T he rate of opioid prescription for pain treatment has been increasing rapidly in North America in the past 20 years.1,2 For example, between 2001 and 2010, the percentage of patients receiving an opioid prescription during an emergency department visit increased from 20.8% to 31%, a relative increase of 49%.1 Furthermore, the frequency of opioid prescription increases with age. Opioids are sometimes necessary to treat acute pain, but they can cause adverse effects, especially in the older population.4-6 It has been found that drugs that affect the central nervous system (e.g., drugs that cause sedation and dizziness) can increase the risk of falling.7 Falls are frequent among people aged 65 years and older (28%-35% fall each year) 8 and constitute a leading cause of injuries, hospital admissions and deaths among older people.
9Several studies have established an association between opioid use and risk of falls or fractures in the older population.10-17 In a nested case-control study, Moden and colleagues found that using psychotropic drugs increased the risk of falls in older people. Specifically, opioid use was more likely to induce a fall within the next week (odds ratio [OR] = 6.07 for men and 5.16 for women).13 In another study in a level-1 trauma centre with patients of all ages, falls were more prevalent among patients who had used opioids in the month preceding the trauma compared with patients who had not (32.8% v. 22.0%).10 Furthermore, Söderberg and colleagues found that taking opioids increases the likelihood of an imminent fall-related injury.12 For example, having a prescription of opioids filled 1 week before the fall is associated with an OR of 5.14 of falling compared with an OR of 1.23 when the prescription is filled within 4 weeks of the fall. However, other studies did not find a significant association between opioid use and falls, [18][19][20] and none examined this in severely injured older people who are at higher risk of death.The objectives of the study were to examine the association between recent opioid use and the risk, as well as the clinical outcomes, of fall-related injury in a large trauma population of older adults. We hypothesized that fall-related injuries will be more likely to occur with recent opioid use than injuries that occur from other mechanisms. Evidence for an association between opioid use and risk of falls or fractures in older adults is inconsistent. We examine the association between recent opioid use and the risk, as well as the clinical outcomes, of fall-related injuries in a large trauma population of older adults.