154. What PROMIS scores correlate with severe disability in cervical spine surgery

Abstract

BACKGROUND CONTEXT In recent years, the National Institutes of Health Patient Reported Outcomes Measurement Information System (PROMIS) has been shown to correlate well with legacy instruments such as the neck disability index (NDI) in patients with cervical pathology. However, because PROMIS is a global outcome measure, the clinical implications of a PROMIS score in patients with cervical spine surgery can be difficult to interpret. PURPOSE To better define the clinical implications of a PROMIS score in patients with cervical pathology indicated for surgery, we sought to determine how a disease-specific legacy instrument (NDI) correlated with PROMIS Pain Interference (PI) to define levels of substantial and minimal disability. We hypothesized that there would be a strong correlation between PROMIS PI and NDI, allowing for a definition of disability in cervical spine patients. STUDY DESIGN/SETTING This is an institutional review board-approved prospective cohort study. PATIENT SAMPLE Adults undergoing cervical spine surgery at a single institution were prospectively enrolled. Patients undergoing surgery for instability due to trauma were excluded. OUTCOME MEASURES Primary outcome measures included NDI and PROMIS PI scores. Methods Patients completed the NDI and PROMIS PI questionnaires preoperatively. Demographic data, presenting complaint, and procedural data were recorded. Correlation and regression analyses were performed. Results A total of 196 patients met inclusion criteria. The average age was 56.9 ± 12.9 years. The mean NDI score was 68.6 ± 38 and PROMIS PI was 60.9 ± 7.3. PROMIS PI was strongly correlated to NDI (r=0.76, p<0.001). Linear regression analysis revealed the following formula: PROMIS PI = 51.042 + 0.289*NDI (R2 = 0.57). Using an NDI score of 50 as a cut-off for severe disability, we found that PROMIS PI score of 65.5 or greater correlated with significant disability. Conclusions We performed a regression analysis allowing for conversion of PROMIS PI scores with NDI. In keeping with previous studies, our analysis showed that PROMIS PI was most strongly correlated to NDI. A PROMIS PI score greater than 66 was correlated to substantial disability (NDI=50). While a PROMIS PI score less than 59 was correlated to minimal relative impairment (NDI=28). These results provide an important reference as PROMIS reporting becomes more widespread in the literature. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. In recent years, the National Institutes of Health Patient Reported Outcomes Measurement Information System (PROMIS) has been shown to correlate well with legacy instruments such as the neck disability index (NDI) in patients with cervical pathology. However, because PROMIS is a global outcome measure, the clinical implications of a PROMIS score in patients with cervical spine surgery can be difficult to interpret. To better define the clinical implications of a PROMIS score in patients with cervical pathology indicated for surgery, we sought to determine how a disease-specific legacy instrument (NDI) correlated with PROMIS Pain Interference (PI) to define levels of substantial and minimal disability. We hypothesized that there would be a strong correlation between PROMIS PI and NDI, allowing for a definition of disability in cervical spine patients. This is an institutional review board-approved prospective cohort study. Adults undergoing cervical spine surgery at a single institution were prospectively enrolled. Patients undergoing surgery for instability due to trauma were excluded. Primary outcome measures included NDI and PROMIS PI scores. Patients completed the NDI and PROMIS PI questionnaires preoperatively. Demographic data, presenting complaint, and procedural data were recorded. Correlation and regression analyses were performed. A total of 196 patients met inclusion criteria. The average age was 56.9 ± 12.9 years. The mean NDI score was 68.6 ± 38 and PROMIS PI was 60.9 ± 7.3. PROMIS PI was strongly correlated to NDI (r=0.76, p<0.001). Linear regression analysis revealed the following formula: PROMIS PI = 51.042 + 0.289*NDI (R2 = 0.57). Using an NDI score of 50 as a cut-off for severe disability, we found that PROMIS PI score of 65.5 or greater correlated with significant disability. We performed a regression analysis allowing for conversion of PROMIS PI scores with NDI. In keeping with previous studies, our analysis showed that PROMIS PI was most strongly correlated to NDI. A PROMIS PI score greater than 66 was correlated to substantial disability (NDI=50). While a PROMIS PI score less than 59 was correlated to minimal relative impairment (NDI=28). These results provide an important reference as PROMIS reporting becomes more widespread in the literature.