Gender Disparities in Procedure Use for Acute Myocardial Infarction in the United States, 1995-1997
Gender disparities in procedure use for acute myocardial infarction (AMI) have been well documented in selected populations in the 1980s and early 90s. However, little is known about recent trends in disparities in the general population. Therefore we conducted a series of cross-sectional analyses of data from the Nationwide Inpatient Sample for years 1995 through 1997 to compare rates of catheterization, angioplasty and coronary artery bypass grafting (CABG) performed prior to discharge for acute myocardial infarction in men vs. women. The NIS includes data (including demographics, diagnoses and procedures) on all discharges from over 900 representative civilian hospitals in 22 states. We identified 425,236 discharges with AMI (ICD9 code 410) as the first listed diagnosis during 1995-97. The cohort was 39% female (mean age 71.7) and 61% male (mean age 64.4). From 1995 to 97, catheterization rates increased in women (38.8% to 41.8%)and men (49.7% to 52.4%) as did rates of angioplasty (women 17.1% to 19.9%, men 23.0% to 26.6%) and CABG (women 8.3% to 8.7%, men 11.9% to 12.4%) After adjusting for age, race, and comorbidities, women were less than men to undergo catheterization in 1995 (odds ratio [OR] 0.85, 95% confidence interval [CI] 0.83-0.87), 1996 (OR 0.85, 95%CI 0.83-0.87), and 1997 (OR 0.87 95%CI 0.85-0.87). This gender disparity was even greater among adults aged 65 and older (adjusted OR 0.70, 95%CI 0.68-0.72 in 1995 and 96; and 0.71, 95%CI 0.69-0.72 in 1997). Women were also less likely to undergo CABG (adjusted OR 0.72, 95%CI 0.70-0.74 in 1995, 96 and 97). Among patients who underwent catheterization, women remained less likely to go on to CABG than men (adjusted OR 0.77, 95%CI 0.75-0.79). In contrast,women were only slightly less likely to undergo angioplasty (adjusted OR 0.93, 95%CI 0.91-0.94) and, once catheterized, were actually more likely to go on to angioplasty (adjusted OR 1.03, 95%CI 1.01-1.05). While procedure use for AMI is rising for men and women, these recent nationwide data suggest that women remain much less likely to undergo catheterization or CABG, but about equally likely to undergo angioplasty.