A global study of pain prevalence across 52 countries: examining the role of country-level contextual factors.

There is wide variation in population-level pain prevalence estimates in studies of survey data around the world. The role of country-level social, economic, and political contextual factors in explaining this variation has not been adequately examined. We estimated the prevalence of unspecified pain in adults aged 25+ years across 52 countries using data from the World Health Survey 2002 to 2004. Combining data sources and estimating multilevel regressions, we compared country-level pain prevalence and explored which country-level contextual factors explain cross-country variations in prevalence, accounting for individual-level demographic factors. The overall weighted age- and sex-standardized prevalence of pain across countries was estimated to be 27.5%, with significant variation across countries (ranging from 9.9% to 50.3%). Women, older persons, and rural residents were significantly more likely to report pain. Five country-level variables had robust and significant associations with pain prevalence: the Gini Index, population density, the Gender Inequality Index, life expectancy, and global region. The model including Gender Inequality Index explained the most cross-country variance. However, even when accounting for country-level variables, some variation in pain prevalence remains, suggesting a complex interaction between personal, local, economic, and political impacts, as well as inherent differences in language, interpretations of health, and other difficult to assess cultural idiosyncrasies. The results give new insight into the high prevalence of pain around the world and its demonstrated association with macrofactors, particularly income and gender inequalities, providing justification for regarding pain as a global health priority.