Effectiveness not established: interventions for which insufficient or conflicting data or data of inadequate qual- ity currently exist, with no clear indication of harm.
• Unlikely to be effective: interventions for which lack of effectiveness has been demonstrated by negative evidence from a single rigorously conducted controlled trial, con- sistent negative evidence from well designed controlled trials using small samples, or guidelines developed from evidence and supported by expert opinion.
• Not recommended for practice: interventions for which lack of effectiveness or harm has been demonstrated by strong evidence from rigorously conducted studies, meta- analyses, or systematic reviews, or interventions where the costs, burden, or harm associated with the intervention exceed the anticipated benefit.