Abstract 3878: The Validity of the Charlson Comorbidity Index in Predicting Survival Following Permanent Pacemaker Implantation: A Population-Based Cohort Study
Objective: To examine the validity of the Charlson comorbidity index (CCI) in predicting long-term survival after permanent pacemaker (PPM) implantation in a population-based cohort.
Methods: Using the resources of the Rochester Epidemiology Project, we conducted a population-based cohort study of all adult patients in Olmsted County with PPM implanted from 1975 to 2005. The CCI includes 19 comorbid diseases weighted on the basis of their association with mortality and was derived from ICD-9 codes from an administrative database. Patients were grouped into 4 categories based on quartiles of their CCI score. Survival curves were estimated by the Kaplan-Meier method. The association between each quartile of CCI and long-term survival was examined by Cox regression analysis.
Results: Over a 30-year period, 1146 adult patients underwent PPM placement. The mean age was 76 ± 12.6 years; 53% were female. The median weighted CCI was 3 (range 0 to 19). Five-year survival was 84.5%, 59.5%, 50.1%, and 29.6% for patients with CCI of 0–1, 2–3, 4–6, and ≥7, respectively (p<0.0001). After adjusting for age, male gender, and implant year the HR for mortality by CCI was 1.0, 1.8, 2.29, 3.96 for CCI of 0–1, 2–3, 4–6, and ≥7, respectively (p<0.001).
Conclusions: The Charlson comorbidity index is a valid and strong predictor of survival after PPM implantation in a population-based setting. This index can be used to guide clinical decision making and to compare outcomes between treatment groups in nonrandomized studies of patients with PPM by allowing adjustment for comorbidities. Patients with the most comorbidities via CCI had ~300% risk of mortality compared to patients with the lowest CCI.