Three-year outcomes for Medicare beneficiaries who survive intensive care

Abstract

Context: Although hospital mortality has decreased over time in the United States for patients who receive intensive care, little is known about subsequent outcomes for those discharged alive.

Objective: To assess 3-year outcomes for Medicare beneficiaries who survive intensive care.

Design, setting, and patients: A matched, retrospective cohort study was conducted using a 5% sample of Medicare beneficiaries older than 65 years. A random half of all patients were selected who received intensive care and survived to hospital discharge in 2003 with 3-year follow-up through 2006. From the other half of the sample, 2 matched control groups were generated: hospitalized patients who survived to discharge (hospital controls) and the general population (general controls), individually matched on age, sex, race, and whether they had surgery (for hospital controls).

Main outcome measure: Three-year mortality after hospital discharge.

Results: There were 35,308 intensive care unit (ICU) patients who survived to hospital discharge. The ICU survivors had a higher 3-year mortality (39.5%; n = 13,950) than hospital controls (34.5%; n = 12,173) (adjusted hazard ratio [AHR], 1.07 [95% confidence interval {CI}, 1.04-1.10]; P < .001) and general controls (14.9%; n = 5266) (AHR, 2.39 [95% CI, 2.31-2.48]; P < .001). The ICU survivors who did not receive mechanical ventilation had minimal increased risk compared with hospital controls (3-year mortality, 38.3% [n = 12,716] vs 34.6% [n=11,470], respectively; AHR, 1.04 [95% CI, 1.02-1.07]). Those receiving mechanical ventilation had substantially increased mortality (57.6% [1234 ICU survivors] vs 32.8% [703 hospital controls]; AHR, 1.56 [95% CI, 1.40-1.73]), with risk concentrated in the 6 months after the quarter of hospital discharge (6-month mortality, 30.1% (n = 645) for those receiving mechanical ventilation vs 9.6% (n = 206) for hospital controls; AHR, 2.26 [95% CI, 1.90-2.69]). Discharge to a skilled care facility for ICU survivors (33.0%; n = 11,634) and hospital controls (26.4%; n = 9328) also was associated with high 6-month mortality (24.1% for ICU survivors and hospital controls discharged to a skilled care facility vs 7.5% for ICU survivors and hospital controls discharged home; AHR, 2.62 [95% CI, 2.50-2.74]; P < .001 for ICU survivors and hospital controls combined).

Conclusions: There is a large US population of elderly individuals who survived the ICU stay to hospital discharge but who have a high mortality over the subsequent years in excess of that seen in comparable controls. The risk is concentrated early after hospital discharge among those who require mechanical ventilation.