Sick Leave and Costs in Active Workers with Chronic Osteoarthritis Pain in Spain: Outcomes of the OPIOIDS Real World Study

Purpose: To estimate the number of sick leave days and productivity costs in active workers with osteoarthritis (OA) who initiated opioid treatment for moderate/severe chronic pain in clinical practice in Spain. Patients and Methods: This is a secondary analysis of the longitudinal, retrospective OPIOIDS study, using electronic medical records (EMR) of patients aged >= 18 years, who started an opioid treatment for moderate/severe chronic OA pain between 2010 and 2015 after treatment failure with >= 1 first-line drugs (acetaminophen, metamizole and/or nonsteroidal anti-inflammatory drugs [NSAIDs]). The number of days of sick leave and productivity costs were analyzed during a follow-up period of 36 months. Results: A total of 5089 patients with moderate/severe chronic OA pain, aged 56.8 years (standard deviation [SD]: 4.6) (56.6% were female), were analyzed: 73.3% of them started a treatment with weak opioids and 26.7% of them were treated with strong opioids. At 36 months, adherence was 21.0% (strong opioids: 15.4%; weak opioids: 23.0%; p<0.001), and 77% of patients had at least one sick leave related with chronic OA pain, with an average of 93 days off work in all working patients (120.5 days in patients with sick leaves). Besides, 16.9% of the study population had sick leave periods that lasted at least 6 months. Pain reduction was modest (-1.2 points; -4.0%, p<0.001). The cost of sick leave was (sic)2594 patient/year, and factors such as older age (beta=0.043), female sex (beta=0.036), comorbidities (beta=0.035) and strong opioid use (beta=0.031) were associated with higher productivity costs (p<0.05 in all associations). Conclusion: Active workers who started opioid treatment for moderate/severe chronic OA pain showed an increased frequency of sick leave and productivity cost, with a modest effect on pain relief. Older age, female sex, comorbidities, and strong opioids were associated with higher costs for society.