A population-based observational study of intensive care unit-related outcomes. With emphasis on post-hospital outcomes

Abstract

Rationale: Many studies of critical illness outcomes have been restricted to short-term outcomes, selected diagnoses, and patients in one or a few intensive care units (ICUs).

Objectives: Evaluate a range of relevant outcomes in a population-based cohort of patients admitted to ICUs.

Methods: Among all adult residents of the Canadian province of Manitoba admitted to ICUs over a 9-year period, we assessed ICU, hospital, 30-day, and 180-day mortality rates; ICU and hospital lengths-of-stay; Post-hospital use of hospital care, ICU care, outpatient physician care, medications, and home care; and Post-hospital residence location. We explored data stratified by age, sex, and separate categories of geocoded income for urban and rural residents. For Post-hospital use variables we compared ICU patients with those admitted to hospitals without the need for ICU care.

Measurements and main results: After ICU admission there was a high initial death rate, which declined between 30 and 180 days and thereafter remained at the lower value. Hospital mortality was 19.0%, with 21.7% dying within 6 months of ICU admission. Women had higher hospital mortality than men (20.8 vs. 17.8%; P = 0.0008). Among urban residents there was a steady gradient of declining hospital mortality with rising income (P < 0.0001). Mean ICU length of stay was 3.96 days, increasing 0.11 d/yr over the study period (P = 0.001); median ICU length of stay was 2.33 days and did not change over time. In the year after ICU care, 41% were rehospitalized, 10% were readmitted to an ICU, 98% had outpatient physician visits, 96% used prescription medications, and 27% used home care services. Although most of these parameters were statistically higher than for hospitalizations not requiring ICU care, differences were generally small. Among hospital survivors, 2.7% were discharged to chronic care facilities, with 2.5% living in such facilities 3 months later.

Conclusions: Post-hospital medical resource use among ICU survivors is substantial, although similar to that after non-ICU hospitalization. Although the fraction of survivors unable to live independently was small, a larger fraction required home care services. Identifying Post-hospital supports needed by ICU survivors can be useful for policy makers and others responsible for healthcare planning.

Keywords: health resources; intensive care units; long-term care; outcomes assessment; outcomes research.