New model to explain the EQ-5D VAS in patients who have undergone spinal fusion.

BACKGROUND: In the health sector, the EQ-5D has been widely used to evaluate health-related quality of life, mainly due to its simplicity, robustness and plasticity in calculating years of life adjusted for quality. METHODS: However, its model has remained stable over time and knowledge of the influence of such biodemographical variables as age and gender has not been incorporated. This information, along with the well-known non-linear behavior of the VAS, which measures the self-concept of the 'General State of Health', forms the basis for a new model, which we present here from a sample of patients who were operated on for chronic low back pain. RESULTS: These are obtained using multiple regression analysis are consistent in terms of goodness-of-fit given that this new model is able to explain 91.3% of the self-concept of the 'general state of health'. CONCLUSIONS: Above leads to an improvement of 21.6% compared to the available models more robust and meets most of the restrictions for this type of statistical modeling.