[Development of a screening questionnaire to predict good and poor outcome of lumbar disc surgery.]

The aims were: (1) to investigate the prognostic value of pain history, sociodemographic, psychodiagnostic and medical factors for long-term outcome after lumbar disc surgery and (2) to develop a screening checklist of reliable predictors that distinguish between good and poor outcomes.

In six different spine centers 510 patients were assessed after indication for operation by independent research teams. Most of the patients (n=400) were being operated upon for the first time (group 1), while 110 patients had had previous back surgery (group 2). More than 80% of the patients participated in the follow-ups performed 6 and 12 months later.

During the follow-up period, 19 (4.8%) patients of group 1 and 11 (10%) patients of group 2 had renewed back surgery. The outcomes 12 months postoperatively were: good in 51.5%, moderate in 28.4% and poor in 20.1% for group 1; good in 43.2%, moderate in 32.1% and poor in 24.7% for group 2. In order to identify relevant predictors, the preoperatively obtained data of group 1 patients with a good outcome and those with a poor one were compared. Using multivariate discriminant analysis, 80% of these patients were correctly classified. The most important predictors were found to be: intensity of restricted physical mobility, number of other pain locations, duration of subjectively reduced working capability, and duration of acute back pain. On the basis of this statistical analysis, 11 predictors were selected and converted to scores, reflecting their relative significance. The calculation of a sum score gave an appropriate prediction of 76% for good and 79% for poor outcomes. For group 2 the results were nearly the same.

It is possible to determine for each patient a predictor sum that is prognostic for the individual risk of a poor operation outcome.