Insurance status and mortality in critically ill patients

The association between insurance status and outcome in critically ill patients is uncertain. We aimed to determine if there was an independent relationship between the presence or absence of compensable insurance status and mortality, after admission to the intensive care unit.

We performed a retrospective cohort study in five public hospitals in Victoria, comprising adult patients admitted to the ICU between 2007 and 2012. We obtained data on demographics, severity of illness, chronic health status, insurance category, length of stay (LOS) and mortality. We matched socio-economic indices (collected from the Australian Bureau of Statistics) to postcodes. The primary outcome measured was in-hospital mortality. Secondary outcomes were ICU mortality, and ICU and hospital LOS, measured in days.

We studied 33 306 patients. Compensable patients comprised 21.2% of the study population (7046). Personal private insurance accounted for 13.4% (4451) and Transport Accident Commission insurance for 5.1% (1701) of compensable patients. Unadjusted in-hospital mortality was higher in publicly insured patients (13.4% v 10.6%, P < 0.0001). After adjusting for age, severity of illness, diagnosis and socio-economic status, being a compensable patient in a public hospital ICU was independently associated with a reduction in mortality (odds ratio, 0.73; 95% CI, 0.65-0.80; P < 0.001).

Among ICU patients treated in public hospitals in Victoria, being a compensable patient appears to be independently associated with a reduction in mortality. Further studies are needed to confirm and validate these findings elsewhere in Australia.