Validation of Veterans RAND 12-Item Physical Function Survey in Minimally Invasive Transforaminal Lumbar Interbody Fusion

Abstract

Background: Veterans RAND 12-item (VR-12) physical component score (PCS) has been validated in both veteran and US citizen populations; however, its use for spine surgery populations has not been evaluated. This study aims to correlate the VR-12 PCS survey with legacy patient-reported outcome measures (PROMs) in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).Methods: A prospective surgical database was retrospectively assessed for MIS TLIFs performed at 1 level from March 2015 to June 2019. Inclusion criteria were elective procedures for degenerative spinal pathology. Patients were excluded if they had surgery for metastatic, traumatic, or infectious etiologies or had incomplete preoperative 12-item Short Form (SF-12) PCS or Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF) survey. Additionally, patients with any incomplete VR-12 PCS surveys through 1 year were excluded. Demographics and perioperative characteristics were recorded. Mean postoperative PROM scores and score difference from preoperative baseline were calculated at each postoperative timepoint through 1 year. The relationship of VR-12-PCS with SF-12-PCS and PROMIS PF was evaluated with a Pearson's correlation coefficient and time-independent partial correlation.Results: A total of 59 patients underwent single-level MIS TLIFs. The cohort was 44.1% women with an average age of 53.8 years, and 52.5% were obese (body mass index ≥30 kg/m 2 ). The VR-12 PCS, SF-12 PCS, and PROMIS PF surveys had significant improvements from baseline to the 6 month through 1 year postoperative timepoints (P ≤ 0.001, all). All timepoints revealed strong VR-12-PCS correlations with SF-12-PCS and PROMIS PF (all P ≤ 0.001).Conclusion: VR-12 PCS, SF-12 PCS, and PROMIS PF scores all indicate statistically significant improvements in physical function for patients following MIS TLIF. VR-12 PCS was strongly correlated with the historically validated SF-12 PCS system as well as with the more recent PROMIS PF survey. Our observations give weight to utilizing the VR-12 PCS survey as a valid measure of physical function among patients undergoing MIS TLIF.