The prevalence of primary headache disorders in Nepal: a nationwide population-based study

Abstract

BackgroundHeadache disorders are among the most prevalent and burdensome global public-health problems. Within countries, health policy depends upon knowledge of health within the local populations, but the South-East Asia Region (SEAR), among WHO’s six world regions, is the only one for which no national headache prevalence data are available.MethodsIn a cross-sectional population-based study, adults representative of the Nepali-speaking population aged 18–65 years and living in Nepal were randomly recruited using stratified multistage cluster sampling. They were visited unannounced at home by trained interviewers who used a culturally-adapted Nepali translation of the structured Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire.ResultsThere were 2,100 participants (1,239 females [59.0 %], 861 males [41.0 %]; mean age 36.4 ± 12.8 years) with 9 refusals (participation rate 99.6 %). Over half (1,100; 52.4 %) were resident above 1,000 m and almost one quarter (470; 22.4 %) lived at or above 2,000 m. The 1-year prevalence of any headache was 85.4 ± 1.5 % (gender- and age-adjusted 84.9 %), of migraine 34.7 ± 2.0 % (34.1 %), of tension-type headache (TTH) 41.1 ± 2.1 % (41.5 %), of headache on ≥15 days/month 7.7 ± 1.1 % (7.4 %) and of probable medication-overuse headache (pMOH) 2.2 ± 0.63 % (2.1 %).There was a strong association between migraine and living at altitude ≥1,000 m (AOR = 1.6 [95 % CI: 1.3-2.0]; p < 0.001). There was a less strong association between TTH and urban dwelling (AOR = 1.3 [95 % CI: 1.1-1.6]; p = 0.003), and a possibly artefactual negative association between TTH and living above 1,000 m (AOR = 0.7 [95 % CI: 0.6-0.8]; p < 0.001).ConclusionHeadache disorders are very common in Nepal. Migraine is unusually so, and strongly associated with living at altitude, which in very large part accounts for the high national prevalence: the age- and gender- standardised prevalence in the low-lying Terai is 27.9 %. Headache occurring on ≥15 days/month is also common. This new evidence will inform national health policy and provide a basis for health-care needs assessment. However, research is needed to explain the association between migraine and altitude, since it may be relevant to health-care interventions.

Migraine associated with altitude: results from a population‐based study in Nepal

“…There was slight under-representation of males aged 18-34 years (43.9% rather than 49.8% expected). Other sociodemographic characteristics of the sample reasonably matched those of the national population [4,6,14].…”

“…Age-and gender-standardized migraine prevalence increased with altitude between the lowest category of <500 m and 2499 m (from 27.9% to 45.5%); thereafter, at altitude ≥2500 m, it decreased to 37.9% ( Fig. 1) [6]. Compared with <500 m, adjusted odds ratios for having migraine were significantly greater at all higher altitudes (Table 1), whereas the decline in prevalence from 2000-2499 m to ≥2500 m was also significant (P = 0.025; Table 2).…”

“…We have recently estimated the prevalence of headache in Nepal, recruiting a large sample representative of the adult population of the entire country [6]. The observed 1-year prevalence of migraine was very high, at 34.7% (definite migraine, 17.5%; probable migraine, 17.2%) [6]. Controlling for a wide range of potential confounding factors, we found that this was largely explained by an effect of altitude, i.e.…”

“…living above 1000 m led to a 60% increased likelihood of having migraine. No similar association was observed between high‐altitude living and tension‐type headache (TTH) .…”

Medication-overuse headache: a perspective review

“…Prevalence estimates based on nationally representative data from 16 countries (Brazil, China, Colombia, Georgia, Germany, Iran, Italy, Republic of Korea, Netherlands, Norway, Russian Federation, Spain, Sweden, Turkey, Taiwan and the United States) have been summarized in a systematic review [Westergaard et al 2014b]. Preliminary data from the Republic of Korea reported at a headache congress by Chu and colleagues [Chu et al 2011] have since been published [Park et al 2014], and there are four additional studies from Denmark [Westergaard et al 2014a], India [Kulkarni et al 2015], Nepal [Manandhar et al 2015] and Zambia [Mbewe et al 2015].…”