Effectiveness of participant recruitment strategies for critical care trials: A systematic review and narrative synthesis.

More effective recruitment strategies are required to enhance recruitment and the representativeness of the patient sample obtained in critical care trials, in order to expand the evidence base for treatments in this field. Greater focus is needed on assessing the performance of different recruitment strategies within different types of studies and critical care research environments. Future research should explore key stakeholders' experiences of, and attitudes towards, recruitment and establish the most important and feasible modifiable barriers to recruitment.