Development of a chronic disease indicator score using a veterans affairs medical center medication database

Objective: Develop a chronic disease index that approximates the number of chronic diseases a patient has using a medication database. Methods: An exp ert panel determined whether specific medication classes could be indicativ e of a chronic disease. Those classes identified were incorporated into a c omputer program and then used to screen the medication records of 246 rando mly selected patients to estimate the number of chronic diseases present in each patient. This number was designated as the chronic disease index (CDI ). The CDI was then validated against chart review. The CDI and a measure o f disease severity, the chronic disease score (CDS) also were compared. The sensitivity and specificity of the computer program was analyzed for seven common chronic diseases. Results: The expert panel designated 54 drug clas ses containing medications used to treat chronic diseases. The CDI correlat ed moderately with the number of chronic diseases found via chart review (r = 0.65; P = 0.001) and highly with the CDS (r = 0.81; P = 0.001). The inde x predicted the presence of three common diseases with a sensitivity of gre ater than or equal to 75%, and of six common diseases with a specificity of greater than or equal to 75%. Conclusions: The CDI correlates moderately w ell with the actual number of chronic disease states present. This tool may be useful for researchers when trying to identify patients with specific d iseases and also for risk adjustment. (C) 1999 Elsevier Science Inc.