Personal, organizational, and market level influences on physicians' practice patterns - Results of a national survey of primary care physicians

BACKGROUND. One of the principal tenets of managed care is that physicians' clinical decisions can be influenced both to improve the quality and consi stency of care and to decrease health care expenditures. Medical decision m aking, however, remains a complex phenomenon and the most important determi nants of physicians' approaches to clinical decision making remain poorly u nderstood. OBJECTIVES. To determine how clinical decisions are associated with individ ual characteristics, practice setting and organizational characteristics, a ttributes of the patient population under care, and the market environment. RESEARCH DESIGN. Cross-sectional, nationally representative survey of patie nt-care physicians. SUBJECTS. Primary care physicians who provide direct patient care at least 20 hours per week. MEASURES. Proportion of physicians who would order a ref erral, diagnostic test, or treatment for 5 clinical scenarios thought to be representative of discretionary medical decisions. RESULTS. Responses were received from 4,825 primary care physicians who car ed for adult patients (Response Rate 65%). The distribution of results for each of the five clinical scenarios demonstrates significant variability bo th within and between physicians. No evidence was seen of a consistent prac tice style across the vignettes (eg, "aggressive" or "conservative"). The o rganizational setting of practice was the most consistent predictor of beha vior across all the clinical scenarios, with the exception of back pain, wh ich was minimally related to any of the environmental factors. When compare d to physicians in solo practice, physicians in all other practice settings were less likely to order a test or referral or pursue treatment. Practice involvement with managed care and measures of financial influences and adm inistrative strategies associated with managed care were minimally and inco nsistently associated with reported physician behaviors. CONCLUSIONS. The ability of managed care to improve the quality and consist ency of care while also controlling the costs of care depends on its abilit y to influence medical decisions. Our findings generally demonstrate that m anaged care has a weak influence on discretionary medical decisions and tha t the influence of managed care pales in comparison to personal and practic e setting influences.