Investigation to identify a resource-efficient case-control methodology for determining antibiotics associated with Clostridium difficile infection.
BACKGROUND
Antimicrobial exposure remains an important risk factor for developing Clostridium difficile infection (CDI). Efficient method to identify antibiotics associated with CDI is important for formulating strategies to curtail their use. As a prelude to a more extensive Agency for Healthcare Research and Quality-funded project (Evaluation & Research on Antimicrobial Stewardship's Effect on Clostridium difficile), we undertook an exploratory evaluation to determine a resource-efficient method for identifying antibiotic targets for antimicrobial stewardship interventions.


METHODS
The study compared a series of 6 focused case-control studies. Cases consisted of patients with laboratory-confirmed CDI admitted from July-October 2009. Controls were selected from patients without CDI hospitalized during the same period. Five groups of controls were matched to cases (2:1 ratio) using group-specific matching criteria, including admission date, age, type of admission, length of stay (LOS) to discharge, and/or LOS to CDI diagnosis. The final control group was selected from patients who received antibiotics during hospitalization. Data, including demographics and antibiotic usage, were compared between case and control groups.


RESULTS
A total of 126 cases were matched to 6 groups of 252 controls. For control groups 1-5, the use of piperacillin and tazobactam, ceftriaxone or cefepime, ciprofloxacin or moxifloxacin, intravenous vancomycin, azithromycin, and antibiotics of last resort were significantly more frequent in case than control patients. For the final control group, the associations between ceftriaxone or cefepime, and ciprofloxacin or moxifloxacin use and CDI no longer persisted. This could in part be explained by differences in comorbidities between case and control patients even with stringent matching criteria.


CONCLUSION
Use of a simple matching strategy to conduct case-control studies is an efficient and feasible compromise strategy, especially in resource-limited settings, to identify high-risk antibiotics associated with CDI.
['Chung|Philip|P|', 'Currie|Brian|B|', 'Guo|Yi|Y|', 'Talansky|Moshe|M|', 'Brown|Shakara|S|', 'Ostrowsky|Belinda|B|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D000900:Anti-Bacterial Agents D016022:Case-Control Studies D016360:Clostridioides difficile D003428:Cross Infection D004761:Enterocolitis, Pseudomembranous D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D012189:Retrospective Studies D012306:Risk D055815:Young Adult
Clostridium difficile Antimicrobial stewardship Antibiotic targets Case control