The basis for interview diagnosis

Certain diseases have characteristic symptoms and signs that, in association often form a relatively distinct clinical syndrome. The objective of an interview based diagnosis is to identify such medical syndromes using information about the illness elicited from relatives, and the approach is most useful when the characteristic symptoms and signs of the disease are sufficiently distinctive to differentiate the disease of interest from other conditions with which it might be confused. In essence the interview attempts to replicate elements of a conventional medical history used to establish a differential diagnosis (i.e., a list of conditions consistent with a patient's symptoms and signs). However, unlike a physician's diagnosis, the interview may not establish a definitive diagnosis because there is no confirmatory information derived from physical examination by a trained health professional, nor information from medical investigations, laboratory tests or autopsy. There is, therefore, inevitable uncertainty in the accuracy of verbal autopsy diagnosis.

There are only a limited number of diseases that present sufficiently distinct syndromes to be potentially suitable for verbal autopsy diagnosis. In children, these include acute conditions such as neonatal tetanus, prematurity/low birth weight and birth injury, measles, diarrhoea/dysentery, acute lower respiratory infection (ALRI), pertussis, meningitis, and injury [1]. However, malaria and chronic conditions such as tuberculosis (TB), nutritional deficiency and AIDS present serious difficulty in diagnosis [1]. The main focus of research has been on diseases that constitute common causes of morbidity and mortality amenable to prevention or treatment.