a surface area of 180 cm2. It may take up to 30 minutes to reach therapeutic temperature. This device was capable of supplying warmth for the complete duration of the 8-hour study period.32 and 33 The positioning of the abdominal patch on the lower abdomen was standardized, and the patch was held in place by adhering it to the participant’s underwear, which completely covered the patch while it was in position. The participants were given information and a form about the heat patch, and the heat patches were applied on the first day of menstruation for 8 hours, during 2 menstrual cycles in the HPG.

 

Data Analysis

Data analyses were carried out using the Statistical Software Package for the Social Science, version 15.0 (SPSS Inc, Chicago, IL). All data were examined with analysis of variance (ANOVA) and repeated ANOVA. The accepted confidence interval was 95% and the significance level for all analyses was P < .05.

 

Ethical Considerations

In all stages of the study, ethical principles were carefully taken into consideration. Recruited participants in the 3 groups received a written description of the purposes of the research and gave written notified consent after the procedures had been fully explained. In addition, the students signed consent forms and were told that they could withdraw from the study at any time (especially when they could not tolerate the pain) during the data collection period. Permission to conduct the study and access to the female students were obtained from the dean of the Schools of Education, Arts and Sciences. The study was approved by the 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 presented in Table 1. There were no significant differences between the CG, the SMG, and the HPG regarding age, weight, height, BMI, and age at menarche (Table 1, P > .05).

 

 

The mean T1 pain severity of the participants was found to be 7.34 ± 1.36 in the CG, 8.09 ± 1.33 in the SMG and 8.08 ± 1.24 in the HPG during the first menstrual cycle ([FMC], Table 2). T1 pain severity levels were lower in the CG than in the SMG (0.75 + 0.03) or in the HPG (0.74 + 0.12), a difference that was statistically significant for the CG vs both of the other groups (F: 7.06, P < .001, Table 2).

 

 

The pain reduction methods were applied to the groups following T1 pain measurement. Pain severity at the T2 following 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 CG reported that they experienced more pain than the SMG (1.37 ± −0.94) and the HPG (1.82 ± −0.63), whereas the SMG reported that they experienced more pain than the HPG (0.45 ± 0.31). There were significant differences between the 3 groups in the terms of pain severity at the T2 of the intervention (P < .001, Table 2). At the T3 of the intervention, 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 the HPG. Individuals in the CG experienced more pain than those 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 between the 3 groups at the T3 of the intervention in terms of pain severity. The pain severity of the HPG decreased significantly at the end of the intervention the FMC (P < .001, Table 2).

 

The mean T1 pain severity of the participants was found to be 7.50 ± 1.48 in the CG, 8.07 ± 1.26 in the SMG, and 8.04 ± 1.35 in the HPG during the second menstrual cycle (SMC) There was no significant difference between the groups in terms of the initial pain levels during the SMC (P < .05, Table 2).

 

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

 

All groups had similar pain levels at T1 and during the T2 and T3, with no significant differences between the groups during the first and the second menstrual cycles (P > .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 apparent differences in their characteristics. The results indicated that the heat patch was significantly effective in alleviating dysmenorrhea.

 

When we compared the mean baseline pain levels in our study with international studies investigating the severity of dysmenorrheal pain through the VAS, we observed that the results of our study are similar to those of Iorno et al7 and Abbaspour et al.24 However, Chen and Chen,21 Jun et al,30 and Akin et al32 and 33 have reported higher initial pain levels compared to the results of other studies. This inconsistency may have resulted from recruiting participants who had pain levels of 5 or above.

 

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

 

The results of Chen and Chen21 (acupressure) and Kaba28 (TENS), who used different interventional methods in their studies, are similar to our results regarding the pain levels at the end of the treatment.

 

In a study by Akin et al,32 investigating the effectiveness of heat patches and acetaminophen in relieving dysmenorrhea, the pain severity during the first day of menstruation was evaluated through 8 hours. This study found that pain levels in the heat-patch group significantly decreased compared to those in the acetaminophen group, after 1.5 hours of treatment, and that a significant difference existed between 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 effectiveness of heat patches and ibuprofen in relieving dysmenorrhea, the pain severity during 2 days of menstruation was evaluated through 12 hours. The pain reduction in the heat patch plus ibuprofen group and the placebo patch plus ibuprofen group was similar during the 2 days (P = .096). In addition, a significant difference existed between the groups regarding the pain levels at the third and fourth hours of the intervention. It was also determined that the heat patch plus ibuprofen group experienced a more rapid decline in pain levels compared to the ibuprofen group. The comparisons between the placebo heat patch, the placebo ibuprofen, and the heat patch plus ibuprofen groups, with regard to pain levels, showed that the placebo group experienced more pain. According to the results of the study, heat patch therapy is 4 times more effective than the unheated patch and placebo in relieving dysmenorrhea. This result indicates that heat patches would be more effective if they were used in combination with analgesics.

 

Our results regarding the efficacy of heat patches in relieving dysmenorrhea are similar to those of Akin et al.32 and 33

 

A comparison between the pain levels of the groups during the 2 menstrual cycles showed no significant differences between the 3 groups with respect to T1 pain levels and pain severity at the T2 and T3 hours of the intervention. This finding indicates the accuracy of our study.

 

Limitations

We are well aware of the limitations of the present study. Firstly, the results of this study cannot be generalized due to a lack of random assignment of participants; furthermore, individuals with chronic and systemic diseases cannot use the heat patch. Secondly, the subjects were not blinded to the treatments, because fully masking the treatments (heat application, analgesic, and control) was impossible owing to the present study’s design. Thirdly, although we planned to establish a placebo group in the study, the fact that the low-dose heat patches are manufactured abroad makes it impossible to manufacture placebo patches within our country for use in our study. Finally, we sampled only the university students and they may be different from the level of education different female group. Future research should be conducted with placebo group and level of education different women.

 

Conclusions

Local low-dose heat application, an easily applied and noninvasive method, can be recommended by nurses to relieve menstrual pain. Unlike acupressure, acupuncture, spinal manipulation, TENS, etc, the use of heat patches does not require special equipment, nor does it require application by an expert in a clinical setting. Therefore, heat patches have economic advantages as well as being time-efficient. In addition, the participants in our study reported that they were satisfied with the heat patches, and it can be assumed that working women and other female students may also benefit from the heat patches. Heat patches seem to be an effective method for coping with dysmenorrheal pain; therefore, the use of heat patches may have a positive effect on women’s social lives during menstruation.

 

Another group that may benefit is teens and women who cannot use analgesics due to their side effects, because heat patches do not have these side effects. However, who can use analgesics can use a combination of heat patches and analgesics. In conclusion, heat patches are a beneficial product for improving women’s health. In the future, randomized placebo-controlled studies should be conducted in order to determine the efficacy of heat patches in the reduction of dysmenorrheal pain.

 

Acknowledgment

We wish to thank all the subjects who so willingly participated in this study. We also wish to acknowledge our statistics expert Assis Prof Dr Ömer Uysal. This study was supported by Marmara University Scientific Research Project Commission (SAĞ-DKR-120707-0148). Presented at the 1st International Congress On Nursing Education, Research & Practise, 15-17 October 2009, Thessaloniki, Greece International Journal of Caring Sciences Vol:2 Supplement:1.