Figure 3. Charlson Comorbidity Index Scores.

A, The adjusted hazard ratio showed that patients with the least comorbidity (Charlson comorbidity index = 0) were 2.3 times more likely to experience postoperative delirium after receiving heavier sedation levels than after receiving lighter sedation levels. B, Risk estimates for in-hospital postoperative delirium by treatment group and the associated 95% confidence intervals. Sample sizes (incident cases/total cases) are indicated in eTable 1 in Supplement 2. B, The difference in delirium risk after heavier and lighter sedation levels was not significant in patients with greater preoperative comorbidity. The dashed horizontal line indicates a 36.5% risk of in-hospital postoperative delirium, which was the estimated overall risk from the entire STRIDE sample. C, Percentage of patients stratified by Charlson comorbidity index score.