Accuracy of death certificates in bronchial asthma. Accuracy of certification procedures during the confidential inquiry by the British Thoracic Association. A subcommittee of the BTA Research Committee.

The Research Committee of the British Thoracic Association conducted a confidential inquiry into death from asthma in adults aged 15-64 years resident in the West Midland and Mersey Regions during 1979. Death certificates recording the word asthma were received for 153 persons. The International Classification of Diseases code for the cause of death was obtained from the Office of Population Censuses and Surveys. Information about the patients, their illness, and their death was obtained by interviews, questionnaires, and inspection of patients' records. A panel of three physicians assisted by a pathologist assessed the clinical and, where applicable, the necropsy findings to ascertain whether bronchial asthma was the true cause of death. Of 147 assessable patients, 89 were considered by the panel to have died from asthma. In 77 of these cases the death certificates were correctly coded, whereas in 12 (13%) death was considered to have been wrongly attributed to another cause (falsely negative). Twenty four deaths on the other hand were considered to have been wrongly attributed to asthma (falsely positive). From this it appears that the total number of 101 certificates recording death from asthma represents a net overestimate of 13%. Accuracy was highest in the youngest age group. There were few discrepancies between the assessment of the panel and certified cause of death when a necropsy had been performed. The most common error (17% of all certificates) was failure to follow the procedure advised for completion of death certificates. This usually occurred when patients suffered from two or more conditions, or when death was sudden and necropsy was not performed.