Comparative performance of diagnosis-based and prescription-based comorbidity scores to predict health-related quality of life

Objectives: To compare the performance of the health-related quality of life-comorbidity index (HRQoL-CI) with the diagnosisbased Charlson, Elixhauser, and combined comorbidity scores and the prescription-based chronic disease score (CDS) in predicting HRQoL in Agency of Healthcare Research and Quality priority conditions (asthma, breast cancer, diabetes, and heart failure). Methods: The Medical Expenditure Panel Survey (2005 and 2007-2011) data was used for this retrospective study. Four diseasespecific cohorts were developed that included adult patients (age 18 y and above) with the particular disease condition. The outcome HRQoL [physical component score (PCS) and mental component score (MCS)] was measured using the Short Form Health Survey, Version 2 (SF-12v2). Multiple linear regression analyses were conducted with the PCS and MCS as dependent variables. Comorbidity scores were compared using adjusted R2. Results: Of 140,046 adult participants, the study cohort included 7436 asthma (5.3%), 1054 breast cancer (0.8%), 13,829 diabetes (9.9%), and 937 heart failure (0.7%) patients. Among individual scores, HRQoL-CI was best at predicting PCS and MCS. Adding prescription-based comorbidity scores to HRQoL-CI in the same model improved prediction of PCS and MCS. HRQoL-CI+CDS performed the best in predicting PCS (adjusted R2): asthma (43.7%), breast cancer (31.7%), diabetes (32.7%), and heart failure (20.0%). HRQoL-CI+CDS and Elixhauser+CDS had superior and comparable performance in predicting MCS (adjusted R2): asthma (HRQoL-CI+CDS = 20.1%; Elixhauser+CDS = 19.6%), breast cancer (HRQoL-CI+CDS = 12.9%; Elixhauser+CDS = 14.1%), diabetes (HRQoL-CI+CDS = 17.7%; Elixhauser+CDS = 17.7%), and heart failure (HRQoL-CI+CDS = 18.1%; Elixhauser+CDS = 17.7%). Conclusions: HRQoL-CI performed best in predicting HRQoL. Combining prescription-based scores to diagnosis-based scores improved the prediction of HRQoL.