Validation study of cause of death statistics in Cape Town, South Africa, found poor agreement
Burger EH., Groenewald P., Bradshaw D., Ward AM., Yudkin PL., Volmink J.
Objective: The validity of the underlying cause of death on death notification forms was assessed by comparing it to the underlying cause determined independently from medical records. Study Design and Setting: Retrospective study of 703 deaths in two suburbs of Cape Town, South Africa. Two medical doctors completed a medical review death certificate to validate the registration death certificate for each decedent. Agreement, sensitivity, and positive p redictive value were measured for underlying causes of death using the World Health Organization (WHO) mortality tabulation list 1. Results: Agreement was poor, with only 55.3% (95% confidence interval [CI]: 51.7, 59.0) of diagnoses matching at WHO mortality tabulation list 1 level. Validity of reported causes of death was poor for HIV, cardiovascular diseases, and diabetes. With correct reporting, the cause-specific mortality fraction for HIV increased from 11.9% to 18.3% (53.6%; 95% CI: 36.9, 77.6), for ischemic heart disease from 3.3% to 7.3% (121.7%; 95% CI: 53.5, 228.7), and for hypertensive diseases from 3.3% to 5.7% (73.9%; 95% CI: 14.4, 167.8). For diabetes, the mortality fraction decreased from 6.0% to 2.3% (-64.3%; 95% CI: -77.1, -37.8) and for ill-defined deaths from 7.4% to 2.3% (-69.2%; 95% CI: -81.0, -51.6). Conclusion: Current cause-specific mortality levels should be cautiously interpreted. Death certification training is required to improve the validity of mortality data. © 2012 Elsevier Inc. All rights reserved.