Adult mortality patterns in Yemen before and during armed conflict and the COVID-19 pandemic: Evidence from a web survey of the global diaspora

Abstract

Background The ongoing war in Yemen has created a severe and protracted crisis that has left nearly three-quarters of the population in need of urgent humanitarian assistance. Despite eight years of conflict there exist few robust estimates of how the crisis and COVID-19 pandemic have affected mortality in Yemen. The security situation has limited access to affected populations and thus required novel alternatives to local mortality surveys. Methods We used a web-based, respondent-driven sampling method to disseminate a mortality survey amongst the global Yemeni diaspora. We used mortality estimation methods and survival analysis to calculate mortality and/or survivorship amongst respondents’ close family members in Yemen including adults aged 50+, siblings, and children under five years. Results Eighty-nine eligible respondents completed the survey. Respondents provided data on the status of 1704 individuals of whom 85 (5%) had died; of these 65 (3.8%) were reported to have died in Yemen. An analysis of survivorship of respondents’ parents after their 50th birthday (adjusted for birth cohort and gender) provided weak evidence that the war and pandemic periods were associated with higher mortality when compared to the pre-war period. Analysis of the subset of individuals who died in Yemen also suggested an increased hazard of dying during the war/pandemic period; however, these results were non-significant. Sibling mortality amongst those aged 15–49 was 0.7 per 1000 person-years during the pre-war period compared to 1.1 during the war/pandemic period amongst males, and 0.8 versus 0.0 amongst females; however, these estimates reflected small numbers of deaths. The number of deaths amongst children under five in Yemen was too low to allow meaningful analysis; only three of the seven deaths in this group occurred during the analysis period. Conclusions Our data suggest increased mortality during the war/pandemic period, compared to the pre-war period, among elderly Yemenis. Our findings require careful interpretation as our small and non-representative sample appeared skewed towards higher-income, urban communities. Surveys of diaspora populations offer a promising means of describing mortality patterns in crisis-affected populations; however, large numbers of respondents are likely required to achieve accurate mortality estimates and attempt adjustment for selection bias.