Tier I – Best-evidence Behavioral Interventions have:

• Significant and positive intervention effects on relevant outcomes
• No significant and negative intervention effects on relevant outcomes measured in the study
• Comparison group
• Unbiased assignment
• ≥ 3 months follow-up in both groups
• ≥ 70% retention in both groups
• Analyses adjusted for baseline differences in outcome measures (if non-RCT)
• At least 50 participants in the analytic sample in each group

(click here for more detailed Tier I criteria)

Tier II – Promising-evidence Behavioral Interventions have:

• Significant and positive intervention effects on relevant outcomes
• No significant and negative intervention effects on relevant outcomes measured in the study 
• Comparison group
• Unbiased or moderately biased assignment
• ≥ 1 month follow-up in both groups
• ≥ 60% retention in both groups
• Analyses adjusted for baseline differences in outcome measures (if non-RCT)
• At least 40 participants in the analytic sample in each group

(click here for more detailed Tier II criteria)

Tier III – Theory-based Interventions with positive outcome monitoring have:

• Behavioral change theory
• Logic model
• Formative research
• Positive process evaluation data demonstrating fidelity, availability, and acceptance
• Outcome monitoring showing positive and significant before and after changes in relevant outcomes

(click here for more detailed Tier III criteria)

Tier IV – Theory-based interventions with no outcome monitoring have:

• Behavioral change theory
• Logic model
• Formative research
• Positive process evaluation data demonstrating fidelity, availability, and acceptance

(click here for more detailed Tier IV criteria)