Incidence and risk factors of inappropriate antibiotic prescribing and related adverse health outcomes among Ontario long-term care residents and marginalized older community-dwelling adults with COVID-19 (I-CARE)

It is rare for patients with COVID-19 to have a bacterial infection at the same time as their viral infection, especially among non-hospitalized patients. Despite this, antibiotics are frequently prescribed unnecessarily in these patients. One particular group that is at high risk for inappropriate antibiotic prescribing in COVID-19 is older adults. Older adults, especially those in long term care homes (LTCH), are also highly susceptible to the toxicity of antibiotics including downstream complications such as Clostridioides difficile infection (CDI) and antimicrobial resistance (AMR). Marginalized older adults who do not live in LTCHs may also receive inappropriate antibiotic therapies and experience related adverse health outcomes during COVID-19 in Canada. To address these emerging concerns, we aim to study institutionalized and community-based older adults (66+ years of age) with confirmed COVID-19 to estimate (i) how frequently inappropriate antibiotics are prescribed and why, and (ii) how often complications including CDI and AMR occur, and what proportion of these complications are due to inappropriate antibiotic use. A particular focus with the community-based cohort will be whether neighbourhood-based aspects of marginalization (i.e., residential instability, material deprivation, dependency, and ethnic diversity) modify these impacts. We will rapidly perform two separate retrospective cohort studies, using existing linked clinical and administrative databases available in Ontario (ICES), to generate real-time evidence for accelerated sharing with government and public health stakeholders to improve our management of COVID-19. Our results will directly inform the equitable care of vulnerable populations and will evaluate the ongoing impact of COVID-19 on health systems and services by identifying risk factors for inappropriate medication prescribing and associated harms.