Verbal autopsy

Verbal autopsy (VA) is a method of gathering information about symptoms and circumstances for a deceased individual to determine his or her cause of death. Health information and a description of events prior to death are acquired from conversations or interviews with a person or persons familiar with the deceased and analyzed by health professionals or computer algorithms to assign likely cause(s) of death. Verbal autopsy (VA) is a method of gathering information about symptoms and circumstances for a deceased individual to determine his or her cause of death. Health information and a description of events prior to death are acquired from conversations or interviews with a person or persons familiar with the deceased and analyzed by health professionals or computer algorithms to assign likely cause(s) of death. Verbal autopsy is used in settings where most deaths are otherwise undocumented, which typically means in low- and middle-income countries. Estimates suggest a majority of the 60 million annual global deaths occur without medical attention or official medical certification of the cause of death. VA attempts to establish causes of death for otherwise undocumented subjects, allowing scientists to analyze disease patterns and direct public health policy decisions. Noteworthy large-scale uses of the verbal autopsy method include the Million Death Study in India, China's national program to document causes of death in rural areas, the Global Burden of Disease Study 2010, and the INDEPTH Network multi-site study. VA is increasingly recognised as an important component of national CRVS (Civil Registration and Vital Statistics) systems. The term verbal autopsy was first coined in a project of the Department of International Health of Johns Hopkins School of Hygiene and Public Health which ran from 1965 to 1973 in Punjab, India. Two research projects were located in villages near Ludhiana, with headquarters in Narangwal village. Objectives of the projects were Seven years later (1980), the Ministry of Health of Egypt conducted an investigation for prevention of child mortality from DD using a variety of intervention methods for a total population of 200,000, including 29000 children below the age of 5 in three different districts. The VA method as originally developed in Narangwal was slightly modified to the Egyptian setting and again used to identify prevailing mortality patterns among preschoolers. Following implementation of different treatment schedules, child mortality rates dropped significantly in specific input villages over the period of study. The project site was re-visited six years following completion of the investigation confirming utility and effectiveness of the VA method, and applied intervention modalities respectively. Many iterations and variations of the questionnaires used in VA have been developed by health professionals and researchers. The World Health Organization (WHO), exercising its global mandate to set norms and standards for health, published a book outlining VA standards in 2007. At that time, the emphasis was primarily on standard paper questionnaires that could subsequently be evaluated by physicians to assign causes of death. However, work was already underway in parallel to develop methods for automatically processing VA interview material, because the time, cost and consistency with which physicians were able to assign causes of death to VA interview material were major constraints on the overall process, particularly for large-scale approaches. Additionally, the reason that many deaths were not certified routinely in resource-challenged settings was often associated with a lack of available physicians. Tentative versions of automatic methods were tested in Vietnam in 2003 and in Ethiopia in 2006. Methodological development was led by Prof. Peter Byass at the Umeå Centre for Global Health Research in Sweden, and the name InterVA (for Interpreting Verbal Autopsy) was coined. As it became increasingly clear that automated interpretation of VA was a promising approach, WHO gave further attention to the structure of the VA interview from the perspective that the interview material might be automatically processed. In 2012 WHO published the first VA standard that was specifically designed for automated processing, defining both interview questions and cause of death categories linked to ICD-10. This was followed by the release of the InterVA-4 model which directly corresponded to the 2012 WHO standard. The open-access InterVA-4 knowledge base was also incorporated into the related InsilicoVA model, which set out to analyse standard VA data using a more complex statistical method. Around the same time, the Population Health Metrics Research Consortium (PHMRC) were undertaking an empirical study based at several tertiary hospitals to collect a reference database linking clinically investigated final illnesses to subsequent VA interviews. This was envisaged as a knowledge base for building automated VA models, and several possible strategies were proposed at a conference in Indonesia in 2011. The reference database was subsequently made publicly available. However, it was not fully compliant with the 2012 WHO VA standard for VA interviews or cause of death categories. An automated model called SmartVA-Analyze, based on the content of the PHMRC reference database and using the Tariff model, was subsequently released.