Small Area Variation in MHS Clinical PracticeObjective: Geographic variation in the delivery of medical services is a well-documented phenomenon in the United States. The identification of the potential sources of variation has significant ramifications for the quality of health care, especially in terms of patient risk, patient choice, and resource allocation. The Center for Health Care Management Studies designed and directed a study to establish variation, if any, of clinical practices in military treatment facilities (MTF) and factors associated with it to indicate mediation strategies. The purpose of this study is to identify variation in clinical practice by MTF and demographic categories for a limited number of specific health care diseases and ailments on a severity-adjusted basis. Medical conditions that were studied include five procedures: (1) coronary artery bypass graft (CABG) and (2) percutaneous transluminal coronary angioplasty (PTCA) with or without a stent for persons with coronary artery disease (CAD); (3) knee arthroscopy; and (4) open and (5) laparoscopic cholecystectomy.
Results: Our evaluation reveals that there is relatively little unexplained variation in the rate of selected procedures among TRICARE Prime enrollees in our study population as assessed by examination of difference in observed versus expected number of procedures at the Parent DMISID level. For example, less than 10 MTFs have expected numbers of CABG and PTCA procedures above or below two standard deviations from the average calculated across all study MTFs. Moreover, it was found that the vast majority of study enrollees, who are receiving the selected procedures, have had prior encounters or have as a principal diagnosis at the time of the procedure clinical conditions that are appropriate indications for having the procedure. In contrast, there is considerably more unexplained variation among MTFs exhibited when examining the rates of knee arthroscopy, a more discretionary procedure. Nearly one-third of the study MTFs have arthroscopy rates that are considerably above or below the expected number of procedures. There are significant differences on use of these procedures between Services affiliated with the MTF.