Background: Medication nonadherence is a frequent problem in chronic conditions. In chronic noncancer pain, medication is often used as an important cornerstone of the treatment. Studies on medication nonadherence in this population, however, are scarce.
Aim: The aim of this study was to determine the prevalence of medication underuse and overuse nonadherence in a large sample of chronic pain patients treated in a multidisciplinary pain center. Second, an extensive list of demographic, disease-related, treatment-related and health behavior-related factors was included to compare these factors between adherent, overusers, and underusers, respectively.
Methods: Self-report was used to measure medication adherence.
Results: Forty-eight percent of the patients were nonadherent, with 34% of them showing underuse and 14% overuse of the prescribed medication. Multivariable analyses showed a significant association between younger age and medication nonadherence (both underuse and overuse). Furthermore, underuse was significantly associated with self-medication. Overuse was associated with current smoking, opioid prescription, and more medication intake moments.
Conclusions: We can conclude that medication nonadherence, especially underuse of medication, occurs frequently among patients with chronic nonmalignant pain. Prospective research is needed to learn about the impact of medication overuse or underuse on clinical outcomes. Future research should examine underuse and overuse as different types of nonadherence as different factors might predict this behavior.