Misreporting of coverage and cost-related non-adherence to prescription drugs: an analysis using the Canadian Community Health Survey

Abstract

Background: Canada is the only developed country with universal healthcare but no universal prescription drug coverage. Prescription drug coverage in Canada is often described as a “patchwork” system; eligibility for coverage varies by province and influenced by circumstance. Subsets of the population are eligible for partial or full provincial coverage for their prescription medications through public and/or private coverage.

Methods: The extent and factors associated with misreporting of drug insurance and cost-related non-adherence (CRNA) to prescribed medicines were investigated in three study populations: Ontario seniors 65 and over, Quebec seniors 65 and over, and Quebec adults 25-64 using pooled data from the 2015/2016 Canadian Community Health Survey (CCHS). The rationale for these study cohorts was that the vast majority had partial or full coverage for prescription medications from a public and/or private source. The factors associated with CRNA to prescribed medicines were also explored in these three subgroups.

Results: There is a degree of misreporting of drug insurance among Ontario seniors (17%), Quebec seniors (18%) and Quebec adults (9%). Quebec adults who declared CRNA to prescribed drugs had twice the odds of misreporting prescription drug coverage (OR 2.1 95% CI 1.3-3.4). Lower-income earners among Ontario seniors (OR 1.8, 95% CI 1.3-2.6), Quebec seniors (OR 1.7 95% CI 1.2-2.6), and Quebec adults (OR 3.4, 95% CI 2.3-5.1) were more likely to misreport coverage. Quebec seniors were more likely to misreport if they had less than a secondary school education (OR 1.4, 95% CI 1.1-1.8). Ontario seniors who were immigrants were more likely to misreport coverage (OR 1.5, 95% CI 1.2-1.8), as were Quebec seniors who were immigrants (OR 2.2, 95% CI 1.4-3.5). Ontario seniors who had a flu shot in the past 12 months (OR 0.7, 95% CI 0.5-9.9) and Quebec adults who had visited a GP in the past 12 months (OR 0.6, 95% CI 0.45,0.77) were less likely to misreport coverage. CRNA to prescribed drugs was reported by Ontario seniors (3.3%), Quebec seniors (2.5%), and Quebec adults (5.3%). Low-income Ontario seniors (OR 2.9, 95% CI 1.5-5.7) and Quebec adults (2.5, 95% CI 1.6-3.8) were more likely to report CRNA to prescribed medicines. Quebec adults with chronic conditions (OR 1.7, 95% CI 1.2-2.4) and those in self-reported poor health (OR 2.4, 95% CI 1.3-4.4) were also more likely to report CRNA to prescribed drugs.

Conclusions: There appears to be a socio-economic gradient in misreporting and CRNA among Ontario seniors, Quebec seniors, and Quebec adults. Given most of these subgroups will have coverage, we hypothesize a degree of measurement error among responses. More specifically, respondents who report CRNA to prescribed medicines may reflect measurement error.