TY - JOUR T1 - Chronic diseases and variations in rates of antimicrobial use in the community: a population-based analysis of linked administrative data in Quebec, Canada, 2002–2017 JF - CMAJ Open JO - CMAJ SP - E831 LP - E840 DO - 10.9778/cmajo.20210258 VL - 10 IS - 3 AU - Élise Fortin AU - Caroline Sirois AU - Caroline Quach AU - Sonia Jean AU - Marc Simard AU - Marc Dionne AU - Alejandra Irace-Cima AU - Nadine Magali-Ufitinema Y1 - 2022/09/01 UR - http://www.cmajopen.ca/content/10/3/E831.abstract N2 - Background: Chronic diseases may increase risk of infection and complications from infections; fear of these risks may lower clinicians’ tolerance threshold for the prescription of antimicrobials, thus increasing the risk of selecting resistant bacteria. We sought to describe rates of antimicrobial use in Quebec and measure the association between chronic diseases and utilization rates.Methods: Using the Quebec Integrated Chronic Disease Surveillance System, we analyzed data of people covered by the public drug insurance plan in 2002–2017. Based on delivered prescriptions, we described trends in antimicrobial use in the population, and per category of select chronic diseases (i.e., none, respiratory, cardiovascular, diabetes, mental disorder), according to age group (0–17 yr, 18–64 yr and ≥ 65 yr). We computed ratios of extended-to-narrow–spectrum antimicrobials in 2014–2017. We used robust Poisson regression to quantify the association between chronic diseases and rates of antimicrobial use among children and adults (≥ 18 yr).Results: Between 2002 and 2017, 4 231 724 prescriptions were received over 6 653 473 individual-years among children; 1 367 492 (20.6%) individual-years had at least 1 chronic disease. Among adults aged 18–64 years, 13 365 577 prescriptions were received over 24 935 592 individual-years; 9 533 493 (38.2%) individual-years had at least 1 chronic disease. Among adults 65 years or older, 11 689 365 prescriptions were received over 15 927 342 individual-years; 12 743 588 (80.0%) individual-years had least 1 chronic disease. Antimicrobial use decreased among children, remained stable among younger adults and increased among older adults. Trends were consistent across chronic disease categories in children and older adults. In 2014–2017, 19.9% of children, 39.1% of younger adults and 79.7% of older adults had at least 1 chronic disease. Claims for extended-spectrum antimicrobials were frequent in all age and chronic disease groups, relative to narrow-spectrum antimicrobials (ratios from 3.1:1 to 14.6:1). Antimicrobial use was higher among people with respiratory diseases (adults: relative rate [RR] 2.09, 95% confidence interval [CI] 2.07–2.10; children: RR 1.62, 95% CI 1.59–1.65), mental health diagnoses (adults: RR 1.48, 95% CI 1.46–1.49; children: RR 1.22, 95% 1.20–1.24), diabetes (adults: RR 1.40, 95% CI 1.28–1.41; children: RR 2.02, 95% CI 1.58–2.57) and cardiovascular diseases (adults: RR 1.31, 95% CI 1.30–1.32), compared with those with none of the studied chronic diseases.Interpretation: During the study period, large proportions of antimicrobial prescriptions were for people with chronic diseases, across the age spectrum. Interventions to reduce antimicrobial use should be tailored for these populations.See related research article by Fortin and colleagues at www.cmajopen.ca/lookup/doi/10.9778/cmajo.20210257 ER -