Changes in outcomes following exercise and education in individuals with single-site pain versus multi-site pain; an analysis of 31,276 patients with knee or hip osteoarthritis

OBJECTIVE: Multisite pain (MSP) in osteoarthritis defined as pain in ≥2 sites is associated with poorer health than single-site pain (SSP). We compared changes in health outcomes at 3- and 12 months in those with SSP versus MSP following an 8-week education and exercise programme (GLA:D®).

METHODS: Participants with knee/hip OA enrolled in GLA:D® (2014-2021) were categorised into four groups based on number of pain sites: 0-1 sites (SSP), 2 sites (MSP2), 3-4 sites (MSP3-4), ≥5 sites (MSP5+). Changes in pain, Quality of Life (QoL) and physical function were compared across groups at 3- and 12-months using Analysis of Covariance, Generalised Estimating Equations and responder analyses.

RESULTS: Approximately 90 % of 31,276 participants had ≥2 pain sites. At 12 months, pain severity reduced by a mean of -3.79 (95 % CI -4.90 to -2.68) in all MSP groups versus SSP. QoL improved by 1-2 points in MSP2 and MSP3-4 groups compared to SSP, with no difference in change in 40m walk or 30-second chair-stand. The proportion of pain responders was higher in all MSP groups compared to SSP at 3 (43-44 % vs 36 %) and 12 months (44-47 % vs 37 %). There was a greater proportion of responders in QoL in MSP2 versus SSP at 12 months (36 % vs 32 %); and in MSP3-4 versus MSP5+ at 3 months in physical function (56 % vs 52 %).

CONCLUSIONS: Whilst improvements in pain and QoL, but not physical function, were greater in those with MSP compared to SSP following an 8-week education and exercise programme, between-group differences were not clinically important.