The burden of headache disorders in the adult general population of the Kingdom of Saudi Arabia: estimates from a cross-sectional population-based study including a health-care needs assessment.

BACKGROUND: We have previously shown headache to be highly prevalent among adults in Saudi Arabia. Here we estimate associated symptom burden and impaired participation (impaired use of time, lost productivity and disengagement from social activity), and use these estimates to assess headache-related health-care needs in Saudi Arabia. METHODS: A randomised cross-sectional survey included 2,316 adults (18-65 years) from all 13 regions of the country. It used the standardised methodology of the Global Campaign against Headache with a culturally mandated modification: engagement by cellphone using random digit-dialling rather than door-to-door visits. Enquiry used the HARDSHIP questionnaire, with diagnostic questions based on ICHD-3 beta, questions on symptom burden, enquiries into impaired participation using the HALT index and questions about activity yesterday in those reporting headache yesterday (HY). Health-care "need" was defined in terms of likelihood of benefit. We counted all those with headache on ≥ 15 days/month, with migraine on ≥ 3 days/month, or with migraine or TTH and meeting either of two criteria: a) proportion of time in ictal state (pTIS) > 3.3% and intensity ≥ 2 (moderate-severe); b) ≥ 3 lost days from paid work and/or household chores during 3 months. RESULTS: For all headache, mean frequency was 4.3 days/month, mean duration 8.4 h, mean intensity 2.3 (moderate). Mean pTIS was 3.6%. Mean lost days from work were 3.9, from household chores 6.6, from social/leisure activities 2.0. Of participants reporting HY, 37.3% could do less than half their expected activity, 19.8% could do nothing. At population-level (i.e., for every adult), 2.5 workdays (potentially translating into lost GDP), 3.6 household days and 1.3 social/leisure days were lost to headache. According to HY data, mean total impaired participation (not distinguishing between work, household and social/leisure) was 6.8%. A total of 830 individuals (35.8%) fulfilled one or more of our needs assessment criteria. CONCLUSION: A very high symptom burden is associated with a commensurately high burden of impaired participation. The economic cost appears to be enormous. Over a third of the adult population are revealed to require headache-related health care on the basis of being likely to benefit, demanding highly efficient organization of care.

The burden attributable to primary headache disorders in children and adolescents in Ethiopia: estimates from a national schools-based study.

BACKGROUND: We previously reported high prevalences of headache disorders among children (6-11 years) and adolescents (12-17 years) in Ethiopia. Here we provide data on headache-attributed burden collected contemporaneously from the same study participants. Part of the global schools-based programme within the Global Campaign against Headache, the study is the first to present such data from sub-Saharan Africa. METHODS: A cross-sectional survey following the generic protocol for the global study was conducted in six schools (urban and rural), in Addis Ababa city and three regions of Ethiopia. The child or adolescent versions of the Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) structured questionnaires were self-completed under supervision by pupils in class. Headache diagnostic questions were based on ICHD-3 beta but for the inclusion of undifferentiated headache (UdH). RESULTS: Of 2,349 eligible participants, 2,344 completed the questionnaires (1,011 children [43.1%], 1,333 adolescents [56.9%]; 1,157 males [49.4%], 1,187 females [50.6%]; participating proportion 99.8%). Gender- and age-adjusted 1-year prevalence of headache, reported previously, was 72.8% (migraine: 38.6%; tension-type headache [TTH]: 19.9%; UdH: 12.3%; headache on ≥ 15 days/month (H15+): 1.2%). Mean headache frequency was 2.6 days/4 weeks but, with mean duration of 2.7 h, mean proportion of time with headache was only 1.0% (migraine: 1.4%; TTH: 0.7%; H15+: 9.1%). Mean intensity was 1.8 on a scale of 1-3. Symptomatic medication was consumed on about one third of headache days across headache types. Lost school time reportedly averaged 0.7 days over the preceding 4 weeks, representing 3.5% of school time, but was 2.4 days/4 weeks (12.0%) in the important small minority with H15+. However, actual absences with headache the day before indicated averages overall of 9.7% of school time lost, and 13.3% among those with migraine. Emotional impact and quality-of-life scores reflected other measures of burden, with clear adverse impact gradients (H15 + > migraine > TTH > UdH). CONCLUSIONS: The high prevalence of headache among children and adolescents in Ethiopia, who represent half its population, is associated with substantial burden. Lost school time is probably the most important consequence. Estimates suggest a quite deleterious effect, likely to be reflected in both individual prospects and the prosperity of society.

The prevalence of headache in the adult population of Morocco: a cross-sectional population-based study.

BACKGROUND: The series of population-based studies conducted by the Global Campaign against Headache has, so far, included Pakistan and Saudi Arabia from the Eastern Mediterranean Region. The Maghreb countries of North Africa, also part of this Region, are geographically apart and culturally very different from these countries. Here we report a study in Morocco. METHODS: We applied the standardised methodology of Global Campaign studies, with cluster-randomized sampling in regions of Morocco selected to be representative of its diversities. In three of these regions, in accordance with this methodology, we made unannounced visits to randomly selected households and, from each, interviewed one randomly selected adult member (aged 18-65 years) using the HARDSHIP structured questionnaire translated into Moroccan Arabic and French. In a fourth region (Fès), because permission for such sampling was not given by the administrative authority, people were randomly stopped in streets and markets and, when willing, interviewed using the same questionnaire. This was a major protocol violation. RESULTS: We included 3,474 participants, 1,074 (41.7%) from Agadir, 1,079 (41.9%) from Marrakech, 422 (16.4%) from Tétouan and 899 from Fès. In a second protocol violation, interviewers failed to record the non-participating proportion. In the main analysis, excluding Fès, observed 1-year prevalence of any headache was 80.1% among females, 68.2% among males. Observed 1-day prevalence (headache yesterday) was 17.8%. After adjustment for age and gender, migraine prevalence was 30.8% (higher among females [aOR = 1.6]) and TTH prevalence 32.1% (lower among females [aOR = 0.8]). Headache on ≥ 15 days/month (H15+) was very common (10.5%), and in more than half of cases (5.9%) associated with acute medication overuse (on ≥ 15 days/month) and accordingly diagnosed as probable medication-overuse headache (pMOH). Both pMOH (aOR = 2.6) and other H15+ (aOR = 1.9) were more common among females. In the Fès sample, adjusted prevalences were similar, numerically but not significantly higher except for other H15+. CONCLUSIONS: While the 1-year prevalence of headache among adults in Morocco is similar to that of many other countries, migraine on the evidence here is at the upper end of the global range, but not outside it. H15 + and pMOH are very prevalent, contributing to the high one-day prevalence of headache.

The prevalence and demographic associations of headache in the adult population of Peru: a national cross-sectional population-based study.

BACKGROUND: The Global Campaign against Headache is conducting a series of population-based studies to fill the large geographical gaps in knowledge of headache prevalence and attributable burden. One major region not until now included is South America. Here we present a study from Peru, a country of 32.4 million inhabitants located at the west coast of South America, notable for its high Andes mountains. METHODS: The study was conducted in accordance with the standardized methodology used by the Global Campaign. It was a cross-sectional survey using cluster randomised sampling in five regions to derive a nationally representative sample, visiting households unannounced, and interviewing one randomly selected adult member (aged 18-65 years) of each using the Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire translated into South American Spanish. The neutral screening question ("Have you had headache in the last year?") was followed by diagnostic questions based on ICHD-3 and demographic enquiry. RESULTS: The study included 2,149 participants from 2,385 eligible households (participating proportion 90.1%): 1,065 males and 1,084 females, mean age 42.0 ± 13.7 years. The observed 1-year prevalence of all headache was 64.6% [95% CI: 62.5-66.6], with age-, gender- and habitation-adjusted prevalences of 22.8% [21.0-24.6] for migraine (definite + probable), 38.9% [36.8-41.0] for tension-type headache (TTH: also definite + probable), 1.2% [0.8-1.8] for probable medication-overuse headache (pMOH) and 2.7% [2.1-3.5] for other headache on ≥ 15 days/month (H15+). One-day prevalence of headache (reported headache yesterday) was 12.1%. Migraine was almost twice as prevalent among females (28.2%) as males (16.4%; aOR = 2.1; p < 0.001), and strongly associated with living at very high altitude (aOR = 2.5 for > 3,500 versus < 350 m). CONCLUSION: The Global Campaign's first population-based study in South America found headache disorders to be common in Peru, with prevalence estimates for both migraine and TTH substantially exceeding global estimates. H15 + was also common, but with fewer than one third of cases diagnosed as pMOH. The association between migraine and altitude was confirmed, and found to be strengthened at very high altitude. This association demands further study.

The prevalence and demographic associations of headache in the adult population of Benin: a cross-sectional population-based study.

BACKGROUND: The Global Burden of Disease (GBD) study is increasingly well informed with regard to headache disorders, but sub-Saharan Africa (SSA) remains one of the large regions of the world with limited data directly derived from population-based studies. The Global Campaign against Headache has conducted three studies in this region: Ethiopia in the east, Zambia in the south and Cameroon in Central SSA. Here we report a similar study in Benin, the first from West SSA. METHODS: We used the same methods and questionnaire, applying cluster-randomized sampling in three regions of the country, randomly selecting households in each region, visiting these unannounced and randomly selecting one adult member (aged 18-65 years) of each household. The HARDSHIP structured questionnaire, translated into Central African French, was administered face-to-face by trained interviewers. Demographic enquiry was followed by diagnostic questions based on ICHD-3 criteria. RESULTS: From 2,550 households with eligible members, we recruited 2,400 participants (participating proportion 94.1%). Headache ever was reported by almost all (95.2%), this being the lifetime prevalence. Headache in the last year was reported by 74.9%. Age-, gender- and habitation-adjusted estimates of 1-year prevalence were 72.9% for all headache, 21.2% for migraine (including definite and probable), 43.1% for TTH (also including definite and probable), 4.5% for probable medication-overuse (pMOH) and 3.1% for other headache on ≥ 15 days/month. One-day (point) prevalence of headache was 14.8% according to reported headache on the day preceding interview. CONCLUSIONS: Overall, these findings are evidence that headache disorders are very common in Benin, a low-income country. The prevalence of pMOH, well above the estimated global mean of 1-2%, is evidence that poverty is not a bar to medication overuse. The findings are very much the same as those in a similar study in its near neighbour, Cameroon. With regard to migraine, they are reasonably in accord with two of three earlier studies in selected Beninese populations, which did not take account of probable migraine. This study adds to the hitherto limited knowledge of headache in SSA.

Headache in the adult population of Cameroon: prevalence estimates and demographic associations from a cross-sectional nationwide population-based study.

BACKGROUND: Knowledge of headache prevalence, and the burdens attributable to headache disorders, remains incomplete in sub-Saharan Africa (SSA): reliable studies have been conducted only in Zambia (southern SSA) and Ethiopia (eastern SSA). As part of the Global Campaign against Headache, we investigated the prevalence of headache in Cameroon, in Central SSA. METHODS: We used the same methodology as the studies in Zambia and Ethiopia, employing cluster-randomized sampling in four regions of Cameroon, selected to reflect the country's geographic, ethnic and cultural diversities. We visited, unannounced, randomly selected households in each region, and randomly selected one adult member (aged 18-65 years) of each. Trained interviewers administered the Headache-Attributed Restriction, Disability and Impaired Participation (HARDSHIP) structured questionnaire, developed by an international expert consensus group and translated into Central African French. Demographic enquiry was followed by diagnostic questions based on ICHD-3 criteria. RESULTS: Headache was a near-universal experience in Cameroon (lifetime prevalence: 94.8%). Observed 1-year prevalence of headache was 77.1%. Age- and gender-adjusted estimates were 76.4% (95% confidence interval: 74.9-77.9) for any headache, 17.9% (16.6-19.3) for migraine (definite + probable), 44.4% (42.6-46.2) for tension-type headache (TTH; also definite + probable), 6.5% (5.7-7.4) for probable medication-overuse headache (pMOH) and 6.6% (5.8-7.6) for other headache on ≥ 15 days/month (H15 +). One-day prevalence ("headache yesterday") was 15.3%. Gender differentials were as expected (more migraine and pMOH among females, and rather more TTH among males). pMOH increased in prevalence until age 55 years, then declined somewhat. Migraine and TTH were both associated with urban dwelling, pMOH, in contrast, with rural dwelling. CONCLUSIONS: Headache disorders are prevalent in Cameroon. As in Zambia and Ethiopia, estimates for both migraine and TTH exceed global mean estimates. Attributable burden is yet to be reported, but these findings must lead to further research, and measures to develop and implement headache services in Cameroon, with appropriate management and preventative strategies.

The burden of headache disorders in North India: methodology, and validation of a Hindi version of the HARDSHIP questionnaire, for a community-based survey in Delhi and national capital territory region.

BACKGROUND: Knowledge of the prevalence and attributable burden of headache disorders in India is sparse, with only two recent population-based studies from South and East India. These produced conflicting results. A study in North India is needed. We report the methodology of such a study using, and validating, a Hindi translation of the Headache-Attributed Restriction, Disability, Social Handicap, and Impaired Participation (HARDSHIP) questionnaire developed by Lifting The Burden (LTB). Almost half of the Indian population speak Hindi or one of its dialects. METHODS: The study adopted LTB's standardized protocol for population-based studies in a cross-sectional survey using multistage random sampling conducted in urban Delhi and a surrounding rural area. Trained interviewers visited households unannounced, randomly selected one adult member from each and applied the Hindi version of HARDSHIP in face-to-face interviews. The most bothersome headache reported by participants was classified algorithmically into headache on ≥ 15 days/month (H15 +), migraine (including definite and probable) or tension-type headache (including definite and probable). These diagnoses were mutually exclusive. All participants diagnosed with H15 + and a 10% subsample of all others were additionally assessed by headache specialists and classified as above. We estimated the sensitivity and specificity of HARDSHIP diagnoses by comparison with the specialists' diagnoses. RESULTS: From 3,040 eligible households, 2,066 participants were interviewed. The participating proportions were 98.3% in rural areas but 52.9% in urban Delhi. In the validation subsample of 291 participants (149 rural, 142 urban), 61 did not report any headache (seven of those assessed by HARDSHIP, eight by headache specialists and 46 by both) [kappa = 0.83; 95% CI: 0.74-0.91]. In the remaining 230 participants who reported headache in the preceding year, sensitivity, specificity and kappa with (95% CI) were 0.73 (0.65-0.79), 0.80 (0.67-0.90) and 0.43 (0.34-0.58) for migraine; 0.71 (0.56-0.83), 0.80 (0.730.85) and 0.43 (0.37-0.62) for TTH and 0.75 (0.47-0.94), 0.93 (0.89-0.96) and 0.46 (0.34-0.58) for H15 + respectively. CONCLUSION: This study validates the Hindi version of HARDSHIP, finding its performance similar to those of other versions. It can be used to conduct population surveys in other Hindi-speaking regions of India.

Premonitory symptoms in migraine: A REFORM Study.

BACKGROUND: Estimates of proportions of people with migraine who report premonitory symptoms vary greatly among previous studies. Our aims were to establish the proportion of patients reporting premonitory symptoms and its dependency on the enquiry method. Additionally, we investigated the impact of premonitory symptoms on disease burden using Headache Impact Test (HIT-6), Migraine Disability Assessment (MIDAS) and World Health Organization Disability Assessment 2.0 (WHODAS 2.0), whilst investigating how various clinical factors influenced the likelihood of reporting premonitory symptoms. METHODS: In a cross-sectional study, premonitory symptoms were assessed among 632 patients with migraine. Unprompted enquiry was used first, followed by a list of 17 items (prompted). Additionally, we obtained clinical characteristics through a semi-structured interview. RESULTS: Prompted enquiry resulted in a greater proportion reporting premonitory symptoms than unprompted (69.9% vs. 43.0%; p < 0.001) and with higher symptom counts (medians 2, interquartile range = 0-6 vs. 1, interquartile range = 0-1; p < 0.001). The number of symptoms correlated weakly with HIT-6 (ρ = 0.14; p < 0.001) and WHODAS scores (ρ = 0.09; p = 0.041). Reporting postdromal symptoms or triggers increased the probability of reporting premonitory symptoms, whereas monthly migraine days decreased it. CONCLUSIONS: The use of a standardized and optimized method for assessing premonitory symptoms is necessary to estimate their prevalence and to understand whether and how they contribute to disease burden.

The World Health Organization Intersectoral Global Action Plan on Epilepsy and Other Neurological Disorders and the headache revolution: from headache burden to a global action plan for headache disorders.

The World Health Organization (WHO) Intersectoral Global Action Plan on Epilepsy and Other Neurological Disorders was developed by WHO to address the worldwide challenges and gaps in provision of care and services for people with epilepsy and other neurological disorders and to ensure a comprehensive, coordinated response across sectors to the burden of neurologic diseases and to promote brain health across life-course. Headache disorders constitute the second most burdensome of all neurological diseases after stroke, but the first if young and midlife adults are taken into account. Despite the availability of a range of treatments, disability associated with headache disorders, and with migraine, remains very high. In addition, there are inequalities between high-income and low and middle income countries in access to medical care. In line with several brain health initiatives following the WHOiGAP resolution, herein we tailor the main pillars of the action plan to headache disorders: (1) raising policy prioritization and strengthen governance; (2) providing effective, timely and responsive diagnosis, treatment and care; (3) implementing strategies for promotion and prevention; (4) fostering research and innovation and strengthen information systems. Specific targets for future policy actions are proposed. The Global Action Plan triggered a revolution in neurology, not only by increasing public awareness of brain disorders and brain health but also by boosting the number of neurologists in training, raising research funding and making neurology a public health priority for policy makers. Reducing the burden of headache disorders will not only improve the quality of life and wellbeing of people with headache but also reduce the burden of neurological disorders increasing global brain health and, thus, global population health.

What proportion of people with migraine report postdromal symptoms? A systematic review and meta-analysis of observational studies.

BACKGROUND: Postdromal symptoms, following headache resolution, are said to constitute a distinct phase of the migraine attack. We question the evidence for this, with regard both to the nature of such symptoms and to how often they are reported to occur. METHODS: We searched the Pubmed and Embase databases for relevant articles from their inception until 25 May 2023. We included observational studies recording the proportions of participants with migraine reporting one or more postdromal symptoms or specific individual symptoms. Two reviewers independently screened studies for relevance (agreeing on those to be included), extracted data and assessed risk of bias. Data were analyzed using random-effects meta-analysis to establish the proportions of those with migraine reporting one or more postdromal symptoms, whether among the general population or patients in clinic-based samples. RESULTS: Large majorities of participants in either case reported postdromal symptoms: 97% in the only population-based study, and a mean of 86% (95% CI: 71-94%) in four clinic-based studies. The most commonly reported specific symptoms were fatigue (52%; 95% CI: 44-60%), concentration difficulties (35%; 95% CI: 14-65%) and mood changes (29%; 95% CI: 9-64%), none of these being clearly described. These estimates could not be considered reliable: they were subject to substantial study heterogeneity, none of the studies applied International Classification of Headache Disorders definitions of postdromal symptoms, and all had high risk of bias. CONCLUSION: Postdromal symptoms in migraine appear to be very commonly reported, but the data are unreliable with regard both to their nature and to how often they occur. Further studies are needed to conclude that they constitute a distinct phase of migraine.

Migraine in older adults.

Migraine is an evolving, and sometimes lifelong disorder. The prevalence of episodic migraine peaks among individuals aged in their late 30s, implying a tendency for the disorder to remit with increasing age thereafter, whereas chronic migraine is more likely to persist into later life. Diagnosis and treatment of migraine in older adults, defined as individuals aged 60 years or older, is rendered more complex by increasing probabilities of atypical clinical features and comorbidities, with patients' comorbidities sometimes limiting their therapeutic options. However, the changing clinical presentation of migraine over an individual's lifespan is not well characterised. The neurobiological basis of remission in older adults remains unclear, although vascular, neuronal, and hormonal changes are likely to be involved. Long-term longitudinal studies of individuals with migraine would be particularly informative, with the potential not only to suggest new research directions, but also to lead to the identification of novel therapeutic agents. Although several novel migraine medications are becoming available, their effectiveness, tolerability, and safety often remain uncertain in older adults, who have commonly been excluded from the evaluation of these agents in randomised controlled trials, or who constitute only a small proportion of study populations. There is a need to recognise these limitations in the available evidence, and the specific, and often unmet, clinical needs of older adults with migraine, not least because older adults constitute an increasing proportion of populations worldwide.

The HARDSHIP databases: a forthcoming free good from the Global Campaign against Headache.

In order to pursue its purpose of reducing the global burden of headache, the Global Campaign against Headache has gathered data on headache-attributed burden from countries worldwide. These data, from the individual participants in adult population-based studies and child and adolescent schools-based studies, are being collated in two databases, which will be powerful resources for research and teaching and rich information sources for health policy.Here we briefly describe the structure and content of these databases, and announce the intention to make them available in due course as a free good.

Medication overuse headache.

Medication overuse headache (MOH) is a secondary headache disorder attributed to overuse of acute headache medications by a person with an underlying headache disorder, usually migraine or tension-type headache. MOH is common among individuals with 15 or more headache days per month. Although MOH is associated with substantial disability and reductions in quality of life, this condition is often under-recognized. As MOH is both preventable and treatable, it warrants greater attention and awareness. The diagnosis of MOH is based on the history and an unremarkable neurological examination, and is made according to the diagnostic criteria of the International Classification of Headache Disorders third edition (ICHD-3). Pathophysiological mechanisms of MOH include altered descending pain modulation, central sensitization and biobehavioural factors. Treatment of MOH includes the use of headache preventive therapies, but essential to success is eliminating the cause, by reducing the frequency of use of acute headache medication, and perhaps withdrawing the overused medication altogether. Appropriate treatment is usually highly effective, leading to reduced headache burden and acute medication consumption.

Characterizing healthcare utilization patterns in a Danish population with headache: results from the nationwide headache in Denmark (HINDER) panel.

INTRODUCTION: Worldwide, far from all of those who would benefit make use of headache services, largely because of clinical, social, and political barriers to access. Identifying the factors contributing to low healthcare utilization can generate evidence to guide health policy. Our purpose here is better to characterize healthcare utilization patterns in Denmark. METHODS: The Headache in Denmark (HINDER) study is a nationwide cross-sectional survey of people with headache, conducted using SurveyXact (Rambøll Group A/S, Copenhagen). Healthcare utilization was assessed in a study sample generated by population screening and recruitment. Data collection occurred over two weeks, from September 23rd until October 4th, 2021. The questions enquired into disease characteristics, management, burden, medication intake and healthcare utilization. RESULTS: The number of participants included in the HINDER panel was 4,431, with 2,990 (67.5%: 2,522 [84.3%] female, 468 [15.7%] male; mean age 40.9 ± 11.6 years) completing the survey. One quarter of participants (27.7%) disagreed or strongly disagreed that they were able to manage their headache attacks. Most participants (81.7%) agreed or strongly agreed that their headache was a burden in their everyday lives. The most reported acute medications, by 87.2% of participants, were simple analgesics; of note, 8.6% reported using opioids for their headache. One quarter of participants (24.4%) had never consulted a medical doctor for their headache; one in six (16.5%: more than two thirds of the 24.4%) had never done so despite agreeing or strongly agreeing that their headache was a burden in their everyday lives. Two thirds (65.3%) of participants overall, and almost three quarters (72.4%) of those with weekly headache, had tried one or more complementary or alternative therapies outside conventional medical care. CONCLUSIONS: Our findings are indicative of inadequate delivery of headache care in a country that provides free and universal coverage for all its residents. The implications are twofold. First, it is not sufficient merely to make services available: public education and increased awareness are necessary to encourage uptake by those who would benefit. Second, educational interventions in both pre- and postgraduate settings are necessary, but a prerequisite for these is a resetting of policy priorities, properly to reflect the very high population ill-health burden of headache.

The relationship between headache-attributed disability and lost productivity: 3 Attack frequency is the dominating variable.

BACKGROUND: In an earlier paper, we examined the relationship between headache-attributed disability, measured as proportion of time in ictal state, and lost productivity. In a linear model, we found positive and significant associations with lost paid worktime, lost household worktime and total lost productivity (paid + household), but with high variance, which was increased when headache intensity was introduced as a factor. We speculated that analyses based on headache frequency alone as the independent variable, eliminating both the subjectivity of intensity estimates and the uncertainties of duration, might show stronger associations. METHODS: Focusing on migraine, we used individual participant data from 16 countries surveyed either in population-based studies or in the Eurolight project. These data included frequency (headache days/month), usual attack duration (hours), usual headache intensity ("not bad", "quite bad", "very bad") and lost productivity from paid and household work according to enquiries using the Headache-Attributed Lost Time (HALT) questionnaire. We used multiple linear regressions, calculating regression equations along with unstandardized and standardized regression coefficients. We made line and bar charts to visualize relationships. RESULTS: Both frequency and intensity were significant predictors of lost productivity in all multiple linear regressions, but duration was a non-significant predictor in several of the regressions. Predicted productivity in paid work decreased among males by 0.75-0.85 days/3 months for each increase of 1 headache day/month, and among females by 0.34-0.53 days/3 months. In household chores, decreases in productivity for each added day/month of headache were more similar (0.67-0.87 days/3 months among males, 0.83-0.89 days/3 months among females). Visualizations showed that the impact of duration varied little across the range of 2-24 h. The standardized regression coefficients demonstrated that frequency was a much better predictor of lost productivity than intensity or duration. CONCLUSION: In the relationship between migraine-attributed impairment (symptom burden) and lost productivity, frequency (migraine days/month) is the dominating variable - more important than headache intensity and far more important than episode duration. This has major implications for current practice in headache care and for health policy and health-resource investment. Preventative drugs, grossly underutilized in current practice, offer a high prospect of economic benefit (cost-saving), but new preventative drugs are needed with better efficacy and/or tolerability.

Global epidemiology of migraine and its implications for public health and health policy.

Migraine is one of more than 200 headache disorders but stands out among these as a major cause of population ill health. In migraine epidemiology, the key variable is prevalence, but, from the perspective of public health, prevalence is uninformative without burden estimates. Here, we discuss how migraine epidemiology, from a quite recent start, has evolved into the respectable though imperfect science of today, but with the legacy that much of the large corpus of older literature is of questionable reliability. Newer studies have benefited from a universally accepted definition of migraine, while methodological developments have broadened the scope of migraine caseness, and published guidelines address important methodological issues. In the light of these developments, we question the apparent increase in migraine prevalence over time, offering explanations as to why this may be illusory. We suggest that the current best estimates are that global migraine prevalence is 14-15%, and that migraine accounts for 4.9% of global population ill health quantified in years lived with disability (YLDs). These evaluations are probably under-quantified rather than over-quantified, and YLDs are not a comprehensive measure of migraine-attributed burden. Despite these uncertainties, such high estimates of population ill health have clear implications for health policy.

Premonitory symptoms in migraine: a systematic review and meta-analysis of observational studies reporting prevalence or relative frequency.

BACKGROUND: Observational studies on the prevalence of premonitory symptoms in people with migraine, preceding the headache pain (or aura) phase, have shown conflicting results. We conducted a systematic review and meta-analysis to estimate the prevalence, and relative frequency among clinic populations, of premonitory symptoms in people with migraine, overall and of the multifarious individual symptoms, and to review the methodologies used to assess them. METHODS: We searched PubMed and Embase for studies published from database inception until 31st of May 2022. Two investigators independently screened titles, abstracts, and full texts. We retrieved observational studies that reported the prevalence/relative frequency of one or more premonitory symptoms in people with migraine. Two investigators independently extracted data and assessed risk of bias. Results were pooled using random-effects meta-analysis. Our main outcomes were the percentage of people with migraine who experienced at least one premonitory symptom and the percentages who experienced different individual premonitory symptoms. To describe our outcomes, we used the terms prevalence for data from population-based samples and relative frequency for data from clinic-based samples. We also descriptively and critically assessed the methodologies used to assess these symptoms. RESULTS: The pooled estimated prevalence in population-based studies of at least one premonitory symptom was 29% (95% CI: 8-63; I2 99%) and the corresponding pooled estimated relative frequency in clinic-based studies was 66% (95% CI: 45-82; I2 99%). The data from clinic-based studies only supported meta-analysis of 11 of 96 individual symptoms, with relative frequency estimates ranging from 11 to 49%. Risk of bias was determined as high in 20 studies, moderate in seven, and low in two. CONCLUSIONS: The substantial between-study heterogeneity demands cautious interpretation of our estimates. Studies showed wide methodological variations, and many lacked rigor. Overall, the evidence was insufficient to support reliable prevalence estimation or characterization of premonitory symptoms. More data are needed, of better quality, to confirm the existence of a distinctive premonitory phase of migraine, and its features. Methodological guidelines based on expert consensus are a prerequisite.

Barriers to headache care in low- and middle-income countries.

Headache disorders are a common cause of disability globally and lead not only to physical disability but also to financial strain, higher rates of mental health disorders such as depression and anxiety, and reduced economic productivity which negatively impacts gross domestic product (GDP) on a national scale. While data about headache are relatively scarce in low- and middle-income countries (LMICs), those available suggest that headache disorders occur on a similar scale in LMICs as they do in high-income countries. In this manuscript, we discuss common clinical, political, economic and social barriers to headache care for people living in LMICs. These barriers, affecting every aspect of headache care, begin with community perceptions and cultural beliefs about headache, include ineffective headache care delivery systems and poor headache care training for healthcare workers, and extend through fewer available diagnostic and management tools to limited therapeutic options for headache. Finally, we review potential solutions to these barriers, including educational interventions for healthcare workers, the introduction of a tiered system for headache care provision, creation of locally contextualized diagnostic and management algorithms, and implementation of a stepped approach to headache treatment.

The prevalence of primary headache disorders in children and adolescents in Zambia: a schools-based study.

BACKGROUND: The Global Campaign against Headache collects data from children (6-11 years) and adolescents (12-17) to inform health and education policies and contribute to the Global Burden of Disease (GBD) study. This survey in Zambia, part of this global enquiry, was the second from sub-Saharan Africa (SSA). METHODS: Following the generic protocol, this was a schools-based cross-sectional survey. We used the child and adolescent versions of the structured Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire, self-completed by pupils within classes, in a total of nine schools in Lusaka (urban) and Copperbelt (semi-rural). These two of Zambia's ten provinces were selected to represent the country's urban/rural divide. Headache diagnostic questions were based on ICHD-3 except for undifferentiated headache (UdH). RESULTS: Of 2,759 potential participants, 2,089 (615 children [29.4%], 1,474 adolescents [70.6%]) completed questionnaires (participating proportion 75.7%). Children were therefore under-represented (mean age 13.1 ± 2.8 years), while gender distribution (1,128 [54.0%] male, 961 [46.0%] female) was close to expectation. Observed lifetime prevalence of headache was 97.5%. Gender- and age-adjusted 1-year prevalence estimates were 85.8% for all headache, 53.2% for migraine (definite 17.5%, probable 35.7%), 12.1% for tension-type headache (TTH), 14.8% for UdH, 3.3% for all headache on ≥ 15 days/month and 0.9% for probable medication-overuse headache. Headache durations were short: only 28.6% of participants with any headache, and only 10.5% of those diagnosed as probable migraine, reported usual durations of > 2 h (the threshold for definite migraine). Of the latter, 36.6% reported < 1 h, the duration criterion for UdH. There were weak associations of migraine (definite + probable) with female gender, and of TTH and headache on ≥ 15 days/month with adolescence. Headache yesterday was reported by 22.2% of the sample, 25.5% of those with headache. CONCLUSIONS: Headache disorders among young people are prevalent in Zambia. Among them, migraine is the most common, with UdH also highly prevalent. In this study there were diagnostic uncertainties, which rested to a large extent on the distinction between migraine and UdH among the many participants reporting headache of < 2 h' duration. Similar uncertainties occurred in the first study in SSA, in Ethiopia. Because of these, we conclude only that migraine affects at least 17.5% of these age groups in Zambia, which is still a large proportion, adult prevalence in an earlier study being 22.9%. Supplementary estimates of attributed burden are needed to inform public-health and educational policies in Zambia.