Background Rigorous guideline development requires extensive time and resources. Rapid review—a streamlined approach to synthesising evidence—offers an attractive alternative to systematic review for informing decision-making on complex interventions in a timely manner. Complex interventions are those that contain extensive number of interacting components.

Context A rapid evidence assessment service of a large US-based health care organisation developed guidance through rapid review on transitional residential recovery services (TRSS) for substance abusers.

Description of Best Practice Complex interventions present unique challenges for evaluation by rapid review. Significant scoping and upfront communication with end users was undertaken to understand the target populations, intervention-related components, outcomes, timing and settings associated with TRSS. Thorough refinement of Ovid search algorithms using date-based limits was needed to generate a feasible and appropriate literature database. Issues relating to complex interventions—such as limited generalisability, lack of effect may be driven by poor implementation rather than ineffectiveness of intervention, variability in outcomes, etc.—were communicated to end users in conjunction with findings. Changes to existing programmes were enacted based on findings and will be discussed.

Lessons for Guideline Developers, Adaptors, Implementers, and/or Users Studies of complex interventions are notoriously difficult to evaluate and summarise through traditional evidence assessment methods. Rapid review offers an attractive option for providing evidence for timely decision-making; however, its application to complex interventions requires careful planning, execution and understanding.