PRACTICE VARIATION IN THE MANAGEMENT OF PHARYNGITIS - THE IMPORTANCE OF VARIABILITY IN PATIENTS CLINICAL CHARACTERISTICS AND IN PHYSICIANS RESPONSES TO THEM

The objective of this study was to assess whether geographic differenc es in antibiotic-prescribing rates for patients with pharyngitis could be explained by intersite differences in patients' clinical character istics and in how physicians responded to these clinical cues when mak ing decisions. As part of the initial phase of a prospective controlle d trial to improve physicians' diagnostic ability, the authors enrolle d cohorts of consecutive patients seen at staff-model-HMO student heal th services in Pennsylvania and Nebraska. Physicians' decisions whethe r to prescribe antibiotics for 310 consecutive patients presenting wit h pharyngitis to the former and 214 such patients presenting to the la tter at the time of the initial visit were examined. There was a large discrepancy between the antibiotic-prescribing rates at the student h ealth services in Pennsylvania, 106/310, 32.4%, and Nebraska, 156/214, 72.9%. The clinical variables significantly independently associated with treatment at both sites in a logistic regression model were fever , adjusted odds ratio = 2.1 (95% Cl = 1.1, 3.8); exudates, 5.4 (2.8, 1 0); palatine petechiae, 6.5 (1.5, 28); rhinorrhea, 0.46, (0.25, 0.85); and high risk of complications, 3.8 (1.04, 14). There was a significa nt interaction between site and anterior cervical adenopathy, 5.5 (1.6 , 19); and a borderline interaction between site and rhinorrhea, 2.4 ( 0.89, 6.7). Site was not a significant independent predictor of treatm ent, 1.8 (0.45, 6.6.). Practice variation was related to geographic di fferences in patients' clinical characteristics and in how physicians responded to these factors when prescribing antibiotics. How physician s weight patients' clinical characteristics when making decisions may be an important element of their ''practice styles.''