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

Abstract

Purpose: 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.

Materials and methods: 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.

Results: 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.

Conclusions: 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.

Keywords: diagnostic imaging; medical overuse; physician self-referral; reimbursement, incentive; urolithiasis.