Ontario Healthcare Implementation Laboratory: A Learning Health System Approach That Leverages Data to Improve Quality in Primary Care: Stage 1

Background: Antibiotic overuse is the major driver of rising antimicrobial resistance rates. Unnecessary antibiotic use is associated with adverse medication side effects and rising rates of resistance. Mailing letters to high antibiotic prescribers in other countries have shown variables effects on reducing antibiotic prescribing.1-3

Objective: To evaluate the impact of a letter to the 25% of primary care physicians who prescribe the most antibiotics in Ontario on increasing enrollment for HQO primary care practice reports.

Secondary objectives: To test the impact of different formats of a notification letter on antibiotic prescribing. Our primary hypothesis is that notifying physicians that antibiotic use is being monitored will decrease use of antibiotics. The investigators further hypothesize that targeted change ideas on antibiotic initiation or duration will have varying impacts on these different prescribing behaviours highlighting the importance of targeted messaging.

Methods: The effect of letter mail outs to the top 25% prescribing primary care physicians will be evaluated using a randomized controlled trial (RCT) design. The investigators will allocate physicians to intervention versus control arms in a 3:3:1 ratio to maximize the number of physicians exposed to the intervention. The investigators are using the IQVIA Xponent database from March 2017 to February 2018 to identify the top 25% of primary care physician antibiotic prescribers in Ontario (family physicians or general practitioners) defined by total numbers of antibiotic prescriptions. They will be mailed a letter to indicate that they prescribe more antibiotics than 75% of Ontario primary care physicians, based on total numbers of antibiotic prescriptions per year. The letter will encourage them to sign up for HQO My Practice primary care reports which in the future may include antibiotic indicators.

The letter was designed using proven theoretical frameworks of behaviour change to improve antibiotic prescribing by physicians. Most physicians are aware of the global public health threat of antimicrobial resistance, however many underestimate its importance locally. Furthermore, unnecessary antibiotic prescribing is frequently attributed to external factors out of their control, such as patient expectations and patient adherence to medication.4 For this intervention the investigators focused on two behaviour change theories previously demonstrated to be associated with prescribing behaviour; Theory of Planned Behaviour (TBP) and Operant Learning Theory (OLT).5 The letter will provide some social normative comparison by indicating to these physicians that they prescribe more antibiotics than their peers (TPB). By providing change ideas and information on the consequences of unnecessary antibiotic use, the investigators are attempting to change the physicians' risk perception (TPB) and anticipated consequences (OLT) of prescribing antibiotics for acute respiratory tract infections. This letter represents a form of persuasive communication behaviour change technique (BCT). This form of BCT has shown to be effective in modifying OLT driven behaviours.6, 7