Influences on the start, selection and duration of treatment with antibiotics in long-term care facilities

Abstract

Background: Understanding the extent to which current antibiotic prescribing behaviour is influenced by clinicians' historical patterns of practice will help target interventions to optimize antibiotic use in long-term care. Our objective was to evaluate whether clinicians' historical prescribing behaviours influence the start, prolongation and class selection for treatment with antibiotics in residents of long-term care facilities.

Methods: We conducted a retrospective cohort study of all physicians who prescribed to residents in long-term care facilities in Ontario between Jan. 1 and Dec. 31, 2014. We examined variability in antibiotic prescribing among physicians for 3 measures: start of treatment with antibiotics, use of prolonged durations exceeding 7 days and selection of fluoroquinolones. Funnel plots with control limits were used to determine the extent of variation and characterize physicians as extreme low, low, average, high and extreme high prescribers for each tendency. Multivariable logistic regression was used to assess whether a clinician's prescribing tendency in the previous year predicted current prescribing patterns, after accounting for residents' demographics, comorbidity, functional status and indwelling devices.

Results: Among 1695 long-term care physicians, who prescribed for 93 132 residents, there was wide variability in the start of antibiotic treatment (median 45% of patients, interquartile range [IQR] 32%-55%), use of prolonged treatment durations (median 30% of antibiotic prescriptions, IQR 19%-46%) and selection of fluoroquinolones (median 27% of antibiotic prescriptions, IQR 18%-37%). Prescribing tendencies for antibiotics by physicians in 2014 correlated strongly with tendencies in the previous year. After controlling for individual resident characteristics, prior prescribing tendency was a significant predictor of current practice.

Interpretation: Physicians prescribing antibiotics exhibited individual, measurable and historical tendencies toward start of antibiotic treatment, use of prolonged treatment duration and class selection. Prescriber audit and feedback may be a promising tool to optimize antibiotic use in long-term care facilities.

Figure 1:

Funnel plots of prescriber tendencies. Overall population averages are denoted by a black line in each plot. Each prescriber is represented by an individual filled circle. (A) Prescriber tendency to start treatment with antibiotics as a percentage of their unique patients in long-term care facilities in 2014. Prescribing tendencies are classified into extreme-low, low, average, high or extreme-high initiators, based on where they fall compared with the control limits at 2SD (dotted line) and 3SD (broken line). (B) Prescriber tendency to use treatment durations that exceeded 7 days as a percentage of their overall antibiotic prescriptions to patients in long-term care facilities. Prescribing tendencies are classified into extreme-low, low, average, high or extreme-high use of prolonged treatment duration, based on where they fall compared with the control limits at 2SD (dotted line) and 3SD (broken line). (C) Prescriber tendency to select fluoroquinolones as a percentage of their overall antibiotic prescriptions to patients in long-term care facilities. Prescribing tendencies are classified into extreme-low, low, average, high or extreme-high users of fluoroquinolones, based on where they fall compared with the control limits at 2SD (dotted line) and 3SD (broken line). SD = standard deviation.

Figure 2:

Correlations of prescriber tendencies in 2014 versus 2013. Each prescriber is represented by an individual black circle in the plots, with size proportional to clinical volume. (A) Prescriber tendency to start treatment with antibiotics. Prescribers shown as red circles were high or extreme-high starters in 2014. (B) Prescriber tendency to use prolonged durations of treatment with antibiotics. Prescribers shown as red circles were high or extreme-high users of prolonged durations in 2014. (C) Prescriber tendency to select fluoroquinolone antibiotics. Prescribers shown as red circles were high or extreme-high users of fluoroquinolones in 2014.