Evaluation of an interactive program for preventing adverse drug events in primary care: study protocol of the InPAct cluster randomised stepped wedge trial

Adverse drug events could often be prevented. One of their main causes is that patients rarely know how to detect them. Another cause is inadequate communication between patients and physicians. If patients were to be effectively trained in detecting and reporting adverse drug events, this should help to prevent their occurrence and subsequent complications. Our purpose is to present the protocol of the InPAct trial, which aims to evaluate an interactive program that encourages patients to report adverse drug events in primary care.

We will conduct a cluster randomised controlled stepped wedge trial, with eight clusters of 10 general practitioners each. The physicians will suggest to all of their antihypertensive-treated patients that they take part in this study. The InPAct program will be implemented in the clusters in random order along five successive three-month periods. Two new clusters will be trained in implementing the program at each step. The program features: an interactive patient booklet including informative paragraphs, several care plans and adverse drug event report forms; and standardised training of physicians in how to present the booklet to the patient. The primary outcome will be the reporting of adverse drug events by patients to their physician within three months. We assume that the number of patients reporting at least one adverse drug event will increase from 3% before program implementation to 7.5% afterward (coefficient of variation = 0.5, α = 0.05, β = 0.2), which means that 1,200 patients must be included. The effect of the intervention on the main outcome will be quantified and tested using a mixed logistic model to integrate cluster and time effects.

Our choice of a stepped wedge design is particularly appropriate for evaluating the implementation of a patient safety program within the constraints of general practice. We describe the InPAct intervention, which is an original program that is intended to improve communication between patients and physicians. Indeed, none of the previously published intervention studies has combined a patient education program and a patient reporting system for adverse drug events with the aim of improving patient safety in primary care.

This study is registered in ClinicalTrials.gov NCT01610817.