Introduction
Migraine is a debilitating and common disease affecting millions worldwide [
1]. The Headache Classification Committee of the International Headache Society (IHS) defines
migraine as recurrent episodes of headache often accompanied by nausea, vomiting, photophobia, and phonophobia [
2]. According to the results obtained from global burden disease 2019, migraine is the second cause of disability in the general population and the first disabling factor in women under 50 [
3] in such a way that migraine attacks cause significant changes in the patient’s living conditions, including a decrease in personal, social and occupational performance [
4].
Migraine prevalence varies in different geographical areas. Some studies have shown that the prevalence of migraine in Asian countries is lower than in other countries [
5]. In general, the prevalence of migraine is reported between 2.6% and 21.7%, with an average of 12% [
2]. The National Health Survey (NHIS) results in the United States showed that 15.3% of Americans, including 9.7% of men and 20.7% of women, reported migraines and severe headaches [
6]. The review of epidemiological studies in European countries showed that the prevalence of migraine among adults is between 8 and 17.6%, while it is between 5.2 and 9.1% among children and adolescents[
7]. In Iran, the prevalence of migraine in adults has varied from 5.4–41.6% [
8,
9] and in children and adolescents from 4.8 to 28.1% in various studies [
10,
11]. Based on the previous meta-analysis in Iran in 2016, the prevalence of migraine in Iran was reported as 14% [
12].
Understanding prevalence as a function of age and sex informs how likely migraine might be in a particular patient. Also, discernment of how migraine manifests in different populations can improve the diagnosis of people with unusual presentations. On the other hand, a systematic review and meta-analysis study in 2016 investigated the prevalence of migraine in Iran. Based on this, the present study was conducted to update the results of the mentioned research and estimate the prevalence of migraine in Iran.
Method
This study aimed to estimate the prevalence of migraine based on population-based studies in Iran and the prevalence of migraine in Iranian schoolchildren. Also, subgroup analyses were performed based on diagnostic criteria, gender, and age.
In this systematic review and meta-analysis, the data of the studies were conducted to determine the prevalence of migraine in Iran without a time limit until November 2022. This study was done following the statement of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) [
13]. Therefore, after obtaining the documents, two reviewers (ND, HGH) independently and blind screened based on the title and abstract of the articles. After that, the full text of the articles was evaluated. If there is a difference in the approved articles, the opinion of the third reviewer (KV) was used as a criterion.
Search strategy and inclusion and exclusion criteria
The inclusion criteria included all cross-sectional observational studies that investigated the prevalence of migraine, studies that: the full text of which was available and the information for the study, including the sample size and the criteria for diagnosing migraine; and studies that were published in English and Persian. The exclusion criteria included case report, case series, case-controls, and cohort studies.
After determining the inclusion and exclusion criteria, a systematic search of articles in three Iranian databases, MagIran and SID, with Iranian keywords and four international databases, Science Direct, Scopus, and ISI Web of Science and PubMed, with English keywords Done. The keywords used for searching in this study were selected according to the inclusion criteria based on published primary studies and Medical Subject Headings (MESH Terms) (in the reviewed database) and after a detailed examination of the questions of the study [
14]. The search strategy was added to the supplementary appendix.
Quality evaluation of the studies
The quality of confirmatory (observational) studies was measured in the previous stages using observational studies’ methodological quality measurement tool. The Strobe checklist [
15] was used in this study. This checklist examines various aspects of writing a study, including the title, problem statement, study objectives, study type, statistical population, sampling method, determining the appropriate sample size, defining variables and procedures, study data collection tools, statistical analysis methods, and findings. The assessments in this checklist are done using 32 different items. The studies were given a score in the range of 0–32. Since this systematic reviewincluded studies with good or medium to high quality in the analysis, articles with a score of 16 and above were selected by the authors, and studies with a score of less than 16 were considered poor quality and were omitted.
Data extraction and analysis
Pre-designed forms provided us with information. Various criteria were extracted and entered into the relevant forms, including the number of migraine patients and demographic information (first author, year of publication, country, continent, study population, and average age). We used Comprehensive Meta-Analysis software (Version 2) to analyze the data. The Begg and Mazumdar test was used at a significance level of 0.1. Also, this study used a corresponding Funnel plot and I2 test to check publication bias and heterogeneity, respectively. Also, subgroup analyses were performed based on gender and migraine diagnostic criteria.
Discussion
Based on the results of our study, the prevalence of migraine in the general population of Iran was 15.1% (CI 95%: 10.7–20.9). Subgroup analyses were performed based on gender, diagnostic criteria, and migraine symptoms. Three studies were used to estimate the prevalence of migraine in men and women. According to the results, the prevalence of migraine was reported in women at 26.9% (CI 95%: 21.3–33.3) and in men at 14.9% (CI 95%: 8.9–23.7). This result overlaps with the results of previous studies.
According to a study conducted in Germany, 23% of people over 20 have migraines [
34]. A systematic review and meta-analysis conducted in 2014 examined 21 population-based studies. Based on these results, the statistical results of migraine in the general population of Africa have been reported as 5.61% (95% CI 4.61, 6.70;) which indicates less migraine compared to Iran, also the number of migraines in students has been reported as 14.89% (14.06, 15.74) [
35]. In another systematic review aimed at the epidemiological investigation of migraine in Arab-speaking countries, 23 studies were examined. The prevalence of migraine in the general population was reported in the range between 2.6 and 32%. This study also observed that migraine in school children is in the range of 7.1–13.7% [
36].
Different diagnostic criteria have been introduced to diagnose migraine worldwide. In 1988, the International Headache Society (IHS) introduced the first version of the International Classification of Headache Disorders (ICHD-1) [
37]. Doctors and clinical researchers widely used this new diagnostic classification system. The ICHD-3 was released in early 2018. This version replaced the beta version of ICHD-3 released in 2013 [
37]. Based on the results of our study, the diagnostic criteria of migraine were also examined in this study. Based on this, in 6 studies, migraine diagnosis was made with the help of the second version of the International Headache Criteria (ICHD2), and the prevalence of migraine based on the diagnosis using the ICHD2 tool was reported as 13.7% (CI 95%: 9.6–19.3). With the help of the ICHD3 tool, this value was reported as 17.1% (CI 95%: 7.7–33.6), and with the help of other diagnostic tools, this value was 17.6% (CI 95%: 1.9–69.7).
The prevalence of migraine is related to age and gender [
38]. Out of this number, 77.3% of patients reported a positive family history of migraine. In that study, positive family history was defined as a migraine report in at least one relative, including father, mother, siblings, grandparents, and children [
39].
Although migraine is a common disease in people aged,, its prevalence decreases in this group compared to adults [
40]. According to the results, the prevalence of migraine in Iranian children and adolescents was 11% (CI 95%: 7.5–15.9%). Four studies were used to investigate the prevalence of migraine in children. These studies examined 4571 people aged 5–11 years. Based on the results obtained from these studies, the prevalence of migraine in children was reported as 5.2% (CI 95: 1.3–18.7). Also, a statistical analysis was done by gender, and the results obtained were not statistically significant.
A study stated that the prevalence of migraine in children increases with age [
41]. According to another study, people aged 35 to 44 experienced minor migraines with the least intensity, and people over 45 experienced the most severe headaches [
42]. In another study, it has been stated that the prevalence of migraine reaches its peak between the ages of 35 and 39 years, while the amount of this prevalence is lower at all ends of life (i.e., the relatively low prevalence in children or adolescents and the elderly) [
38].
Although few studies have specifically addressed the prevalence of migraine in children, some population-based studies report a similar increase in migraine in women during puberty [
43]. Based on the results of a Turkish study in school children (6–17 years), the prevalence of migraine was reported to be 26% [
44], while a US study reported this rate to be 6% [
45]. The ratio of migraine prevalence between men and women is not constant in all age ranges. Data from 40,892 men, women, and children in the 2003 US National Health Interview Survey (NHIS) showed that boys and girls have a similar prevalence of migraine until puberty, after which the prevalence increases in both sexes, but the increase of this value is more in women than in men [
43].
Before puberty, girls and boys get migraines at about the same rate. It has been mentioned that migraine occurs earlier in boys [
46]. The peak prevalence of migraine occurs in women of reproductive age, and women experience a more significant burden of migraine symptoms and disability than men. Sex hormones play an important role in migraine epidemiology [
47]. The ratio of prevalence of migraine in women compared to men is approximately 3:1. Although the diagnostic criteria for migraine are the same for men and women, the clinical profile of migraine expression in women is more severe than in men [
48]. Women with migraines experience more prolonged headaches, associated symptoms, migraine-related disabilities, a higher burden of co-morbidities, and worsening with age than men [
43].
A review study examined related articles from China, Japan, and Korea. Based on the results of that study, the prevalence of migraine (based on IHS criteria) among adults was between 6 and 14.3%. Also, the highest complication prevalence was reported between 11 and 20% among women and between 3 and 8% among men [
41]. Global prevalence data from the Global Burden of Disease Study in 2015 show that migraine is two to three times higher in women than in men, but in terms of prevalence, it peaks between 30 and 39 years of age in both sexes [
43].
Limitation
One of the limitations of this study was the small number of studies reviewed. Among the other limitations, we can point out the very high heterogeneity of studies, which made it impossible to perform meta-analysis with many studies. Also, since the studies examined a small number of people, the results of this study cannot be definitively generalized to the general population. Also, this study is not registered in PROSPERO.
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