"Since its emergence in early 2020, the COVID-19 crisis has affected every part of the world. Well beyond its health effects, the pandemic has wrought major changes in people's everyday lives as they confront restrictions imposed by physical distancing and consequences such as loss of work,...

The increasing imperative to find what works in health services has meant a rise in research trialing interventions deemed ‘complex’. While the strength of these interventions comes from taking a ‘whole of problem’ approach using multiple and inter-linking strategies, ways of examining...