Occupational and leisure-time physical activity and prospective musculoskeletal pain-relief prescribed medication among blue-collar workers: 24-h device-measured physical activity and Danish registers

Musculoskeletal pain is the biggest contributor to burden of disease, causing excessive use of pain-relief medication. Non-pharmaceutical measures are called on for handling this burden. Guidelines recommend physical activity as an effective non-pharmaceutical measure. However, it is unknown if occupational physical activity has the same preventive effects on redeeming pain-relief medication as when performed during leisure-time ("The Physical Activity Paradox"). We aimed to investigate if the paradox contributes to the redemption of prescribed pain relief-medication. 24-h device-measured physical activity data [sitting, standing, light physical activity, moderate-to-vigorous physical activity (MVPA) and time in bed)] were collected from 824 workers using a thigh-worn accelerometer during work and leisure-time. Redeemed pain-relief prescribed medication was retrieved from the Danish National Prescription Registry during a 4-year follow-up. The prospective association between occupational and leisure-time physical activity and number of redeemed pain-relief prescribed medication was analyzed using a generalized linear model, adjusted for potential confounders. During follow-up, 53% of the workers redeemed a pain-relief medication. In leisure-time, 30 min more of MVPA per day were associated with 23% lower risk (RR = 0.77; 95% CI 0.64 - 0.94) of redeeming pain-relief medication. In contrast, occupational physical activity was not associated with the risk of redeeming pain-relief medication [RR = 1.04 (95% CI 0.89 - 1.20)]. Leisure-time MVPA was associated with lower risk of redeeming pain-relief medication, while no beneficial association was found for occupational MVPA. These findings support the paradox that the domain of physical activity is important for redeeming pain-relief medication. PERSPECTIVE: Leisure-time MVPA differs from occupational MVPA in its association with redeeming pain-relief medication. Increasing leisure-time MVPA may serve as an effective non-pharmacological strategy to reduce pain-relief medication redemption. These findings could potentially inform guidelines for managing musculoskeletal pain, highlighting the need to differentiate between occupational and leisure-time physical activity.