IHME develops fast, affordable ways for countries to better identify causes of death in populations

New research by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington shows that innovative and improved methods for analyzing verbal autopsies – a method of determining individuals' causes of death in countries without a complete vital registration system – are fast, effective, and inexpensive, and could be invaluable for countries struggling to understand disease trends.

While many high-income countries such as the United States, Canada, and Australia have death certification systems, many countries cannot afford these systems, which means causes of death are not officially recorded. As a result, these countries lack critical information about why people are dying and which risk factors contribute to those deaths, as they attempt to track and address health challenges.

Verbal autopsy (VA) consists of a trained interviewer using a questionnaire to collect information about the signs, symptoms, and demographic characteristics of a recently deceased person from an individual who knew them. Methods used to analyze interviews and assign a cause of death include physician certification, whereby physicians review each questionnaire to assign a cause, and new automated methods where the VA interview is conducted on a hand-held device and a cause of death is automatically generated at the end of the interview. Until now, there has been no clear evidence as to how accurate the methods were, and some methods such as the physician review were costly and time consuming.

A new collection of research published in the Population Health Metrics thematic series, Verbal autopsy: innovations, applications, opportunities, provides the most up-to-date research in the field, including the use of a new automated tool to do the analysis instantaneously at the completion of the interview. Yielding fast and affordable results, this new automated method outperforms any other method to date.

"Accountability is becoming increasingly important to both governments and funders as they try to allocate resources and measure success," said Dr. Christopher Murray, Director of IHME and Professor of Global Health at the University of Washington. "With the new innovative methods outlined in our research, countries can now choose the best and most cost-effective verbal autopsy techniques to better monitor progress toward health and development goals."

The Random Forest method, developed by IHME, performed better than physician review, which traditionally has been seen as the gold standard, and is also cheaper and provides faster results.

The Random Forest method was more accurate than physicians in assigning the correct cause of death to individual VAs for adults and children older than 28 days. For VAs on adults, the Random Forest method performed 27% better than physicians when there is no accompanying medical information from those interviewed. In cases where there is additional information, the Random Forest method was better by 8%. For VAs on children older than 28 days, the Random Forest method performed 28% better than physicians with no additional medical information and 8% better for VAs including other information.