Preoperative PROMIS Scores Predict Postoperative Outcomes in Lumbar Spine Surgery Patients

Joseph E. Snavely, MD; Joseph A. Weiner, MD; Daniel J. Johnson, MD; Wellington K. Hsu, MD; Alpesh A. Patel, MD, FACS


Spine. 2021;46(17):1139-1146. 

In This Article

Abstract and Introduction


Study Design: Retrospective case series.

Objective: Our objective was to examine the ability of preoperative Patient-reported Outcomes Measurement Information System (PROMIS) scores to predict postoperative achievement of a minimum clinically important difference (MCID) in outcome scores following lumbar spine surgery.

Summary of Background Data: PROMIS is a computer adaptive testing system that has been validated in spine surgery patients. PROMIS allows for more efficient and personalized data collection compared to legacy assessment tools.

Methods: A total of 138 patients who underwent lumbar spine surgery at a single institution completed PROMIS Physical Function (PF) and Pain Interference (PI) scores preoperatively and at 3, 12, and 24 months postoperatively. Univariate and multivariate analyses of PROMIS scores and clinical factors were performed. Receiver-operating characteristic curves were calculated to determine the ability of preoperative scores to predict postoperative achievement of an MCID of 8. PF and PI t score MCID achievement threshold values with 90% specificity were calculated.

Results: Preoperative PROMIS PF and PI scores were significantly correlated to achievement of postoperative MCID after multivariate analysis. Patients with worse preoperative scores were more likely to achieve MCID. Preoperative PF and PI scores showed strong predictive value in determining ability to achieve postoperative MCID with respective area under the curve of 0.85 and 0.82. A preoperative PF threshold T-score of 31.6 had a 64% chance of achieving postoperative MCID, while a preoperative PI threshold t score of 67.8 had an 86% chance of achieving postoperative MCID.

Conclusion: Preoperative PROMIS PF and PI scores predicted improvement in postoperative PROMIS scores in lumbar spine surgery patients as worse preoperative scores correlated to improved PROMIS scores postoperatively. The calculated threshold t scores showed the ability to predict improvement in postoperative PROMIS scores. Preoperative PROMIS data may be useful in surgical decision-making and improved patient education regarding postoperative outcomes.

Level of Evidence: 4


The Patient-reported Outcomes Measurement Information System (PROMIS) computer adaptive testing (CAT) system is a more efficient and personalized data collection tool compared to other legacy assessment measures used in spine surgery patients.[1,2] Utilizing adaptive techniques, such as item response theory, the PROMIS instruments have shown effective and timely data collection with decreased question burden.[2–4] Previous studies have validated PROMIS for use in the spine surgery patient population through correlation with traditional "criterion standard" outcome tools such as the Oswestry Disability Index (ODI), Short Form-12 (SF-12), and visual analog scale (VAS) leg and back scores, while demonstrating no significant differences in granularity or floor and ceiling effects.[3–6] Shorter, responsive assessment tools can improve outcomes research in spine surgery patients and PROMIS effectively meets these criteria as suggested by its increasing utilization in the spine literature.[7,8]

Preoperative baseline patient-reported outcomes (PROs), as well as other patient-specific factors, have shown the ability to predict post-surgical outcomes in spine surgery patients utilizing legacy measures, but there is sparse literature examining the predictive ability of PROMIS tools in this patient population.[9] Rubery et al[10] showed worse baseline PROMIS scores to be a predictor of increased short-term postsurgical minimum clinically important difference (MCID) achievement in lumbar discectomy patients. Patel et al[11] found worse preoperative PROMIS scores in patients undergoing transforaminal lumbar interbody fusion (TLIF) to be predictive of less improvement in postoperative scores up to 1 year after surgery. The predictive ability of baseline PROMIS scores has also been demonstrated in the orthopedic surgery literature including total shoulder arthroplasty, anterior cruciate ligament reconstruction, foot and ankle, and hand surgery patients.[12–16]

To our knowledge, there are currently no studies examining the predictive ability of preoperative PROMIS scores on long-term achievement of postoperative MCID in spine surgery patients. The MCID is a measure of the minimum improvement in patient-centered outcome scores that is determined to be clinically beneficial by a patient following treatment.[17] Hung et al previously defined a median MCID of 8 for PROMIS Physical Function (PF) and Pain Interference (PI) scores in spine patients.[18] Understanding the MCID and factors that predict its achievement after surgery may help guide surgical decision-making, as well as surgeon and patient expectations.

The primary objective of this study was to examine the ability of preoperative PROMIS PF and PI scores to predict long-term postoperative achievement of MCID following lumbar spine surgery. Secondary objectives were to determine threshold scores useful for predicting which patients would achieve MCID after surgery and to evaluate the impact of other patient characteristics on MCID achievement after lumbar spine surgery.