An adaptation of Charlson comorbidity index predicted subsequent mortality in a health survey

The Catalan Health Interview Survey Follow-up Study analyzed survival differences according to comorbidity, using an adaptation of the Charlson's index.

Vital status was ascertained by record linkage with death certificates 5 years after interview. Three thousand one hundred five men and 3,536 women aged 40-84 years old were included in the analysis. Proportional hazards models with age as time scale were used to calculate relative risk (RR) and 95% confidence interval adjusted for potential confounders.

The adjusted RR of death in men was 1.02 (0.73-1.41) for a comorbidity index of 1-2; the RR was 1.51 (1-2.30) for an index of 3-4, and 2.64 (1.43-4.89) for an index of >4 composed to an index of 0. In women, for the same comorbidity index categorization, the RR of death were 0.83 (0.55-1.24), 1.71 (1.09-2.72) and 2.65 (1.47-4.77).

This result confirms the relation between comorbidity and the risk of death based on a comorbidity index that takes into account severity and number of self-declared chronic diseases with mortality.