Variation in death certification of ischemic heart disease in Australia and New Zealand.

This study was designed to test the hypothesis that the between-State variation in death rates from ischemic heart disease may be due in part to variation in the manner in which death certificates are completed or the diagnoses on them are assigned numerical codes. Random samples of 75 doctors who had recently completed a death certificate in an Australian State or in Auckland, New Zealand, as well as all doctors who had recently completed a death certificate in the Northern Territory were asked to participate. They were sent a book of 10 actual case histories and asked to complete a death certificate for each case. Seventy per cent of the doctors returned death certificates (range from 64% to 81%). Each certificate was coded by the Australian Bureau of Statistics (ABS) in the doctor's State of residence, or by the New Zealand Health Statistics Centre for Auckland respondents, and then coded again by the federal office of the ABS in Canberra. There was considerable variation in the codes assigned to each case history but systematic variation large enough to account for the variation in between-State ischemic heart disease death rates was not seen. There was little systematic variation between codes assigned in each State and by the federal ABS office, although a few isolated discrepancies were identified which need attention by the ABS.(ABSTRACT TRUNCATED AT 250 WORDS)