Study design: Prospective longitudinal cohort study with two-year follow up.

Objective: To define the standard outcome measures that describe a patient’s subjective outcome following elective spinal surgery. What constitutes a clinically important change in outcome is not well understood and few studies have addressed this issue.

Subjects: 193 patients undergoing elective spinal surgery (110 discectomy, 72 spinal decompressions and 11 other procedures) Average age 48 years.

Outcome measures: Oswestry disability index (ODI), Low back outcome score (LBO), Visual analogue score (VAS) and patient subjective assessment of outcome as Excellent, Good, Fair and Poor.

Results: There were 100 Excellent results, ODI 54 pre and 19 post. 62 Good results ODI 53 pre and 29 post. The 18 Fair results started with an ODI of 63 and improved to 51. The 13 Poor results started with an ODI of 66 and ended with 61. Similar changes occurred in VAS and Low back outcome score. An excellent outcome for discetomy, ODI reducing from 57 to 13 was different to an excellent outcome for a decompression, where the ODI changed from 54 to 26.

Conclusion: Generic spinal outcome scores are the current measurement tool of clinical change. Clinically significant change as perceived by the patient may be different for different conditions. Only a Poor outcome was associated with an ODI change of less than 10 points.