Dissociation of hospitalization and mortality trends for myocardial infarction in the United States from 1988 to 1997

Abstract

PurposeAlthough age-adjusted mortality from myocardial infarction in the United States has declined during the past few decades, changes in the incidence of myocardial infarction are less certain. To address this issue, we evaluated trends in hospitalization for, and in-hospital mortality from, myocardial infarction from 1988 to 1997. MethodsHospitalization rates were determined by age and sex using data from the National Hospital Discharge Survey and the Current Population Survey. Comorbid conditions, complications, use of cardiac procedures, and in-hospital mortality were measured. In-hospital mortality was estimated after adjusting for associated risk factors, complications, use of invasive diagnostic and therapeutic procedures, and length of stay. ResultsAge-adjusted rates of hospitalization for myocardial infarction were 525 per 100,000 in 1988 and 482 per 100,000 in 1997, with a mean annual decline of 0.8% (P = 0.32). Mortality declined from 58 per 100,000 in 1988 to 40 per 100,000 in 1997, a mean annual decline of 4.2% (P = 0.01). During these 10 years, although the median hospital stay for myocardial infarction decreased from 8 to 5 days, the intensity of hospital care increased, including use of angiography from 20% to 31% (P = 0.04) and revascularization from 16% to 31% (P = 0.004). Age-adjusted in-hospital mortality decreased by nearly half, from 7.6% in 1988 to 3.9% in 1997 (P = 0.006). ConclusionDuring the past decade, the decline in mortality from myocardial infarction in the United States has not been accompanied by a decline in hospitalization rate. At the same time, there has been a marked increased in the use of cardiac revascularization.