| Level I | Good quality evidence |
Systematic review of RCTs with consistent findings High quality individual RCT |
| Level II |
Limited quality patient orientated evidence |
Systematic review of lower quality studies or studies with inconsistent findings Low quality clinical trial Cohort studies Case-control studies |
| Level III | Other |
Consensus guidelines, extrapolations from bench research, usual practice, opinion, disease-oriented evidence (intermediate or physiologic outcomes only), or case series |
[53] Tool for brief intervention for substance use disorders: ASSIST https://apps.who.int/iris/bitstream/handle/10665/44321/9789241599399_eng.pdf;jsessionid=BE4E60013BFEDCFFBDFF4B1DE1DE097A?sequence=1