Cost-related nonadherence to medicines in people with multiple chronic conditions

Multimorbidity is common and frequently associated with medicine nonadherence. Although cost is a common reason for nonadherence, very little research has quantified cost-related nonadherence (CRNA) to medicines specifically in people with multimorbidity, the prevalence of CRNA for different conditions nor the impact of cost when prioritising treatment between conditions. To determine the extent of CRNA in people with multimorbidity and the patient characteristics associated with these behaviours. People reporting two or more chronic conditions responding to a rapid response module regarding prescription drug affordability fielded between January 1 and June 30 2016 in the Canadian Community Health Survey, a cross-sectional household survey. Ordinal logistic regression, adjusted for key sociodemographic, clinical and treatment related variables, of weighted population estimates of self-reported CRNA within one group of conditions, across multiple groups of conditions, or no CRNA. 10.2% of 8420 Canadians with multimorbidity reported CRNA. The majority (61%) reported CRNA within one group of conditions, especially respiratory (16%) and mental health disorders (17%). CRNA was more common in younger adults, people without employer or association drug insurance plans, poorer health status, more chronic conditions, and increased out-of-pocket prescription costs. Having no prescription insurance was associated with a higher probability of CRNA across multiple groups of conditions. People with multimorbidity primarily forego medicines because of cost within one group of conditions. However, those without drug insurance extended these behaviours to multiple condition groups. Further work is needed to determine how people prioritise the conditions and treatments that are foregone because of cost, and how to best incorporate this information into treatment plans.