RESUMEN
Background: Various theories provide guidance on implementing, sustaining and evaluating innovations within healthcare. There has been less attention given, however, to personal theories drawn from practice and the expertise of managers and front-line staff is a largely untapped resource. In this paper, we share learning from experienced improvement organisations to provide a conceptual level explanation of the conditions necessary to facilitate and sustain improvement at scale. Methods: Staff (n=42) from three leading change organisations in the UK, spanning health, education and social care, took part in three consultation meetings with the aim of sharing knowledge about sustaining large-scale change. This included one government organisation, one National Health Service Board and one large charity organisation. Using a participatory grounded theory approach, the workshops resulted in a co-created theory. Results: The theory of Motivating Change describes the psychosocial-structural conditions for large-scale, sustained change from the perspectives of front-line staff. The theory posits that change is more likely to be sustained at scale if there is synergy between staff's perceived need and desire for improvement, and the extrinsic motivators for change. Witnessing effective change is motivating for staff and positive outcomes provide a convincing argument for the need to sustain improvement activity. As such, evidence of change becomes evidence for change. This is only possible when there is a flow of trust within organisations that capitalises on positive peer pressure and suppresses infectious negativity. When these conditions are in place, organisations can generate self-proliferating improvement. Conclusions: The theory of Motivating Change has been co-created with staff and offers a useful explanation and guide for others involved in change work that capitalises on front-line expertise.