Objectives: Toestimate the risks of community-associated Clostridium difficile infection (CA-CDI)amongthe populatioaged =65 years associated with antibiotic exposure and care home residence. Population and methods:We linked cases froma prospective study in Tayside, Scotland from1 November 2008 to 31 October 2009 to population datasets to conduct a cohort study and a nested, matched (1:10 by age and gender) case-control study. Results: There were 79039 eligible residents. CA-CDI incidencewas 20.3/10000 person years. In the cohort study, after adjustment,wefound a significantly increasing risk of CA-CDI with increasing age and comorbidity, prior hospital admission, care home residence [hazard ratio (HR) 1.96, 95% CI 1.14-3.34] and baseline antibiotic exposure (1.94, 1.35-2.77). In separate adjusted models, '4C' antibiotics (clindamycin, co-amoxiclav, cephalosporins, ciprofloxacin; 2.75, 1.78-4.26) and fluoroquinolones (3.33, 1.95-5.67) had higher associated risks. We matched 62 CA-CDI cases without recent (prior 3 months) hospital admission to 620 controls. In adjusted logistic regression models, exposure to any antibiotics increased the risk of CA-CDI (OR 6.04, 95% CI 3.19-11.43). Exposure to 4C antibiotics or fluoroquinolones had higher associated risks: adjusted OR 11.60 (95% CI 5.57-24.15) and 13.04 (4.91-34.64), respectively. Risk of CA-CDI increased with cumulative antibiotic exposure. Subgroup analysis of 42 cases with C. difficile cultured and 420 controls amplified all associations between antibiotic exposure and CA-CDI. Care home residence independently increased the risk of CA-CDI in all models. Conclusions: Our results have two important implications. First, they validate the classification of 4C antibiotics and fluoroquinolones in primary care as high risk for CA-CDI. Second, they demonstrate the importance of prior antibiotic exposure and place of residence for risk assessment by primary care prescribers. © The Author 2013. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.
Marwick, C. A., Yu, N., Lockhart, M. C., McGuigan, C. C., Wiuff, C., Davey, P. G., & Donnan, P. T. (2013). Community-associated Clostridium difficile infection among older people in Tayside, Scotland, is associated with antibiotic exposure and care home residence: cohort study with nested case-control. Journal of Antimicrobial Chemotherapy, 68(12), 2927-2933. https://doi.org/10.1093/jac/dkt257