| 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 |
[60] Methadone, oral: National Department of Health. National Policy guidelines on detoxification of psychoactive substances. http://www.health.gov.za/
Methadone, oral: Weich L, Nowbath H, Flegar S, Mahomedy Z, Ramjee H, Hitzeroth V, et al. South African guidelines for the management of opioid dependence. Updated 2013. Pretoria: South African Addiction Medicine Society; 2013. https://www.saams.co.za/Content/Documents/South_African_Guidelines_for_the_Management_of_Opioid_use_disorders_2015.pdf