The funding announcement says that candidate interventions should be efficacious and/or widely used. What does that mean?

Efficacious programs and interventions are those for which data demonstrate a positive impact on the outcome(s) of interest. The efficacy of interventions should be clearly described and cited in the research application. Widely used interventions are those that are being broadly circulated and implemented in clinical practice, often despite a clear evidence base. Investigators claiming that an intervention is widely used should provide a clear and thoughtful rationale for that claim with accompanied by evidence of widespread use.