Responsiveness of the PROMIS-10 Global compared to the Neck Disability Index in Patients Undergoing 1 and 2 Level Anterior Cervical Discectomy and Fusion (ACDF)

The reliance on patient reported outcomes (PROs) has substantially increased not only to augment current metrics of clinical success, but to capture the patient's perspective on the benefit of their treatment. As more PROs become utilized, the time and cost of longitudinal data collection and survey fatigue must be tempered with the benefit of the data collected. Therefore, this study sought to assess the responsiveness of the Neck Disability Index (NDI) compared to the PROMIS-10 Global Health Survey physical function T-score (PFT) and mental health T-score (MHT). A total of 264 patients that had undergone a single or two level anterior cervical discectomy and fusion (ACDF) between June 2021 and January 2024 were included. All patients completed their preoperative, 3-, and 12-month postoperative PRO assessments. A responsiveness analysis was performed and included: floor and ceiling effects, correlations among the PRO scores, and effect size indices (ESI) calculations. There were no floor or ceiling effects for the NDI and only 5.8% of the study cohort reached the floor or ceiling for the PROMIS-10 scores. The PROMIS T-scores showed weak to moderate correlations to the NDI, with the PFT having stronger correlations than the mental health T-score (MHT). The ESI demonstrated that the NDI was the most responsive tool with a maximum ESI of 0.98. The PROMIS-10 is a responsive and valid tool that provides insight into both the general physical function and mental health of a patient; however, it does not display the same discretionary ability to detect small changes in neck function that the NDI demonstrated. Therefore, the PROMIS-10 may be useful to provide preoperative assessment for patients undergoing ACDF but longitudinal evaluation to assess the outcomes of this surgery may be best left to the NDI.