[Asthma-related mortality in the city of Rosário]

Accuracy of death certification and registration have been investigated in many countries because death certificates constitute the unavoidable source for studying asthma mortality. The purposes of this study were: 1) to assess the reliability of official registration of asthma death certification and 2) to describe the percentage of asthma deaths occurring outside-hospital in Rosario during 1988. All death certificates from Rosario residents over 5 years old, in which appeared the word asthma or derivatives, were studied. The asthma mortality rates from 1981 to 1989 were obtained from the "Official annual publication". The diagnosis of asthma was written somewhere on 45 certificates; but 30 certificates were interpreted as asthma being the most appropriate diagnosis and could then be coded as the cause of death. These 30 asthma related deaths occurred at the mean age of 59.23 yrs +/- 17.23 (SD), range 12-84 yrs. Twenty-two deaths out of the total of 30 occurred in an out-hospital setting (73%). Among the 30 cases, 8 subjects (aged 63.0 yr +/- 12.38) died in hospital. There was no difference between the age, sex and the death place. Autopsy was performed in only one case of 12 years old. In other 3 cases, asthma was confirmed as the cause of death through the evaluation of case records and the confidential information collected from close acquaintances. The mean asthma mortality rate from 1981 to 88 in Rosario was 5.69 +/- 1.06/10(5), and this value was significantly higher than the death rate calculated by this study (3.46/10(5); p = 0.0005, T test for one sample). The difference probably originated in the false positive certificates often related to procedures in the General Registrar Office. In other words, there was an official overestimation of asthma deaths. This was the first description of the high percentage (73%) of asthma related deaths occurring in the out-hospital setting. Finally, even when death certificates should require a further and exhaustive assessment, asthma mortality rates in Rosario might be regarded as of great concern.