Inequalities in health in intensive care patients

In order to study the possible association between socioeconomic status (SES) and critical care mortality, we examined a cohort of 847 patients over 14 years of age, as they were consecutively admitted to three general intensive care units (ICUs). The patients with low SES (social classes IV and V according to the British Registrar General's classification) were older (62.0 v 58.5 years old, p less than 0.0001) and showed a higher ICU mortality (odds ratio (OR) = 1.61, p = 0.0204) and severity of illness on admission (mean Simplified Acute Physiology Score [SAPS] 9.9 vs 8.7, p = 0.0002) than patients with high SES (social classes I-III). The initial severity of illness differential was detected both in patients admitted from the emergency area and in patients admitted from the general hospitalization ward, suggesting the existence of some kind of preselection procedure related to the SES of the patient. The stepwise logistic regression analysis identified as independent predictive variables of ICU mortality therapeutic effort (measured with the Therapeutic Intervention Scoring System [TISS]), SAPS score, age and hospital, but not SES. The TISS/SAPS ratio according to origin of patients (emergency/general wards) was comparable in the high and low SES. We conclude that there is an inverse relationship between SES and ICU mortality. The mortality excess in the low SES patients is largely accounted for by the covariates of the low SES (especially their high age and severity of illness on admission). There is no evidence of a different relative therapeutic effort according to the SES.