|
Article Excerpt
Over the last two decades, escalating health care costs in the United States have led to sweeping reforms in reimbursement for physician services (The Omnibus Budget Reconciliation Act of 1989; Health Care Financing Administration 1991). The overall effect of these reforms has been to increase compensation for outpatient evaluation and management, while decreasing reimbursement for many surgical procedures (Litwin, Sachet, and Cohen 1993; Goluboff and Olsson 1994). These changes in reimbursement have compelled surgeons to seek alternative sources of revenue in order to maintain their income (Pham et al. 2004). Among urologists, lithotripsy for the treatment of urinary stones has served as one such economic resource (Lotan et al. 2004).
Technological advances have improved the efficiency and decreased the morbidity of stone surgery, allowing more and more procedures to be done in the outpatient setting (Pearle, Calhoun, and Curhan 2005). The profitability of lithotripsy stems, in part, from the unique financial structure of the freestanding ambulatory surgery centers (ASCs) and lithotripsy centers in which many stone surgeries are currently performed. As the provision of lithotripsy services is exempted from the federal statute prohibiting physician self-referral (American Lithotripsy Society et al. vs. Tommy G. Thompson 2002), urologists can refer and treat patients at an ASC or lithotripsy center in which they are invested. Physicians with ownership interest in these centers collect not only a professional fee for the services provided, but they also share in their facilities' profits. Indeed, over the last decade urologists' financial interests in ASCs have increased from 12 to 21 percent, and the proportion of U.S. urologists invested in a lithotripsy center has risen from 36 percent to an estimated 54 percent (Gee et al. 1998; O'Leary et al. 2002).
While there are data to support medical therapy and observation for many patients with urinary stones (Hollingsworth et al. 2006), a variety of clinical factors may influence a urologist's decision to perform surgery, and the ultimate decision for intervention is left to the discretion of the surgeon. Thus, the potential exists for the perversion of those incentives associated with physician ownership. Specifically, urologists with investment in an ASC may be driven by financial pressures to relax their indications for treatment, which would manifest as higher stone surgery rates (McGuire and Pauly 1991; McGuire 2000). With this in mind, we characterized use of stone surgery among urologists as they relate to their ownership status. The results of this analysis have relevance to the policy debate surrounding federal Anti-Kickback Statute safe harbors and Stark Law definitions that permit physician investment in ASCs.
METHODS
Subjects and Databases
For this study, Florida data from the Healthcare Cost and Utilization Project's State Ambulatory Surgery Databases (SASD) were used. The SASD captures 100 percent of surgeries in a given year performed on the same day in which patients are admitted and released (Healthcare Cost and Utilization Project 2008). Its completeness has been validated through alternative sources of comparative data (Busch and Steiner 2007). Abstracted cases were restricted to years 1998 through 2002. After this time period, a change in the surgeon identifier supplied by the data source occurred, which did not conform to the documented pattern, and it was impossible to track physicians across years beyond 2002.
Florida data were chosen primarily for three reasons. First, Florida was one of only four participating states in the SASD that captured data allowing us to follow individual physicians across discharges throughout the study interval. Second, Florida requires no Certificate of Need review before the establishment of an ASC (Health Council of South Florida 2008). Therefore, the competition between hospital-based surgery centers and freestanding ASCs is largely unregulated by the State. Third, Florida is located within the geographic region of the United States with the highest age-adjusted prevalence of urinary stones (Stamatelou et al. 2003), making it useful for assessing their surgical treatment.
The study cohort was identified from the SASD files using Physicians' Current Procedural Terminology codes for those surgical procedures used in the definitive treatment of urinary stones, including percutaneous nephrolithotomy (50080, 50081, 50130, or 50561), shockwave lithotripsy (50590), ureteroscopy (52320, 5232,5, 52330, 52335, 52336, ,52337, ,52351, ,52352, or 52353), and conventional extraction (50060, 50065, 50070, 50075, 50610, 50620, or 50630). Ancillary procedures nonspecific for stone therapy, including placement of a percutaneous nephrostomy tube (50040, 50398, or 52334) or a ureteral stent (52332), were also included if there was a concomitant diagnosis of urinary stone disease based on International Classification of Disease, 9th Revision diagnosis codes (270.0, 271.8, 274.11,592.0, 592.1, or 592.9). By this algorithm, a total of 104,018 discharge records were abstracted, during 36.7 percent of which multiple stone surgeries were performed in the same setting. Using the SASD's surgeon identifier, we then aggregated across discharges...
|
