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Study Design. Retrospective review of prospective data.

Objective. Determine whether patient reported outcome (PRO) data collected prior to lumbar discectomy predicts achievement of a minimal important difference (MID) after surgery. Compare ability of PRO and clinical information to predict achievement of MID in short term follow-up after discectomy.

Summary of Background Data. We investigated the ability of patient reported outcomes measurement information system (PROMIS) and clinical factors at the preoperative time point to determine patients achieving MID after surgery.

Methods. PROMIS physical function (PF), pain interference (PI), and depression (D) scores were assessed at evaluation and follow-up for consecutive visits between February, 2015 and September, 2017. Patients with preoperative scores within 30 days prior to surgery and with scores 40 days or more after surgery who completed all PROMIS domains were included yielding 78 patients. MIDs were calculated using a distributionbased method. A multivariate logistic regression model was created, and the ability to predict achieving MID for each of the PROMIS domains was assessed. Cut-off values and prognostic probabilities were determined for this model and models combining preoperative PROMIS with clinical data.

Results. Preoperative PROMIS scores modestly predict reaching MID after discectomy (areas under the curve [AUC] of 0.62, 0.68, and 0.76 for PF, PI, and D, respectively). Preoperative cutoff scores show patients who have PF and PI scores more than 2 standard deviations, and D more than 1.5 standard deviations worse-off than population mean are likely to achieve MID. The combination of PROMIS with clinical data was the most powerful predictor of reaching MID with AUCs of 0.87, 0.84, and 0.83 for PF, PI, and D.

Conclusion. PROMIS scores before discectomy modestly predict improvement after surgery. Preoperative PROMIS combined with clinical factors was more predictive of achieving MID than either clinical factors or PROMIS alone.

Key words: herniated lumbar disc, lumbar discectomy, patient reported outcome, patient reported outcomes measurement information system.


Originally published in SPINE: March 1, 2019 - Volume 44 - Issue 5 - p 325-333 doi: 10.1097/BRS.0000000000002823