BLISS index using WOMAC index detects between-group differences at low-intensity symptom states in osteoarthritis

OBJECTIVES: The ability of the Bellamy et al. Low-Intensity Symptom State-attainment (BLISS) Index to differentiate between treatment groups (hylan G-F 20 vs. appropriate care) at low and very low levels of state attainment in patients with knee osteoarthritis was explored using the stiffness, function, and total index (TI) components of the WOMAC. STUDY DESIGN AND SETTING: Six different BLISS measures were analyzed using five WOMAC score thresholds: