The effect of previous low back surgery on general health status: results from the National Spine Network initial visit survey of patients with low back pain.

Study Design: A cross-sectional study on 18,325 patients with back pain enrolled at first visit in the National Spine Network (NSN) database from January 1998 to April 2000.
Objectives: To examine whether patients who had previous low back surgeries had poorer general health status than patients with no surgery.
Summary of Background Data: Several studies have described the role of psychological abnormalities in patients with chronic low back pain. Some of these patients have had previous spinal surgeries performed. No study has examined the effects of previous low back surgery on the general health status.
Methods: The Short Form Health Survey 36 was administered to the initial visit NSN patients. Of the 18,325 patients enrolled, 3,632 had previous low back surgeries.
Results: Patients who had previous lumbar surgeries fared significantly poorly in all 10 scores of the SF-36 health survey, even after adjustment for confounding factors. Among these patients, decompression achieved significantly higher scores for General Health, Role-Physical, and Mental Component Summary scales. Patients who had decompression as their most recent surgery had higher scores for General Health, Role-Physical, Role-Emotional, and Mental Component Summary scales, when compared to those who had other surgeries. Patients who had instrumentation as their most recent surgery had higher scores for Bodily Pain and Physical Component Summary scores. There is a positive correlation between time since last surgery and the SF-36 outcomes.
Conclusions: Previous back surgery is associated with significantly worse general health status than those without surgery. Among patients who had previous surgeries, decompression seems to exert better effects on SF-36 health status. There is a positive correlation between time since last surgery and the SF-36 outcomes, although the SF-36 scores are significantly lower than those without previous surgery.