The Hidden Influences: Psychological Drivers of Medical Practice Variation

<b>Background:</b> Previous research showed that the majority of the variation in providers' practice patterns is unexplained by patient, physician, and primary care practice characteristics. This study assessed physicians' personal behavioral characteristics as explanatory components of medical practice variation (MPV). <b>Methods:</b> In this cross-sectional study, primary care physicians from Clalit Health Services in southern Israel were interviewed using validated surveys assessing risk-taking, tolerance for ambiguity, stress due to uncertainty, fear of malpractice, and empathy. We analyzed how much these traits explained MPV compared to patient, physician demographic, occupational, and practice characteristics using generalized linear mixed models and Nakagawa's R². <b>Results:</b> Of the 160 physicians approached, 146 (91.3%) participated. The median practicing time was 22 years; 48% were male, with a median age of 49. The median number of patients per practice was 1135. Overall, 40.4% of MPV was explained, mostly by patient characteristics (18.9%), practice characteristics (10.2%), and physician demographics (8.3%). Physician behavioral traits explained only 2.3%. <b>Conclusions:</b> Personal behavior characteristics explain a minority of MPV, leaving 60% of the MPV unexplained. This suggests either limitations in survey assessments or that these traits are not key drivers of MPV.