| 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 |
[9] Levonorgestrel IUD (HIV-infected): Todd CS, Jones HE, Langwenya N, Hoover DR, Chen PL, Petro G, Myer L. Safety and continued use of the levonorgestrel intrauterine system as compared with the copper intrauterine device among women living with HIV in South Africa: A randomized controlled trial. PLoS Med. 2020 May 22;17(5):e1003110. https://pubmed.ncbi.nlm.nih.gov/32442189/
Levonorgestrel IUD (HIV-infected): World Health Organization. Medical eligibility criteria for contraceptive use, Fifth edition (2015). https://www.who.int/publications/i/item/9789241549158