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Vol. 36, 2014 DOI: 10.1093/epirev/mxt009 Advance Access publication: November 26, 2013
The Prevalence and Risk Factors of Dysmenorrhea
Hong Ju*, Mark Jones, and Gita Mishra * Correspondence to Hong Ju, Centre for Longitudinal and Life Course Research, School of Population Health, University of Queensland, Herston Road, Herston, QLD 4006, Australia (e-mail: [email protected]).
Dysmenorrhea is a common menstrual complaint with a major impact on women’s quality of life, work productivity, and health-care utilization. A comprehensive review was performed on longitudinal or case-control or crosssectional studies with large community-based samples to accurately determine the prevalence and/or incidence and risk factors of dysmenorrhea. Fifteen primary studies, published between 2002 and 2011, met the inclusion criteria. The prevalence of dysmenorrhea varies between 16% and 91% in women of reproductive age, with severe pain in 2%–29% of the women studied. Women’s age, parity, and use of oral contraceptives were inversely associated with dysmenorrhea, and high stress increased the risk of dysmenorrhea. The effect sizes were generally modest to moderate, with odds ratios varying between 1 and 4. Family history of dysmenorrhea strongly increased its risk, with odds ratios between 3.8 and 20.7. Inconclusive evidence was found for modifiable factors such as cigarette smoking, diet, obesity, depression, and abuse. Dysmenorrhea is a significant symptom for a large proportion of women of reproductive age; however, severe pain limiting daily activities is less common. This review confirms that dysmenorrhea improves with increased age, parity, and use of oral contraceptives and is positively associated with stress and family history of dysmenorrhea. dysmenorrhea; incidence; menstrual pain; natural history; painful menstruation; prevalence; risk factors
Abbreviations: CI, confidence interval; OCP, oral contraceptive pill.
of life, work productivity, and health-care utilization (5–9). As a result, dysmenorrhea is responsible for considerable economic losses due to the costs of medications, medical care, and decreased productivity (1). The prevalence of dysmenorrhea reported in the literature varies substantially. A greater prevalence was generally observed in young women, with estimates ranging from 67% to 90% for those aged 17–24 years (10, 11). A recent large Australian study of senior high school girls found that a higher proportion, 93%, of teenagers reported menstrual pain (12). The studies in adult women are less consistent in reporting prevalence of dysmenorrhea and often focus on a specific group, with rates varying from 15% to 75% (10). Severe pain sufficient to limit daily activities is considerably less common, affecting approximately 7%–15% of women (10), although a study of adolescents and young adults aged 26 years or less reported that 41% of the participants had limitations in their daily activities due to dysmenorrhea (7). A range of risk factors for dysmenorrhea have been identified in the literature, although mixed results have been observed for many of these factors. In general, increased severity of
INTRODUCTION
Dysmenorrhea or painful menstruation is defined as a severe, painful, cramping sensation in the lower abdomen that is often accompanied by other symptoms, such as sweating, headaches, nausea, vomiting, diarrhea, and tremulousness, all occurring just before or during the menses (1). There are 2 types of dysmenorrhea: Primary dysmenorrhea refers to pain with no obvious pathological pelvic disease and almost always first occurs in women 20 years or younger after their ovulatory cycles become established (1). Secondary dysmenorrhea is caused by underlying pelvic conditions or pathology and is more common in women older than 20 years (1, 2). Dysmenorrhea is considered the most common symptom of all menstrual complaints and poses a greater burden of disease than any other gynecological complaint in developing countries (3). Among women of reproductive age worldwide, dysmenorrhea is more prevalent than the other 2 common types of chronic pelvic pain, namely, dyspareunia and noncyclical chronic pelvic pain (4). Being a debilitating condition for many women, it has a major impact on health-related quality 104
Epidemiol Rev 2014;36:104–113
Downloaded from http://epirev.oxfordjournals.org/ at Memorial University of Newfoundland on August 2, 2014
Accepted for publication September 4, 2013.
Epidemiology of Dysmenorrhea 105
MATERIALS AND METHODS
This review is part of a wider literature review on the epidemiology, impact, and health services use related to dysmenorrhea and premenstrual syndrome/premenstrual dysphoric disorder, focusing on the prevalence and/or incidence and risk factors of dysmenorrhea. Published studies in English providing relevant information on dysmenorrhea were identified by searching PubMed and Embase, restricting the population to adult women (aged 18 years or more) and the year of publishing from 2002 to August 2012. The PubMed search field terms used related to this review were “dysmenorrhea” [MeSH] OR “dysmenorrhea”[tiab] OR (“painful”[tiab] AND “menstruation”[tiab]) OR “painful menstruation”[tiab] OR (“menstrual”[tiab] AND “pain”[tiab]) OR “menstrual pain” [tiab], where Medical Subject Headings (MeSH) and Title/ Abstract (tiab) represented the tags. In order to better infer the temporal relationship and to avoid selection bias, only studies adopting longitudinal study design, case-control studies, or cross-sectional studies with large community-based samples were included in this review. Data from included studies were extracted into a standard form including the key characteristics of the studies, main findings, limitations, and conclusions. The definition of dysmenorrhea varied from abdominal or low back pain or cramps of any severity during menstrual bleeding in the previous month to the past 12 months gathered through self-reporting, interview, or daily diary recording. The majority of studies did not limit the severity of pain or distinguish between the types of dysmenorrhea, such as primary or secondary dysmenorrhea. The severity and the type of dysmenorrhea were noted if the study clearly stated these. The reference lists of the studies included in this review were scanned to check for any additional studies not captured by the electronic database search. Quality assessment was performed for the primary studies by using a checklist for appraising medical literature for Epidemiol Rev 2014;36:104–113
cohort/case-control/cross-sectional studies; it is attached as Web Appendix 1 (available at http://aje.oxfordjournals.org/) (24). The checklist addresses potential biases introduced by study design, sample representativeness, comparability of groups (if applicable), quality of measurements, completeness of data, and confounding. A study was rated as good quality if no problem or only minor problems were identified and as poor quality if 4 or more major problems were identified, for the above-mentioned domains. An overall judgment on the quality was made on the basis of the appraisal of each domain, taking into account its expected effect on the results. Review articles providing relevant information on dysmenorrhea were included as supplementary information as they do not apply the same inclusion criteria. In summary, this review used a comprehensive approach to identify and select relevant literature to provide a qualitative synthesis of the most up-to-date, better-designed, and relevant literature on the rate and risk factors for dysmenorrhea. RESULTS
A total of 2,276 articles were retrieved through the search. After applying the selection criteria described above and scanning the reference lists of included studies, we included 15 primary studies: 3 longitudinal studies and 12 populationbased, cross-sectional studies. Three systematic reviews were included as supplementary information, 2 providing information on prevalence and 1 providing information on risk factors of dysmenorrhea. Data from countries not included in the previous systematic review, particularly developing countries, were identified and thus enhance our overall knowledge base on dysmenorrhea that has been based mainly on literature from developed countries. Most studies were rated as moderate-quality only (quality rating included in Table 1), mainly related to potential biases introduced by the design or conduct of the study. The main concerns with most studies were as follows: 1) study design, as cross-sectional studies were often used to identify risk factors; 2) questionable validity of measurement, as retrospective self-reporting of symptom was used by most studies; 3) representativeness of the sample, as insufficient information on the characteristics of nonresponders or drop-outs was provided; 4) no justification of power of the study provided, given the sample size; and/or 5) no quality control method reported for the data collection. In addition, 6 studies omitted key exposure variables such as parity or oral contraceptive pill (OCP) use from the analysis, which may cause potential biases due to possible confounding. Because of the substantial heterogeneity among the studies, in terms of the study population, definition of dysmenorrhea, symptom reporting methods, length of recall or investigation, and various measurements used for the risk factors studied, a meta-analysis was not performed. Instead, a narrative review and qualitative summation on the associations of the risk factors and dysmenorrhea were undertaken. Prevalence and/or incidence
A total of 14 individual studies (3, 25–37) and 2 systematic reviews (4, 38) reported on the prevalence and/or incidence rates of dysmenorrhea.
Downloaded from http://epirev.oxfordjournals.org/ at Memorial University of Newfoundland on August 2, 2014
dysmenorrhea has been suggested to relate to age (13–15), smoking (14, 16, 17), higher body mass index (18), earlier age at menarche (15, 18), nulliparity (15, 19), longer and heavier menstrual flow (15, 18), and family history of dysmenorrhea (20). Women using oral contraceptives generally report less severe dysmenorrhea (14, 15, 21). Depression and stress have also been shown to increase the risk of dysmenorrhea (9, 22). Other common factors, such as education (23), marital status (14), employment (19), alcohol consumption (17, 18), and physical activity (15, 18), show largely negative or inconclusive results. Currently there is a large body of literature on dysmenorrhea, the majority of which provides only a snapshot view of the disorder from cross-sectional studies and suffers from selection bias as they are based on convenience samples of mainly young college students. To our knowledge, there is no current review that has taken these design factors into account. Therefore, this review aims to ascertain more accurate estimates of the prevalence and incidence of dysmenorrhea in the community and to determine its risk factors by examining evidence from recent longitudinal and population-based studies. The additional aim of this review is to identify gaps in the literature to inform further research focus.
106 Ju et al.
Table 1. Characteristics of Primary Studies (Published Between 2002 and 2011) and Reported Rates for Dysmenorrhea First Author, Year (Reference No.)
Study Quality
Country
No. of Participants
Age Group, Years
Reporting Method
Length of Investigation/ Recall
Hormonal Contraception
Type of Dysmenorrhea
Rate (Prevalence/Incidence) of Dysmenorrhea, %
Definition of Dysmenorrhea
Overalla
Mild
Moderate
Severe
Longitudinal Study Ohde, 2008 (30)
Moderate
Japan
823
18–51
Daily diary
1 month
Not specified
Not specified
Any pain
15.8
Wang, 2004 (36)
Moderate-good
China
388
20–34
Daily diary
12 months or until pregnancy
No
Not specified
Any pain
Incidence, 28.0; prevalence, 44.4
Weissman, 2004 (37)
Moderate-good
United States
404
19–46
Self-reporting
Past 12 months
Yes
Primary
Any pain
76.0
Abenhaim, 2006 (25)
Moderate
United States
904
36–44
Self-reporting
Not specified
No
Not specified
Moderate-severe
36.7
Burnett, 2005 (26)
Moderate
Canada
≥18
Interview
Not specified
Yes
Primary
Any pain Limiting activity
60.4 20.6
Harlow, 2002 (39)
Moderate
United States
976
36–44
Interview
Varied (up to 5 years after menarche)
Yes
Not specified
Any pain
Not reported
Laszlo, 2008 (27)
Moderate
Hungary
2,722
Vol. 36, 2014 DOI: 10.1093/epirev/mxt009 Advance Access publication: November 26, 2013
The Prevalence and Risk Factors of Dysmenorrhea
Hong Ju*, Mark Jones, and Gita Mishra * Correspondence to Hong Ju, Centre for Longitudinal and Life Course Research, School of Population Health, University of Queensland, Herston Road, Herston, QLD 4006, Australia (e-mail: [email protected]).
Dysmenorrhea is a common menstrual complaint with a major impact on women’s quality of life, work productivity, and health-care utilization. A comprehensive review was performed on longitudinal or case-control or crosssectional studies with large community-based samples to accurately determine the prevalence and/or incidence and risk factors of dysmenorrhea. Fifteen primary studies, published between 2002 and 2011, met the inclusion criteria. The prevalence of dysmenorrhea varies between 16% and 91% in women of reproductive age, with severe pain in 2%–29% of the women studied. Women’s age, parity, and use of oral contraceptives were inversely associated with dysmenorrhea, and high stress increased the risk of dysmenorrhea. The effect sizes were generally modest to moderate, with odds ratios varying between 1 and 4. Family history of dysmenorrhea strongly increased its risk, with odds ratios between 3.8 and 20.7. Inconclusive evidence was found for modifiable factors such as cigarette smoking, diet, obesity, depression, and abuse. Dysmenorrhea is a significant symptom for a large proportion of women of reproductive age; however, severe pain limiting daily activities is less common. This review confirms that dysmenorrhea improves with increased age, parity, and use of oral contraceptives and is positively associated with stress and family history of dysmenorrhea. dysmenorrhea; incidence; menstrual pain; natural history; painful menstruation; prevalence; risk factors
Abbreviations: CI, confidence interval; OCP, oral contraceptive pill.
of life, work productivity, and health-care utilization (5–9). As a result, dysmenorrhea is responsible for considerable economic losses due to the costs of medications, medical care, and decreased productivity (1). The prevalence of dysmenorrhea reported in the literature varies substantially. A greater prevalence was generally observed in young women, with estimates ranging from 67% to 90% for those aged 17–24 years (10, 11). A recent large Australian study of senior high school girls found that a higher proportion, 93%, of teenagers reported menstrual pain (12). The studies in adult women are less consistent in reporting prevalence of dysmenorrhea and often focus on a specific group, with rates varying from 15% to 75% (10). Severe pain sufficient to limit daily activities is considerably less common, affecting approximately 7%–15% of women (10), although a study of adolescents and young adults aged 26 years or less reported that 41% of the participants had limitations in their daily activities due to dysmenorrhea (7). A range of risk factors for dysmenorrhea have been identified in the literature, although mixed results have been observed for many of these factors. In general, increased severity of
INTRODUCTION
Dysmenorrhea or painful menstruation is defined as a severe, painful, cramping sensation in the lower abdomen that is often accompanied by other symptoms, such as sweating, headaches, nausea, vomiting, diarrhea, and tremulousness, all occurring just before or during the menses (1). There are 2 types of dysmenorrhea: Primary dysmenorrhea refers to pain with no obvious pathological pelvic disease and almost always first occurs in women 20 years or younger after their ovulatory cycles become established (1). Secondary dysmenorrhea is caused by underlying pelvic conditions or pathology and is more common in women older than 20 years (1, 2). Dysmenorrhea is considered the most common symptom of all menstrual complaints and poses a greater burden of disease than any other gynecological complaint in developing countries (3). Among women of reproductive age worldwide, dysmenorrhea is more prevalent than the other 2 common types of chronic pelvic pain, namely, dyspareunia and noncyclical chronic pelvic pain (4). Being a debilitating condition for many women, it has a major impact on health-related quality 104
Epidemiol Rev 2014;36:104–113
Downloaded from http://epirev.oxfordjournals.org/ at Memorial University of Newfoundland on August 2, 2014
Accepted for publication September 4, 2013.
Epidemiology of Dysmenorrhea 105
MATERIALS AND METHODS
This review is part of a wider literature review on the epidemiology, impact, and health services use related to dysmenorrhea and premenstrual syndrome/premenstrual dysphoric disorder, focusing on the prevalence and/or incidence and risk factors of dysmenorrhea. Published studies in English providing relevant information on dysmenorrhea were identified by searching PubMed and Embase, restricting the population to adult women (aged 18 years or more) and the year of publishing from 2002 to August 2012. The PubMed search field terms used related to this review were “dysmenorrhea” [MeSH] OR “dysmenorrhea”[tiab] OR (“painful”[tiab] AND “menstruation”[tiab]) OR “painful menstruation”[tiab] OR (“menstrual”[tiab] AND “pain”[tiab]) OR “menstrual pain” [tiab], where Medical Subject Headings (MeSH) and Title/ Abstract (tiab) represented the tags. In order to better infer the temporal relationship and to avoid selection bias, only studies adopting longitudinal study design, case-control studies, or cross-sectional studies with large community-based samples were included in this review. Data from included studies were extracted into a standard form including the key characteristics of the studies, main findings, limitations, and conclusions. The definition of dysmenorrhea varied from abdominal or low back pain or cramps of any severity during menstrual bleeding in the previous month to the past 12 months gathered through self-reporting, interview, or daily diary recording. The majority of studies did not limit the severity of pain or distinguish between the types of dysmenorrhea, such as primary or secondary dysmenorrhea. The severity and the type of dysmenorrhea were noted if the study clearly stated these. The reference lists of the studies included in this review were scanned to check for any additional studies not captured by the electronic database search. Quality assessment was performed for the primary studies by using a checklist for appraising medical literature for Epidemiol Rev 2014;36:104–113
cohort/case-control/cross-sectional studies; it is attached as Web Appendix 1 (available at http://aje.oxfordjournals.org/) (24). The checklist addresses potential biases introduced by study design, sample representativeness, comparability of groups (if applicable), quality of measurements, completeness of data, and confounding. A study was rated as good quality if no problem or only minor problems were identified and as poor quality if 4 or more major problems were identified, for the above-mentioned domains. An overall judgment on the quality was made on the basis of the appraisal of each domain, taking into account its expected effect on the results. Review articles providing relevant information on dysmenorrhea were included as supplementary information as they do not apply the same inclusion criteria. In summary, this review used a comprehensive approach to identify and select relevant literature to provide a qualitative synthesis of the most up-to-date, better-designed, and relevant literature on the rate and risk factors for dysmenorrhea. RESULTS
A total of 2,276 articles were retrieved through the search. After applying the selection criteria described above and scanning the reference lists of included studies, we included 15 primary studies: 3 longitudinal studies and 12 populationbased, cross-sectional studies. Three systematic reviews were included as supplementary information, 2 providing information on prevalence and 1 providing information on risk factors of dysmenorrhea. Data from countries not included in the previous systematic review, particularly developing countries, were identified and thus enhance our overall knowledge base on dysmenorrhea that has been based mainly on literature from developed countries. Most studies were rated as moderate-quality only (quality rating included in Table 1), mainly related to potential biases introduced by the design or conduct of the study. The main concerns with most studies were as follows: 1) study design, as cross-sectional studies were often used to identify risk factors; 2) questionable validity of measurement, as retrospective self-reporting of symptom was used by most studies; 3) representativeness of the sample, as insufficient information on the characteristics of nonresponders or drop-outs was provided; 4) no justification of power of the study provided, given the sample size; and/or 5) no quality control method reported for the data collection. In addition, 6 studies omitted key exposure variables such as parity or oral contraceptive pill (OCP) use from the analysis, which may cause potential biases due to possible confounding. Because of the substantial heterogeneity among the studies, in terms of the study population, definition of dysmenorrhea, symptom reporting methods, length of recall or investigation, and various measurements used for the risk factors studied, a meta-analysis was not performed. Instead, a narrative review and qualitative summation on the associations of the risk factors and dysmenorrhea were undertaken. Prevalence and/or incidence
A total of 14 individual studies (3, 25–37) and 2 systematic reviews (4, 38) reported on the prevalence and/or incidence rates of dysmenorrhea.
Downloaded from http://epirev.oxfordjournals.org/ at Memorial University of Newfoundland on August 2, 2014
dysmenorrhea has been suggested to relate to age (13–15), smoking (14, 16, 17), higher body mass index (18), earlier age at menarche (15, 18), nulliparity (15, 19), longer and heavier menstrual flow (15, 18), and family history of dysmenorrhea (20). Women using oral contraceptives generally report less severe dysmenorrhea (14, 15, 21). Depression and stress have also been shown to increase the risk of dysmenorrhea (9, 22). Other common factors, such as education (23), marital status (14), employment (19), alcohol consumption (17, 18), and physical activity (15, 18), show largely negative or inconclusive results. Currently there is a large body of literature on dysmenorrhea, the majority of which provides only a snapshot view of the disorder from cross-sectional studies and suffers from selection bias as they are based on convenience samples of mainly young college students. To our knowledge, there is no current review that has taken these design factors into account. Therefore, this review aims to ascertain more accurate estimates of the prevalence and incidence of dysmenorrhea in the community and to determine its risk factors by examining evidence from recent longitudinal and population-based studies. The additional aim of this review is to identify gaps in the literature to inform further research focus.
106 Ju et al.
Table 1. Characteristics of Primary Studies (Published Between 2002 and 2011) and Reported Rates for Dysmenorrhea First Author, Year (Reference No.)
Study Quality
Country
No. of Participants
Age Group, Years
Reporting Method
Length of Investigation/ Recall
Hormonal Contraception
Type of Dysmenorrhea
Rate (Prevalence/Incidence) of Dysmenorrhea, %
Definition of Dysmenorrhea
Overalla
Mild
Moderate
Severe
Longitudinal Study Ohde, 2008 (30)
Moderate
Japan
823
18–51
Daily diary
1 month
Not specified
Not specified
Any pain
15.8
Wang, 2004 (36)
Moderate-good
China
388
20–34
Daily diary
12 months or until pregnancy
No
Not specified
Any pain
Incidence, 28.0; prevalence, 44.4
Weissman, 2004 (37)
Moderate-good
United States
404
19–46
Self-reporting
Past 12 months
Yes
Primary
Any pain
76.0
Abenhaim, 2006 (25)
Moderate
United States
904
36–44
Self-reporting
Not specified
No
Not specified
Moderate-severe
36.7
Burnett, 2005 (26)
Moderate
Canada
≥18
Interview
Not specified
Yes
Primary
Any pain Limiting activity
60.4 20.6
Harlow, 2002 (39)
Moderate
United States
976
36–44
Interview
Varied (up to 5 years after menarche)
Yes
Not specified
Any pain
Not reported
Laszlo, 2008 (27)
Moderate
Hungary
2,722
