Older age, aggressiveness of care, and survival for seriously ill, hospitalized adults

Background: Older age is associated with less aggressive treatment and higher short-term mortality due to serious illness. It is not known whether less aggressive care contributes to this survival disadvantage in elderly persons. Objective: To determine the effect of age on short-term survival, independent of baseline patient characteristics and aggressiveness of care. Design: Secondary analysis of data from a prospective cohort study. Setting: Five academic medical centers participating in SUPPORT (Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments). Patients: 9105 adults hospitalized with one of nine serious illnesses associated with an average 6-month mortality rate of 50%. Measurements: Survival through 180 days of follow-up. In Cox proportional hazards modeling, adjustment was made for patient sex; ethnicity; income; baseline physical function; severity of illness; intensity of hospital resource use; presence of do-not-resuscitate orders on study day 1; and presence and timing of decisions to withhold transfer to the intensive care unit, major surgery, dialysis blood transfusion, vasopressors, and tube feeding. Results: The mean (+/- SD) patient age was 63 +/- 16 years, 44% of patients were female, and 16% were black. Overall survival to 6 months was 53%. In analyses that adjusted for sex, ethnicity, income, baseline functional status, severity of illness, and aggressiveness of care, each additional year of age increased the hazard of death by 1.0% (hazard ratio, 1.010 [95% CI, 1.007 to 1.013]) for patients 18 to 70 years of age and by 2.0% (hazard ratio, 1.020 [CI, 1.013 to 1.026]) for patients older than 70 years of age. Adjusted estimates of age-specific 6-month mortality rates were 44% for 55-year-old patients, 48% for 65-year-old patients, 53% for 75-year-old patients, and 60% for 85-year old patients. Similar results were obtained in analyses that did not adjust for aggressiveness of care. Acute physiology and diagnosis had much larger relative contributions to prognosis than age. Conclusions: We found a modest independent association between patient age and short-term survival of serious illness. This age effect was not explained by the current practice of providing less aggressive care to elderly patients.