Health State Utility Values Associated with Knee Osteoarthritis: A Vignette-Based Approach

Pain is the most common symptom of Osteoarthritis (OA) making OA one of the most frequent causes of mobility dependence and disability and resulting in a significant negative impact on health-related quality of life (HRQoL). The main objective of this study was to estimate health state utility values (HSUVs) associated with different levels of pain related to Knee OA (KOA).

Six different health state vignettes were developed using best practices and real-world data from the Osteoarthritis Initiative (OAI) database that included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) instrument. OAI data from individuals with KOA were categorized into 6 different pain profiles using patient responses to the WOMAC pain items (pain while: walking; climbing stairs; sleeping; resting and standing) each having response levels 0 (no)-4 (extreme). The six vignettes identified the most frequently observed response levels of the pain items. A time trade-off study was conducted in the UK among individuals with KOA.

Analysis dataset included 198 interviews. Participants' mean age was 51.6 years and 58.6% were females. Mean HSUVs ranged from 0.983 for the mildest health state, which was described as slight pain while climbing stairs and no pain on the other items, to 0.305 for the most severe health state which was described as extreme pain in all items.

This is the first known set of HSUVs estimated describing levels of pain most commonly reported by individuals with KOA. The results demonstrate considerable HRQoL burden in individuals with KOA.