Anticipating the Unintended Consequences of Closing the Door on Physician Self-Referral

Abstract

While physician self-referral has been associated with increased health care use, the downstream effects of the practice remain poorly characterized. Accordingly we identified the relationship between urologist self-referral and downstream health care use in patients with urinary stone disease. With urologist self-referral status as the exposure of interest, we performed a retrospective cohort study of Medicare beneficiaries from 2008 to 2010 to evaluate the relationship between self-referral and imaging intensity, risk of surgical treatment and time to surgical treatment for urinary stone disease. We identified dose dependent increases in computerized tomography use with increasing stratum of urologist self-referral. Compared to nonself-referring urologists, computerized tomography use was 1.19 times higher (95% CI 1.07-1.34) in episodes ascribed to intermediate frequency (5 to 9) and 1.32 times higher (95% CI 1.16-1.50) in episodes ascribed to high frequency (10+) self-referring urologists. Self-referral was inversely associated with risk of surgical treatment for stone disease. Specifically, patients treated by intermediate and high frequency self-referring urologists were less likely to undergo surgical treatment than those treated by nonself-referring urologists, with HR 0.84 (95% CI 0.71-0.99) and HR 0.81 (95% CI 0.66-0.99), respectively. We identified no statistically significant between-group differences in time to surgical treatment. Self-referral is associated with increased use of computerized tomography and with decreased use of surgery for stone disease. While policy efforts to further restrict physician self-referral may reduce the use of computerized tomography, they may also result in unintended consequences with respect to patterns of surgical care.