Importance Given that most common bacterial infections can be treated with antibiotic courses of 7 or fewer days, reducing standard antibiotic treatment durations may be an avenue to curtailing antibiotic overuse in long-term care.
Objectives To describe the variability in the duration of antibiotic treatment courses in long-term care across resident recipients and prescribing physicians and to determine whether this variability is influenced by prescriber preference.
Design and Setting Province-wide retrospective analysis of residents of Ontario, Canada, long-term care facilities in 2010.
Participants All adults aged 66 years or older who received an incident treatment course with a systemic antibiotic while residing in an Ontario long-term care facility.
Main Outcome Measure Antibiotic treatment duration was examined across residents and prescribing physicians. The proportion of a physician's treatment courses that exceeded 7 days was used to classify short-, average-, and long-duration prescribers.
Results Of 66 901 long-term care residents from 630 long-term care facilities, 50 061 (77.8%) received an incident antibiotic treatment course (with 51 540 antibiotic courses prescribed). The most commonly selected antibiotic treatment course was 7 days (in 21 136 courses [41.0%]), but 23 124 (44.9%) exceeded 7 days. Among the 699 physicians responsible for 20 or more antibiotic treatment courses, the median (interquartile range) proportion of treatment courses beyond 7 days was 43.5% (26.9%-62.9%) (range, 0%-97.1%). Twenty-one percent of prescribers had a higher-than-expected proportion of prescriptions beyond the 7-day threshold. Patient characteristics were similar across short-, average-, and long-duration prescribers. A mixed logistic model confirmed that prescribers were an important determinant of treatment duration (P < .001), with a relative odds of prolonged prescription of 3.84 for 75th vs 25th percentile prescribers.
Conclusions and Relevance Antibiotic treatment courses in long-term care facilities are often prescribed for long durations, and this appears to be influenced by prescriber preference more than patient characteristics. Future trials should evaluate antibiotic stewardship interventions targeting prescriber preferences to systematically shorten average treatment durations to reduce the complications, costs, and resistance associated with antibiotic overuse.