IMPlementing IMProved Asthma self-management as RouTine (IMP2ART) in primary care: update to the study protocol for a cluster randomised controlled implementation trial

<title>Abstract</title> <p> Background This paper updates the protocol for the IMPlementing IMProved Asthma self-management as RouTine (IMP ² ART) trial previously published in 2023. The update describes the rationale for some changes to outcome definitions and provides a link to the statistical analysis plan and health economic analysis plan prepared prior to commencing analysis. Methods IMP ² ART is a parallel group, cluster-randomised controlled hybrid II implementation trial which aims to determine whether facilitated delivery of the IMP ² ART strategy increases the provision of asthma action plans and reduces unscheduled care in the context of routine UK primary care. 144 general practices were randomly assigned to either the IMP ² ART implementation strategy or control group. Following a facilitation workshop, implementation group practices received a range of resources to help them prioritise supported self-management; control group practices continued with usual asthma care. We report the rationale for changing the definition of the primary implementation outcome (asthma action plan provision), and also some secondary outcomes affected by national level changes in guidelines and incentivised standards of asthma care. The primary clinical outcome remains a record of unscheduled care (yes/no) in the second year after randomisation assessed from routine data. All changes were made in discussion with the Independent Trial Steering Committee, the sponsor and with the agreement of the funder. Trial registration: ISRCTN15448074. Registered on 2 December 2019. </p>