Impact of two different comorbidity measures on the 6-month mortality of critically ill cancer patients

Abstract

To evaluate the impact of two different comorbidity measures on the 6-month mortality of severely ill cancer patients. Prospective cohort study in a ten-bed oncological medical-surgical intensive care unit (ICU). A total of 772 consecutive patients were included over a 45-month period. The mean age was 57.6+/-16.4 years, and 642 (83%) patients had solid tumors. Data were collected on admission and during ICU stay. Comorbidities were evaluated using the Charlson Comorbidity Index (CCI) and the Adult Comorbidity Evaluation (ACE-27). The ICU, hospital, and 6-month mortality rates were 34%, 47%, and 58%, respectively. The most frequent comorbidities were hypertension (33%), diabetes mellitus (8%), and chronic pulmonary disease (7%). There were important differences between the two indices regarding the comorbidity evaluation. Using the ACE-27, 389 patients (50%) had comorbid ailments that were classified as mild (31%), moderate (14%), and severe (5%) according to the comorbidity severity. According to the CCI, 212 patients (27%) had a comorbidity, and their median score was 1 (1-2). In the multivariable Cox proportional hazard models only the presence of a severe comorbidity by the ACE-27 was associated with increased mortality. The CCI was not independently associated with the outcome. Other outcome predictors were older age, poor performance status, active cancer, need of mechanical ventilation, and severity of acute organ failures. Severe comorbidities must be considered in the outcome evaluation of ICU cancer patients. The ACE-27 seems to be a useful instrument for prognostic assessment in this population.