Night pain in hip and knee osteoarthritis: a focus group study

To explore the experience of night pain in people with hip or knee osteoarthritis (OA).

Twenty-eight focus groups were conducted in 6 centers in 4 countries, with a total of 130 men and women with hip or knee OA. Two focus groups were excluded from the analysis, leaving 26 groups comprising 123 participants. Sampling was performed to ensure approximately equal representation of individuals with mild, moderate, and severe pain, hip OA, and knee OA. Format and methodology were standardized across centers, and participants described and discussed their experience of night pain. The focus groups were audio-recorded and transcribed. Data were analyzed by identifying emergent codes that were grouped and compared, resulting in the identification of key themes.

The majority of participants (81%) experienced night pain; the remaining 19%, who reported no night pain, were from the moderate or severe pain focus groups. Similar night pain experiences were expressed by the hip and knee OA participants. Night pain was also present regardless of the stage of OA, but severity increased as the disease progressed. Night pain was variable and intermittent. Three key themes were identified: prediction of night pain, sleep disturbance, and adaptations and treatment regimens.

Due to its variability and complexity, the assessment of night pain should take into account the importance of the patient narrative. Also, night pain may not be a distinct marker of disease severity, and this may have implications for its use as a priority indicator for total joint replacement.