IMPACT OF A WORKERS COMPENSATION PRACTICE GUIDELINE ON LUMBAR SPINE FUSION IN WASHINGTON-STATE

OBJECTIVES. In the face of escalating medical costs for injured worker s, the Washington State Department of Labor and Industries (L&I), whic h pays for most workers' compensation costs in the state, established guidelines for elective lumbar fusion as part of its inpatient utiliza tion review program. The guidelines were tied to reimbursement strictu res. The authors attempt to assess the effects of these guidelines, wh ich were introduced in November 1988, upon subsequent L&I fusion proce dures. METHODS. Discharge data from the Comprehensive Hospital Abstrac t Reporting System and algorithms using International Classification o f Diseases, Version 9, Clinical Modification diagnosis and procedure c odes were used to identify lumbar surgical cases. Population estimates were from the 1990 US Census Bureau. RESULTS. During the period of ye ars 1987 through 1992, the lumbar fusion rate for the state showed a 2 6% decline compared with a 3% decrease for all lumbar operations. Afte r November 1988, when the guidelines went into effect, the state fusio n rate declined 33%, whereas rates faa nonfusion operations essentiall y were unchanged. The sharpest decline corresponded in time to impleme ntation of the guidelines. Prior to the initiation of L&I guidelines, the proportion of fusions among L&I patients was higher than among non -L&I patients. The opposite was true by the end of 1992, and the L&I p roportion decreased more rapidly than the non-L&I proportion. Time ser ies analysis revealed that both the decline in Washington state lumbar fusion rates and the decline in the proportion of lumbar fusion among L&I patients were statistically significant. CONCLUSIONS. The data su ggest that the L&I lumbar fusion surgery criteria and reimbursement st andards implemented in 1988 contributed to a decline in rates of perfo rming that procedure. The utilization review aspect of the guidelines as well as the process of involving surgeons in the preparation and di ssemination of guidelines also may have been contributory.