Geographic variation in lumbar fusion for degenerative disorders: 1990 to 2000.

BACKGROUND CONTEXT: Past studies have shown that proportion of lumbar fusion surgery to all forms of lumbar surgery is variable among geographic regions. At present, no studies have investigated whether fusion outcome is associated with geographic region.

PURPOSE: The purpose of this study was to examine the postoperative complication rate, postoperative mortality rate, hospital length of stay (LOS), hospital routine discharge rate, and total charges associated with surgical care across the geographic regions.

STUDY DESIGN/

SETTING

Retrospective cohort study using national sample administrative data.

PATIENT SAMPLE: The study included 23,143 patients who underwent lumbar spine fusion surgery with a principal diagnosis of lumbar spine disease related to degeneration.

OUTCOME MEASURES: Functional measures included complication rate, mortality rate, and hospital LOS; routine discharge; and total charges for care.

METHODS

Selected variables from the Nationwide Inpatient Sample database were used for comparison across the geographic regions of the South, Midwest, Northeast, and West. Bivariate statistical analyses compared postoperative complication rates, mortality rates, hospital LOS, routine discharge rate, and total charges associated with surgical care across the geographic regions.

RESULTS

Significant differences in routine discharge (p<.001), cauda equina complications (p=.001), LOS (p<.001), and inflation-adjusted charges (p<.001) were found for the South and the West (demonstrated lower routine discharges and higher rates of complications involving cauda equina syndromes) and the Northeast and the Midwest (involved higher LOS than the South and the West but lower reported charges after adjustments for inflation).

CONCLUSIONS

The findings suggest that surgical fusion outcome is associated with regional variations. It is likely that patient selection and physician preferences are associated with these findings. Similar to variations in proportion of lumbar fusion surgery among geographic regions, outcomes for surgical fusions also vary across regions.