Musculoskeletal pain and ageing

Abstract

Musculoskeletal pain is a complex phenomenon involving biomechanics, inflammation and central pain processing pathways. The ageing process and ageing-related conditions can affect the course of musculoskeletal pain; conversely, the presence of pain can affect the ageing process, contributing to increased risks of adverse health outcomes. Despite the importance of managing pain in older adults, questions remain in terms of the best approach as the use of analgesics in this population is associated with increased risks of adverse events. This thesis contributes to the current knowledge of how age-related conditions such as multimorbidity and frailty interact with musculoskeletal pain and its management. The specific aims are: a) to determine whether frailty status is a risk factor for development of chronic or intrusive musculoskeletal pain; b) to determine whether pain increases the risk of developing the frailty phenotype; c) to describe the current management of vertebral compression fractures, a common and painful musculoskeletal condition typically seen in older adults; and d) to review and appraise the literature on the efficacy and safety of opioid analgesics for older adults with musculoskeletal pain.«br /» To address the first and the second aims, longitudinal data from the Concord Health and Ageing in Men Project (CHAMP), a prospective population based cohort study, were used.«strong» «/strong»A total of 1705 men aged 70 years or older, living in an urban area of New South Wales, Australia, were included in the CHAMP baseline study. Data on the presence of chronic pain (daily pain for at least 3 months), intrusive pain (pain causing moderate to severe interference with activities) and the criteria for the Cardiovascular Health Study frailty phenotype were collected in three waves, from January 2005 to October 2013. After adjusting for potential confounders, no association between frailty and future chronic or intrusive pain was observed. However, non-frail (robust and pre-frail) men who reported chronic pain were 1.60 (95% confidence interval (CI): 1.02 to 2.51, p=0.039) times more likely to develop frailty at follow-up, compared to those with no pain. For those reporting intrusive pain, the odds of developing future frailty were 1.64 (95%CI: 0.97-2.78, p=0.063). In summary, the presence of chronic pain increased the risk of developing the physical frailty phenotype in community-dwelling older men.«br /» To address the third aim, data from the Bettering the Evaluation And Care of Health (BEACH) program collected between April 2005 and March 2015 were used. Each year, a random national sample of approximately 1,000 GPs each recorded information on 100 consecutive patient encounters. All encounters at which vertebral compression fracture was managed were selected. Vertebral compression fractures were managed in 211 (0.022%; 95% CI: 0.018–0.025) of the 977,300 BEACH encounters recorded April 2005– March 2015. At encounters with patients aged 50 years or over, prescription of opioids analgesics (47.1 per 100 vertebral fractures; 95% CI: 38.4–55.7) was the most common management action. Prescriptions of paracetamol (8.2 per 100 vertebral fractures; 95% CI: 4-12.4) or non-steroidal anti-inflammatory drugs (4.1 per 100 vertebral fractures; 95% CI: 1.1-7.1) were less frequent. Non-pharmacological treatment was provided at a rate of 22.4 per 100 vertebral fractures (95% CI: 14.6-30.1). In summary, prescription of oral opioid analgesics remains the commonest general practice approach for vertebral compression fractures management, despite the lack of evidence to support this approach.«br /» The fourth aim concerns the efficacy and safety of using opioid analgesics in older adults with musculoskeletal pain. A systematic review with meta-analysis was performed including 23 randomized controlled trials with mean population age of 60 years or older that compared the efficacy and safety of opioid analgesics with placebo for musculoskeletal pain conditions. Opioid analgesics had a small effect on decreasing pain intensity (Standardised mean difference (SMD): -0.27; 95% CI: -0.33 to -0.20) and improving function (SMD: -0.27, 95%CI: -0.36 to -0.18), which was not associated with daily dose or treatment duration. The risk of adverse events was three times higher (OR: 2.94; 95% CI: 2.33 to 3.72) and treatment discontinuation four times higher (OR: 4.04; 95% CI: 3.10 to 5.25) in opioid treated patients. The systematic review concluded that, in older adults suffering from musculoskeletal pain, using opioid analgesics had only a small effect on pain and function at the cost of a higher risk of adverse events and treatment discontinuation. Therefore, for this specific population, the opioid-related risks may outweigh the benefits.«br /» From the results presented in the chapters of this thesis, important conclusions can be drawn: a) chronic musculoskeletal pain increases the risk of developing frailty in older adults and therefore, pain management should be part of a potential strategy to prevent frailty; b) despite being commonly prescribed for musculoskeletal pain in older adults, opioid analgesics alone are not likely to result in significant relief of chronic pain in these patients; c) instead of recommending opioid analgesics for persistent pain in older patients, guidelines should recommend comprehensive pain assessment, multimodal strategies and multidisciplinary approaches