Documenting Mortality in Crises: What Keeps Us from Doing Better

This is the second in a series of articles on conducting research during complex humanitarian emergencies. The first is at PLoS Med 5(4): e89. doi:10.1371/journal. pmed.0050089 T he effects of crises (man-made or natural disasters) on physical health are ultimately quantifiable as a rise in mortality. Precise and unbiased estimates of mortality rates (deaths per person-time) or excess death tolls (deaths attributable to the presence of the crisis) are critical to grading the severity of a crisis at its onset and over time, and adjusting relief operations accordingly [1,2]. Indeed, the onset of emergencies is commonly defined as a doubling of mortality rate from the pre-crisis baseline, or the crossing of fixed thresholds, typically one death per 10,000 person-days [2]. In reality, because mortality increases only after a crisis has evolved, acute malnutrition may be a better indicator for early crisis detection [3], and data on morbidity and on the coverage of interventions against the main known risk factors for poor health outcomes (e.g., insufficient water and sanitation, lack of preventive and curative health services, etc.) are more useful to target relief programmes and minimise preventable deaths. Mortality data also provide a basis for advocacy, which may be " humanitarian " (calling for appropriate assistance) or " political " (for example, calling for compliance with international humanitarian law [IHL], a set of rules that seek to limit the effects of armed conflict for humanitarian reasons [see http://www.icrc.org/web/eng/ siteeng0.nsf/html/humanitarian-law-factsheet]). As historical documents, mortality data also illuminate the consequences of humanity's failures to resolve conflicts non-violently and to protect vulnerable groups from war or disasters. In Table 1, we outline these two main functions of mortality data—the support of relief operations and evidence-building for advocacy/ documentation. However, we believe that both functions can often be served simultaneously. In this article, we attempt to summarise how mortality within crisis-affected populations is documented at present, discuss our perceptions of the barriers to better mortality measurement, and suggest ways by which these barriers might be overcome (see Box 1 for the main suggested actions). Prospective surveillance. The gold standard tools for monitoring mortality are vital registration systems complemented by frequent census exercises. However, these tools were missing or deficient in all recent high-mortality crises (such as in Darfur, the Democratic Republic of the Congo [DRC], and Angola), with the exception of Bosnia, where vital registration systems continued to function throughout the war [4]. Hence, guidelines …