Comparing Comorbidity Polypharmacy Score and Charlson Comorbidity Index in predicting outcomes in older trauma patients

Abstract

BackgroundThe Charlson Comorbidity Index (CCI) and Comorbidity Polypharmacy Score (CPS) may potentially risk-stratify older trauma patients more accurately than traditional trauma severity scores. We aim to evaluate if CCI or CPS are better predictors of mortality and discharge venue in such patients. MethodsWe conducted a retrospective study using registry data from two tertiary trauma centres. Patients aged 65 years and above who presented to the emergency departments (EDs) between January 2011 and December 2015 with traumatic injuries were included. Charts were reviewed for demographics, injury mechanism and severity, discharge outcomes, and types of comorbidities and medications used. Primary outcome was overall mortality; secondary outcomes included ED disposition and hospital discharge venue. Discriminatory power of the score(s) were compared using area under the receiver operating characteristic (AUROC) curve. ResultsThere were 2,750 patients, with overall female predominance (56.7%, 1,560/2,750) and median age of 78 years (interquartile range [IQR] 72 to 84 years). Median CCI score was 1 (IQR 0 to 2) and median CPS was 8 (IQR 4 to 12). Overall mortality was 9.4% (259/2,750). Every 1-point increase in CCI score resulted in increased odds of death by 16% (adjusted odds ratio 1.16, 95% confidence interval 1.07 to 1.26, p<0.001). Addition of CCI to the Injury Severity Score (ISS) increased the discriminatory power for mortality (AUROC for ISS = 0.832; AUROC for ISS with CCI = 0.843). Every 1-point increase in CCI was significantly associated with decreased odds of admission to a rehab facility by 8%. CPS did not predict mortality and discharge venue. ConclusionCCI, but not CPS, was a predictor of mortality. A higher CCI was associated with decreased odds of discharge to a subacute facility, likely related to underlying rehabilitation potential. Further studies should be undertaken to explore an integrated scoring system that considers injury severity, comorbidities, and polypharmacy.