A Nationwide Cross-Sectional Study of Self-Reported Adherence and Factors Associated with Analgesic Treatment in People with Chronic Pain

This study aims to shed light on the frequency and associated factors of self-reported adherence to analgesic treatment among chronic pain (CP) patients in the Spanish population. A nationwide cross-sectional study was performed of 1066 Spanish adults, of whom 251 suffered from CP and 168 had been prescribed analgesic treatment. Adherence was assessed using a self-reported direct questionnaire and related factors were collected. Descriptive and bivariate analyses were conducted. Among the 23.5% (95% CI: 21.0-26.2%) of the sample with CP, 66.9% (95% CI: 60.7-72.7%) were taking analgesic treatment prescribed by a doctor, and 81.0% (95% CI: 74.2-86.6%) said they took the treatment as the doctor indicated. However, 17.6% forgot to take the medication, 11% overused them when in great pain, 46.3% stopped the treatment when feeling better and 33.3% when feeling worse, and 7.3% stopped taking them for financial reasons. Higher intensity of pain, polymedication, administration route (injection/patches) and some patient-related factors were associated with self-perceived adherence to treatment. Most Spanish people with CP consider that they are adherent to their analgesic treatment. However, their behavior presents contradictions. It would be advisable for professionals to inform patients about appropriate behavior regarding their therapy recommendations, and to explore potential factors related to non-adherence. This could contribute to improving pain control.