Verbal autopsy methods to ascertain birth asphyxia deaths in a community-based setting in southern Nepal

The goals of this study were to (1) develop an approach to ascertain birth asphyxia deaths by using verbal autopsy data from a community-based setting in Nepal, and (2) explore variations in birth asphyxia mortality fractions by using different birth asphyxia case definitions and hierarchical classifications.

Data were prospectively collected during a cluster-randomized, community-based trial of health interventions on neonatal mortality in Sarlahi, Nepal from 2002 to 2006. To assign cause of death, 4 computer-assigned, symptom-based asphyxia case definitions; Nepali physician classification; and our independent review of verbal autopsy open narratives were used. Various hierarchical classification approaches to assign cause of death were also explored.

Birth asphyxia specific mortality ranged from 26% to 54%, depending on the computer case definition used. There was poor agreement between computer and physician classification of birth asphyxia. By comparing computer results, physician results, and our independent ascertainment of cause of death, we identified 246 cases of birth asphyxia (32% of neonatal deaths). Allowing for >1 cause of death, 30% and 42% of asphyxia cases also met criteria for prematurity and serious infection, respectively. When a hierarchy was used to assign a single cause of death, the birth asphyxia proportionate mortality was reduced to 12% when identification of deaths because of congenital anomalies, prematurity, and serious infections preceded birth asphyxia.

The use of various verbal autopsy definitions and hierarchical approaches to assign cause of death may substantially affect estimates of birth asphyxia-specific mortality and analyses of risk factors. Verbal autopsy methods need to be standardized and validated to generate accurate global estimates to direct policy and resource allocation in low-middle-income countries.