Comparing Performance of Comorbidity Indices in Predicting Functional Status, Health-Related Quality of Life, and Total Health Care Use in Older Adults With Back Pain

Secondary analysis of prospective cohort study.Common comorbidity indices were developed to predict mortality and may not be optimal for functional outcomes.Determine how well the Functional Comorbidity Index (FCI) predicts outcomes in older adults with back pain versus the Quan/Charlson and Elixhauser comorbidity indices.We included 5155 adults ≥65 years with new primary care visits for back pain. Comorbidity was measured using diagnosis codes...