Identifying Correlation Among Patient-Reported Outcome Measures: A Study of PROMIS-29, ODI, and VAS in Adult Spinal Deformity Patients.

ABSTRACT

BACKGROUND: Adult spinal deformity (ASD) is becoming increasingly common in aging populations. Patient-reported outcome measures (PROMs) are self-reported patient surveys administered pre- and postoperatively that provide insight into patient improvement. We aim to compare 3 of the most utilized PROMs PROMIS-29, Oswestry Disability Index (ODI), and Visual Analogue Scale (VAS), to investigate whether they provide unique and independent assessments of patient outcomes when assessed longitudinally. METHODS: We retrospectively reviewed a database of ASD at UT Southwestern Medical Center between 2016 and 2021. Adult patients (>18 years old) were included if they underwent long-segment (>4 levels) thoracolumbar fusion. PROMIS-29, ODI, and VAS scores were collected preoperatively and at 3-, 6-, 12-, 18-, 24-, 30-, and 36-month follow-ups. Scores were recorded ±1 month of the time points. Pearson correlation coefficients for each PROM were then calculated in a pairwise fashion. RESULTS: A total of 163 patients were included in our analysis. ODI and VAS showed significant covariance, with VAS Neck and VAS Back having Pearson coefficients of 0.95 and 0.94, respectively. ODI and PROMIS-29 also showed significant covariance, with Physical Function and ODI showing a Pearson coefficient of 0.95. PROMIS-29 and VAS demonstrated less correlation regarding Pain and Physical Function; however, they showed a significantly high Pearson coefficient when comparing VAS Back with PROMIS-29 Sleep and Pain Intensity (r = 0.97 and r = 0.96, respectively). CONCLUSIONS: All 3 PROMs demonstrated significant correlation over 36 months, indicating that simultaneous administration of each during follow-up is redundant. The measure that provided the least unique information was ODI, as both VAS and PROMIS-29 demonstrated similar progression and assessed additional metrics. PROMIS-29 provided the same information as VAS and ODI, with extra facets of patient-reported outcomes, indicating that it may be a more comprehensive measure of longitudinal patient improvement.