Verbal autopsy: methods in transition.

Understanding of global health and changing morbidity and mortality is limited by inadequate measurement of population health. With fewer than one-third of deaths worldwide being assigned a cause, this long-standing dearth of information, almost exclusively in the world's poorest countries, hinders understanding of population health and limits opportunities for planning, monitoring, and evaluating interventions. In the absence of routine death registration, verbal autopsy (VA) methods are used to derive probable causes of death. Much effort has been put into refining the approach for specific purposes; however, there has been a lack of harmony regarding such efforts. Subsequently, a variety of methods and principles have been developed, often focusing on a single aspect of VA, and the resulting literature provides an inconsistent picture. By reviewing methodological and conceptual issues in VA, it is evident that VA cannot be reduced to a single one-size-fits-all tool. VA must be contextualized; given the lack of "gold standards," methodological developments should not be considered in terms of absolute validity but rather in terms of consistency, comparability, and adequacy for the intended purpose. There is an urgent need for clarified thinking about the overall objectives of population-level cause-of-death measurement and harmonized efforts in empirical methodological research.