Characteristics in Medicare beneficiaries associated with reoperation after lumbar spine surgery.

STUDY DESIGN: A cohort study was undertaken using medical claims of Medicare beneficiaries.

OBJECTIVES: Factors associated with reoperation after lumbar spine surgery were identified.

SUMMARY OF BACKGROUND DATA: Repeat spine surgery is one outcome measure of surgical success, but little is known about clinical or demographic factors associated with repeat surgery.

METHODS: Medicare beneficiaries who had surgery in 1985 were included in follow-up through 1989. Time between the first operation and a lumbar spine reoperation, death, or end of follow-up period was recorded. Survival analysis (time-to-event) techniques were used to test the association of baseline characteristics with reoperation.

RESULTS: Higher reoperation rates were associated (P < 0.05) with previous back surgery, younger age, recent hospitalization, white race, and diagnosis of herniated disc (compared with other diagnoses). Fusion alone or combined with other procedures did not lower the reoperation rate.

CONCLUSION: Reoperation rates are affected not only by technical factors, but also by demographic and clinical characteristics that are often omitted from reports of surgical case series.