A comparative analysis of the InterVA model versus physician review in determining causes of neonatal deaths using verbal autopsy data from Nepal

Abstract

Background: Verbal autopsy is a common method of ascertaining the cause of neonatal death in low resource settings where majority of causes of deaths remain unregistered. We aimed to compare the causes of neonatal deaths assigned by computer algorithm-based model, InterVA (Interpreting Verbal Autopsy) with the usual standard of Physician Review of Verbal Autopsy (PRVA) using the verbal autopsy data collected by Morang Innovative Neonatal Intervention (MINI) study in Nepal. Methods: MINI was a prospective community intervention study aimed at managing newborn illnesses at household level. Trained field staff conducted a verbal autopsy of all neonatal deaths during the study period. The cause of death was assigned by two pediatricians, and by using InterVA version 5. Cohen's kappa coefficient was calculated to compare the agreement between InterVA and PRVA assigned proximate cause of death, using STATATM software version 16.1. Results: Among 381 verbal autopsies for neonatal deaths, only 311 (81.6%) were assigned one of birth asphyxia, neonatal infection, congenital anomalies or preterm-related complications as the proximate cause of death by both InterVA and PRVA, while the remaining 70 (18.4%) were assigned other or non-specific causes. The overall agreement between InterVA and PRVA-assigned cause of death categories was moderate (66.5% agreement, kappa=0.47). Moderate agreement was observed for neonatal infection (kappa=0.48) and congenital malformations (kappa=0.49), while it was fair for birth asphyxia (kappa=0.39), and preterm-related complications (kappa=0.31); but there was only slight agreement for neonatal sepsis (kappa=0.19) and neonatal pneumonia (kappa=0.16) as specific causes of death within neonatal infections. Conclusions: We observed moderate overall agreement for major categories of causes of neonatal death assigned by InterVA and PRVA. The moderate agreement was sustained for the classification of neonatal infection but poor for neonatal sepsis and neonatal pneumonia as distinct categories of neonatal infection. Further studies should investigate the comparative effectiveness of an updated version of InterVA with the current standard of assigning the cause of neonatal death through longitudinal and experimental designs.