Polypharmacy and Excessive Polypharmacy Among Persons Living with Chronic Pain: A Cross-Sectional Study on the Prevalence and Associated Factors

Abstract

Ghita Zahlan,1 Gwenaelle De Clifford-Faugère,1 Hermine Lore Nguena Nguefack,1 Line Guénette,2,3 M Gabrielle Pagé,4,5 Lucie Blais,6 Anaïs Lacasse1 1Département des sciences de la santé, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Quebec, Canada; 2Faculté de pharmacie, Université Laval, Quebec, Quebec, Canada; 3Centre de recherche, CHU de Québec - Université Laval, Quebec, Quebec, Canada; 4Centre de recherche, Centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada; 5Département d’anesthésiologie et de médecine de la douleur, Faculté de médecine, Université de Montréal, Montreal, Quebec, Canada; 6Faculté de pharmacie, Université de Montréal, Montreal, Quebec, CanadaCorrespondence: Anaïs Lacasse, Département des sciences de la santé, Université du Québec en Abitibi-Témiscamingue, 445, boul. de l’Université, Rouyn-Noranda, Qc, J9X 5E4, Canada, Tel +1 819 762-0971, 2722, Email [email protected]: Polypharmacy can be defined as the concomitant use of ≥ 5 medications and excessive polypharmacy, as the use of ≥ 10 medications. Objectives were to (1) assess the prevalence of polypharmacy and excessive polypharmacy among persons living with chronic pain, and (2) identify sociodemographic and clinical factors associated with excessive polypharmacy.Patients and Methods: This cross-sectional study used data from 1342 persons from the ChrOnic Pain trEatment (COPE) Cohort (Quebec, Canada). The self-reported number of medications currently used by participants (regardless of whether they were prescribed or taken over-the-counter, or were used for treating pain or other health issues) was categorized to assess polypharmacy and excessive polypharmacy.Results: Participants reported using an average of 6 medications (median: 5). The prevalence of polypharmacy was 71.4% (95% CI: 69.0– 73.8) and excessive polypharmacy was 25.9% (95% CI: 23.6– 28.3). No significant differences were found across gender identity groups. Multivariable logistic regression revealed that factors associated with greater chances of reporting excessive polypharmacy (vs < 10 medications) included being born in Canada, using prescribed pain medications, and reporting greater pain intensity (0– 10) or pain relief from currently used pain treatments (0– 100%). Factors associated with lower chances of excessive polypharmacy were using physical and psychological pain treatments, reporting better general health/physical functioning, considering pain to be terrible/feeling like it will never get better, and being employed.Conclusion: Polypharmacy is the rule rather than the exception among persons living with chronic pain. Close monitoring and evaluation of the different medications used are important for all persons, especially those with limited access to care.Keywords: chronic pain, polypharmacy, excessive polypharmacy, prevalence, associated factors, determinant