How much do the physician review and InterVA model agree in determining causes of death? A comparative analysis of deaths in rural Ethiopia

Background: Despite it is costly, slow and non-reproducible process, physician review (PR) is a commonly used method to interpret verbal autopsy data. However, there is a growing interest to adapt a new automated and internally consistent method called InterVA. This study evaluated the level of agreement in determining causes of death between PR and the InterVA model. Methods: Verbal autopsy data for 434 cases collected between September 2009 and November 2012, were interpreted using both PR and the InterVA model. Cohen s kappa statistic (?) was used to compare the level of chance corrected case-by-case agreement in the diagnosis reached by the PR and InterVA model. Results: Both methods gave comparable cause specific mortality fractions of communicable diseases (36.6 by PR and 36.2 by the model), non-communicable diseases (31.1 by PR and 38.2 by the model) and accidents/injuries (12.9 by PR and 10.1 by the model). The level of case-by-case chance corrected concordance between the two methods was 0.33 (95 CI for ?=0.29-0.34). The highest and lowest agreements were seen for accidents/injuries and non-communicable diseases; with ?=0.75 and ?=0.37, respectively. Conclusion: If the InterVA were used in place of the existing PR process, the overall diagnosis would be fairly similar. The methods had better agreement in important public health diseases like; TB, perinatal causes, and pneumonia/sepsis; and lower in cardiovascular diseases and neoplasms. Therefore, both methods need to be validated against a gold-standard diagnosis of death.