IMPROVED SURVIVAL OF STROKE PATIENTS DURING THE 1980S - THE MINNESOTASTROKE SURVEY

Background and Purpose The underlying reasons for the decline in strok e mortality in the United States are not well understood and have been the subject of ongoing debate. This study was undertaken to determine whether survival of hospitalized stroke patients has changed during t he 1980s, thereby contributing to the decline in stroke mortality duri ng that period. Methods For the years 1980, 1985, and 1990, we obtaine d listings of discharge diagnoses from hospitals in the Minneapolis-St Paul metropolitan area and identified all hospitalizations with a dis charge diagnosis code of acute cerebrovascular disease according to th e International Classification of Diseases, 9th Revision. A 50% random sample of men and women aged 30 to 74 years was selected in each surv ey for detailed medical record abstraction. Standardized sets of crite ria for stroke were then used to validate acute stroke events througho ut the 1980s. Each of the three period cohorts of hospitalized stroke patients (1980, 1985, and 1990) was followed for at least 2 years for all-cause mortality end point. Results A total of 1853 patients met mi nimal criteria for acute stroke: 564 patients in 1980, 598 patients in 1985, and 691 patients in 1990. Controlling for age, the odds of deat h within 2 years after stroke were approximately 40% lower in 1990 tha n in 1980. The relative odds of 2-year death in 1990 (versus 1980) wer e 0.65 (95% confidence interval, 0.47 to 0.89) and 0.60 (95% confidenc e interval, 0.42 to 0.85) for men and women, respectively. The improve d survival was evident in the short term (28 days) as well as for stro ke patients who survived that period. Analysis according to stroke sub type revealed that improved survival of ischemic stroke and specifical ly of stroke with no apparent cardioembolic source largely accounted f or the overall trend. The prognosis of stroke patients who were admitt ed in a comatose state has not changed during that decade. Conclusions Despite the absence of any clear major advances in acute stroke thera py, survival of stroke patients substantially improved during the 1980 s. The underlying reasons for this unexpected yet remarkable trend rem ain uncertain but may include improved supportive and rehabilitative c arl of stroke victims as well as a change in the natural history of th e disease.