PROFILING PHYSICIAN PRACTICE PATTERNS USING DIAGNOSTIC EPISODE CLUSTERS

Health plans and providers need to profile current practice patterns t o understand better the resources used in managing medical conditions. A profiling system is presented that groups International Classificat ion of Diseases (ICD-9-CM) codes into 125 diagnostic clusters based on clinical homogeneity with respect to physician treatment response. Fo r each diagnostic cluster, diagnostic episode clusters (DECs) are form ulated. A DEC links all services incurred in treating a patient's medi cal condition within a specific period of time. Each DEC is marked wit h a severity-of-illness, comorbidity, and age indicator. To test the v alidity of the diagnostic cluster methodology, claims were analyzed fr om a preferred provider organization (PPO) and an independent practice association (IPA). PPO and IPA DEC charges and utilization were compa red with t-tests. Physician practice patterns differed based on patien t severity of illness, comorbidities, and age. Both PPO and IPA physic ians delivered significantly more resources to patients in higher seve rity-of-illness categories. PPO physicians generally treated older pat ients with more resources than younger patients. Patient age did not h ave the same impact on IPA physicians' practice patterns. IPA physicia ns' average treatment pattern was about 22% less expensive than that o f PPO physicians. IPA physicians decreased average expenses by reducin g hospital days by about 73% (P < 0.01) and hospital outpatient visits by about 89% (P < 0.01) compared to the rates of PPO physicians. Ambu latory services among IPA physicians were not significantly higher tha n rates for PPO physicians. The DEC methodology is a valid approach fo r profiling patterns of treatment. The style of medicine in the IPA wa s less hospital intensive and, consequently, less expensive than that practiced by PPO physicians. PPO physicians also had greater practice pattern variations than IFA physicians.