Correlation of mJOA, PROMIS physical function, and patient satisfaction in patients with cervical myelopathy: an analysis of the Michigan Spine Surgery Improvement Collaborative (MSSIC) database

Abstract

BACKGROUND CONTEXTPatient-reported outcomes (PROs) are increasingly utilized to evaluate the efficacy and value of spinal procedures. Among patients with cervical myelopathy, the modified Japanese Orthopaedic Association (mJOA) remains the standard instrument, with Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) and patient satisfaction also frequently assessed. These outcomes have not all been directly compared using a large spine registry at 2 years follow-up for cervical myelopathic patients undergoing surgery. PURPOSETo determine the correlation and association of PROMIS PF, mJOA, and patient satisfaction outcomes in patients undergoing surgery for cervical myelopathy. STUDY DESIGN/SETTINGRetrospective review of a multicenter spine registry database. PATIENT SAMPLEAdult patients with cervical myelopathy who underwent cervical spine surgery between 2/26/2018 and 4/17/2021. OUTCOME MEASURESPROMIS PF, mJOA, and North American Spine Society (NASS) patient satisfaction index. METHODSThe MSSIC database was accessed to gather pre- and postoperative outcome data on patients with cervical myelopathy. Spearman's correlation coefficients relating mJOA and PROMIS PF were quantified up to 2 years postoperatively. The correlations between patient satisfaction with mJOA and PROMIS were determined. Kappa statistics were used to evaluate for agreement between those reaching the minimum clinically important difference (MCID) for mJOA and PROMIS PF. Odds ratios were calculated to determine the association between patient satisfaction and those reaching MCID for mJOA and PROMIS PF. Support for MSSIC is provided by BCBSM and Blue Care Network as part of the BCBSM Value Partnerships program. RESULTSData from 2,023 patients were included. Moderate to strong correlations were found between mJOA and PROMIS PF at all time points (p<.001). These outcomes had fair agreement at all postoperative time points when comparing those who reached MCID. Satisfaction was strongly related to changes from baseline for both mJOA and PROMIS PF at all time points (p<.001). Odds ratios associating satisfaction with PROMIS PF MCID were higher at all time points compared with mJOA, although the differences were not significant. CONCLUSIONSPROMIS PF has a strong positive correlation with mJOA up to 2 years postoperatively in patients undergoing surgery for cervical myelopathy, with similar odds of achieving MCID with both instruments. Patient satisfaction is predicted similarly by these outcome measures by 2 years postoperatively. These results affirm the validity of PROMIS PF in the cervical myelopathic population. Given its generalizability and ease of use, PROMIS PF may be a more practical outcome measure for clinical use compared with mJOA.