Nursing research often tests complex interventions. For example, the intervention may be delivered by different nurses, with varying levels of seniority and expertise and in diverse geographical locations. The efficacy (can it work) or effectiveness (does it work in the real world) of complex interventions is often evaluated within randomised controlled trials (RCTs). The most recent UK Medical Research Council (MRC) guidance1 on developing and evaluating complex interventions has shifted the emphasis from a focus of solely understanding whether or not an intervention achieves its intended outcomes to additional considerations such as why and how an intervention may, or may not, have an effect. The complex nature of the intervention, and the context within which it is delivered, means that there are multiple other processes that may influence whether or not the intervention is effective in real-world clinical practice.2 Process evaluations are recommended...

King et al conducted a systematic review of interventions aimed at reducing medication errors during inpatient rounds in children’s hospitals.1 Medication errors in hospitals may arise at many points in a complicated cascade of steps...