Fig. 2

Kaplan-Meier curves for ICU and hospital mortality stratified by sex and frailty status. Kaplan-Meier curves evaluating the cumulative incidence of mortality stratified by sex and frailty status (CFS < 5 = non-frail; CFS > = 5 = frail) in the matched sample for a ICU mortality and b hospital mortality. p values calculated using stratified log-rank test, stratified on propensity score quintiles. There is a lower number of patients at risk in the hospital mortality curve because patients that were still in hospital at the time of data extraction were excluded from this analysis