Abstract 85: Trends In Hospital Readmission Rates among Older Adult Survivors of Mitral Valve Surgery

Abstract

Background: While several studies have shown declining mortality rates after mitral valve surgery (MVS) in older adults, less is known about changes in experience among survivors. The purpose of our study was therefore to determine hospital readmission rates and days spent in the hospital (after index admission) in patients who survived mitral valve surgery up to one year. Methods: Inpatient Medicare data was used to identify 100% of Fee-for-Service patients ≥65 years of age who underwent mitral valve surgery between 1999 and 2010 and survived to one year (N=146,877). We used proportional hazards regression to analyze the all-cause post-MVS readmission rate in each year, number of days spent in the hospital (after index admission), and readmission rates by subgroups of age (65-74, 75-84, ≥85), sex, and race (black, white, other). Results: The overall one year post-MVS readmission rate among survivors of MVS decreased over time (49.5% to 46.9%, P =0.0029, for trend) (Figure). Mean number of hospital days per post-MVS hospitalization decreased as well (6.2 to 5.3, P<0.01). The readmission rate among survivors was highest in oldest patients, but declined in all age subgroups over time (65-74: 47.4% to 44.4%; 75-84: 51.4% to 49.2%, ≥85: 56.4% to 50.0%, all P<0.01). There were declines in women and men (women: 51.7% to 50.8%, P<0.01; men: 46.9% to 43.0%, P<0.01), and in whites and patients of other race, but not in blacks (whites: 49.0% to 46.2%, P<0.01; other: 55.0% to 48.9%, P<0.01; blacks: 58.1% to 59.0%, P=0.1823). Conclusions: Among older adults who survive MVS at one year, fewer than half are readmitted to the hospital. There has been a modest decrease in hospitalization rate and mean hospital days over time, although significant variations among subgroups deserve further study.