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Universal drug coverage and income‐related disparities in glycaemic control
Author(s) -
Branfield Day L.,
Austin P. C.,
Shah B. R.
Publication year - 2020
Publication title -
diabetic medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.474
H-Index - 145
eISSN - 1464-5491
pISSN - 0742-3071
DOI - 10.1111/dme.14051
Subject(s) - medicine , diabetes mellitus , medical prescription , population , demography , environmental health , endocrinology , sociology , pharmacology
Aims To examine whether income‐related disparities in glycaemic control decline after the age of 65 years, when publicly funded universal drug insurance is acquired in Ontario, Canada. Methods We conducted a population‐based cross‐sectional study using linked administrative healthcare databases. Adults with diabetes, aged 40–89 years, with available HbA 1c data were included ( N = 716 297). Income was based on median neighbourhood household income. Multiple linear regression was used to test for effect modification of age ≥65 years on the relationship between income and HbA 1c . Results There was a significant inverse association between income and HbA 1c level. After adjusting for baseline factors, the effect of income on HbA 1c level was significantly greater for individuals aged <65 years (mean difference HbA 1c for lowest vs highest income group +2.5 mmol/mol, 95% CI +2.3 to +2.7 [+0.23%, 95% CI 0.21 to 0.24]) than for those aged ≥65 years (+1.2 mmol/mol, 95% CI +1.0 to +1.3 [+0.11%, 95% CI 0.10 to 0.12]; P < 0.0001 for interaction). Conclusions Despite universal access to healthcare, people with diabetes with lower incomes had significantly worse glycaemic control compared with their counterparts on higher incomes. However, income gradients in glycaemic control were markedly reduced after the age of 65 years, possibly as a result of access to prescription drug coverage.