Relationship between rates and outcomes of operative treatment for lumbar disc herniation and spinal stenosis

Background Population-based variations in rates of operations for the treat ment of lumbar disc herniation and spinal stenosis are well known, This var iability may occur in part because of; differences in the threshold at whic h physicians recommend an operation, reflecting uncertainty about the optim um use of an operative procedure, To the best of our knowledge, no previous reports have indicated whether differences in population-based rates of op erative treatment are associated with patient outcomes. Methods:The Maine Lumbar Spine Study is an ongoing prospective study of 655 patients who had a herniated lumbar disc dr spinal stenosis, The patients were enrolled by their physicians, who provided baseline demographic and tr eatment-related data. The patients completed baseline and follow-up questio nnaires that focused On symptoms, function, satisfaction, and quality of li fe. Small-area variation analysis was used to develop three distinct so-cal led spine service areas in Maine. The outcomes (usually at four years; mini mum, two years) were compared among these areas, in which a total of 250 pa tients had been managed operatively and had answered questionnaires. Results: Population-based rates of operative treatment derived from state,v ide data that had been collected over five years in the state of Maine rang ed from 38 percent below to 72 percent above the average rate in the state (a greater than fourfold difference). The outcomes for the patients who had been managed by surgeons in the lowest-rate area were superior to those fo r the patients in the two higher-rate areas. Seventy-nine percent (fifty-se ven) of seventy-two patients in the lowest-rate area had marked or complete relief of pain in the lower extremity compared with 60 percent (eighteen) of thirty patients in the highest-rate area. The improvements in the Poland disability score (p less than or equal to 0,01), quality of life (p less t han or equal to 0,01), and satisfaction (p less than or equal to 0.05) were significantly greater among the patients in the lowest-rate area. The pati ents in the higher-rate areas generally had;less severe symptoms and findin gs at baseline than those in the lowest-rate area did. Conclusions: Higher population-based rates of elective spinal operations ma y be associated with inferior outcomes. This variability is possibly relate d to differences in physicians' preferences with regard to recommending an operation and in their criteria for the selection of patients, Physicians c annot assume that their outcomes will be the same as those of others, and t herefore they need to evaluate their own results.