Neck Disability Index Estimates SF-6D Utility Scores
Regression model estimates Short Form-6D utility scores from Neck Disability Index
FRIDAY, March 18 (HealthDay News) -- In patients with cervical degenerative disorders, Short Form-6D (SF-6D) utilities can be estimated using a Neck Disability Index (NDI) regression model, according to a study published online March 15 in Spine.
Leah Y. Carreon, M.D., of the Norton Leatherman Spine Center in Louisville, Ky., and colleagues developed an algorithm to allow SF-6D utilities to be estimated using information from the NDI. Short Form-36, NDI, and neck and arm pain scores were evaluated in 2,080 patients undergoing cervical fusion for degenerative disorders before surgery, and at 12 and 24 months after surgery. The patients' SF-6D utilities were calculated, and their SF-6D scores were estimated from the NDI and neck and arm pain scores. The algorithm was then validated in a separate cohort of 396 patients.
The researchers found a significant correlation between the SF-6D and the NDI, and neck and arm pain scores, with correlation coefficients of 0.82, 0.62, and 0.50, respectively. A regression model, which estimated SF-6D from NDI, had an R² of 0.66. There was no statistically significant difference between the actual mean SF-6D score and the SF-6D score estimated using a regression model based on NDI alone in the validation group.
"This regression-based algorithm may be a useful tool to predict SF-6D scores in studies of cervical degenerative disease that have collected NDI but not utility scores," the authors write. "This data could then be used to develop economic models that assess cost burdens and effectiveness of treatments of cervical spine diseases."
One or more of the study authors disclosed financial ties to the pharmaceutical and medical device industries.