The effects of questionnaire design on the determination of end results in lumbar spinal surgery.

Two hundred and seven patients followed a minimum of 10 years after a single lumbar disc operation were evaluated using 14 different questionnaires that measure surgical outcomes. Dependent on the questionnaire design, the satisfactory outcomes for this population ranged from 97% to 60%, which is statistically significant. The authors conclude that the reported outcomes for lumbar spinal surgery are significantly manipulated by the criteria selected for the assessment of end results.