Brief report. Validation study of a verbal autopsy method for causes of childhood mortality in Namibia

Abstract

Verbal autopsy uses a caretaker interview to determine the cause of death. We conducted a study of the major causes of child death in Namibia to determine the validity of this method. A questionnaire, including signs and symptoms of the diagnoses of interest was administered to the caretaker in 135 deaths of children < 5 years old who were identified from hospital records. The 243 diagnoses included malnutrition (77), diarrhoea (73), pneumonia (36), malaria (33), and measles (24). Sensitivity and specificity of various algorithms of reported signs and symptoms were compared to the medical diagnoses. An algorithm for malnutrition (very thin or swelling) had 73 per cent sensitivity and 76 per cent specificity. An algorithm for cerebral malaria (fever, loss of consciousness or convulsion) had 72 per cent sensitivity and 85 per cent specificity, while for all malaria deaths the same algorithm had low sensitivity (45 per cent) and high specificity (87 per cent). For diarrhoea, loose or liquid stools had high sensitivity (89 per cent), but low specificity (61 per cent). Cough with dyspnoea or tachypnoea had 72 per cent sensitivity and 64 per cent specificity. An algorithm for measles (age > or = 120 days, rash) had 71 per cent sensitivity and 85 per cent specificity. The study results suggest verbal autopsy data can be useful to ascertain the leading causes of death in childhood, but may have limitations for health impact evaluation.

Verbal autopsy

“…The validity of physician review of VA has been tested in children and adults, and shown to have reasonable sensitivity and specificity for selected causes of death. 2,11,14,17,21,22,[25][26][27] However, the repeatability of causes of death derived by physician review is low. 28 Although intertobserver agreement is shown to be high in some studies, this may simply reflect consistency in physicians' prior knowledge of the local epidemiology.…”

“…14,17,21,22,25,27,35 All validation studies except one have used causes of death based on medical records as the "gold standard". 25 Most studies have estimated the sensitivity and specificity of VA, but few studies have ast t sessed the agreement in the causetspecific mortality fraction (CSMF) between the gold standard and VA diagnoses.…”

Validity of verbal autopsy for ascertaining the causes of stillbirth

“…6 However, the tool requires validation in countries having different patterns of mortality. 7 Whereas several verbal autopsy validation studies have been performed for infant and early childhood deaths, [8][9][10] only two validation studies for stillbirth have been reported so far. 11,12 Both were retrospective hospital-based studies, one of which had a long recall period and the other combined stillbirths with early neonatal deaths.…”

El uso de la autopsia verbal en el análisis de la salud

“…Por ejemplo, un estudio de validación del diagnóstico de bronconeumonía en niños obtenido mediante autopsias verbales utilizando registros hospitalarios reporta una sensibilidad de 71% y una especificidad de 92% (Mirza et al, 1990). Los algoritmos utilizados para identificar malnutrición muestran sensibilidades y especificidades de más de 70% (Mobley et al, 1996;Snow et al, 1992a); para sarampión sensibilidades entre 71 y 98% y especificidades de entre 85 y 90% (Kalter et al, 1990;Mobley et al, 1996;Snow et al, 1992a). Con relación a la diarrea, tanto la sensibilidad (>70%) como la especificidad (79%) son altas, no así los reportes maternos acerca de la presencia de deshidratación moderada o severa (Chandramohan et ai, 1998a;Kalter et al, 1990).…”