What is the relationship between physical activity and chronic pain in older adults? A systematic review and meta-analysis protocol

INTRODUCTION: Chronic pain is highly prevalent in older adults and can cause functional limitations, negatively affecting health and quality of life. Physical activity is a non-pharmacological approach used to prevent chronic pain as it promotes the release of endogenous opioids that block pain sensitivity. Therefore, we developed a systematic review protocol to analyse the relationship between physical activity and the occurrence and intensity of chronic pain in older adults. METHODS AND ANALYSES: The systematic review will search PubMed, Scopus and Embase databases. The inclusion criteria will be observational studies that had primary chronic pain as an outcome, including persistent and intermittent pain. The population will include older adults from the community, living in a long-stay institution, or in outpatient follow-up. There will be no restriction regarding the year of publication and articles published in Portuguese, English and Spanish will be analysed. Effect or impact measures will be quantified, including OR, HR, prevalence ratio, incidence ratio and relative risk with their 95% CIs. If the data allow, a meta-analysis will be performed. The results may help understand the impact of physical activity as a potential protection factor against the occurrence of pain later in life as well as promote strategic prevention plans and public policies that encourage this practice in older adults. ETHICS AND DISSEMINATION: Ethical approval is not required. The results will be disseminated via submission for publication to a peer-reviewed journal when complete. PROSPERO REGISTRATION NUMBER: CRD42021282898.