Correlation between the Oswestry Disability Index and the 4-item short forms for physical function and pain...

The Oswestry Disability Index (ODI) is one of the most commonly used patient-reported outcome instruments, but completion of this 10-question survey can be cumbersome. Tools from the Patient-Reported Outcomes Measurement Information System (PROMIS) are an alternative, and potentially more efficient, means of assessing physical, mental, and social outcomes in spine surgery. Authors of this retrospective study assessed whether scores on the 4-item surveys of function and pain from the PROMIS initiative correlate with those on the ODI in lumbar spine surgery.

Patients evaluated in the adult neurosurgery spine clinic at a single institution completed the ODI, PROMIS Short Form v2.0 Physical Function 4a (PROMIS PF), and PROMIS Short Form v1.0 Pain Interference 4a (PROMIS PI) at various time points in their care. Score data were retrospectively analyzed using linear regressions with calculation of the Pearson correlation coefficient.

Three hundred forty-three sets of surveys (ODI, PROMIS PF, and PROMIS PI) were obtained from patients across initial visits (n = 147), 3-month follow-ups (n = 107), 12-month follow-ups (n = 52), and 24-month follow-ups (n = 37). ODI scores strongly correlated with PROMIS PF t-scores at baseline (r = -0.72, p < 0.0001), 3 months (r = -0.79, p < 0.0001), 12 months (r = -0.85, p < 0.0001), and 24 months (r = -0.89, p < 0.0001). ODI scores also correlated strongly with PROMIS PI t-scores at baseline (r = 0.71, p < 0.0001), at 3 months (r = 0.82, p < 0.0001), at 12 months (r = 0.86, p < 0.0001), and at 24 months (r = 0.88, p < 0.0001). Changes in ODI scores moderately correlated with changes in PROMIS PF t-scores (r = -0.68, p = 0.0003) and changes in PROMIS PI t-scores (r = 0.57, p = 0.0047) at 3 months postoperatively.

A strong correlation was found between the ODI and the 4-item PROMIS PF/PI at isolated time points for patients undergoing lumbar spine surgery. Large cohort studies are needed to determine longitudinal accuracy and precision and to assess possible benefits of time savings and improved rates of survey completion.