Quantifying excess population mortality in crisis settings is necessary to inform humanitarian responses and conflict resolution efforts. In settings where access to affected populations is heavily constrained by insecurity and bureaucratic restrictions there are few means to obtain the required data to inform population estimates. This project aims to explore novel methods to measure crisis-attributable mortality in Yemen. This project is funded by the UK Foreign, Commonwealth & Development Office.
We have developed the following methods for estimating mortality in Yemen:
- Satellite imagery analysis of cemeteries,
- Key informant capture-recapture, and
- A web-based respondent driven sampling survey of the Yemeni diaspora. As a complement to these methods we also undertook a population denominator reconstruction.
Satellite imagery analysis of cemeteries
The satellite imagery project was led by LSHTM in partnership with the technology and innovation company the Satellite Applications Catapult. Using high-resolution satellite imagery the team quantified burial activity across all identifiable cemeteries within Aden governorate, Yemen to generate estimates on excess deaths. Our findings suggest an increase in burial rates attributable to crisis conditions in a non-representative, disproportionately urban sample of Yemen.
Key informant capture-recapture
The key informant project involved estimating population mortality during the pre-pandemic and pandemic periods in nine purposively selected urban and rural communities of southern and central Yemen (Aden and Ta’iz governorates). We found some evidence of a peak in mortality during the early phase of the pandemic, but death rate estimates were otherwise too imprecise to enable strong inference on trends.
- Adult mortality before and during the first wave of COVID-19 pandemic in nine communities of Yemen: a key informant study
Web-based respondent driven sampling survey of the Yemeni diaspora
The web-based respondent driven sampling (RDS) survey of the Yemeni diaspora project involved using RDS 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 residing within Yemen. Though our findings were underpowered we see some evidence that the war and pandemic periods, or the war period and the pandemic period combined, were associated with a two to threefold increase in hazard of dying compared to the pre-war period. Read more information about this study.
- Adult mortality patterns in Yemen before and during armed conflict and the COVID-19 pandemic: Evidence from a web survey of the global diaspora
Population denominator reconstruction
The population reconstruction project aimed to reconstruct the evolution of Yemen's population between June 2014 and September 2021, at subdistrict level, whilst accounting for growth and internal migration.
Data sets and analysis scripts for this study can be found on GitHub.