| 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 |
[14] Doxycyline (> 21 days: Bubo): Oud EV, de Vrieze NH, de Meij A, de Vries HJ. Pitfalls in the diagnosis and
management of inguinal lymphogranuloma venereum: important lessons from a case
series. Sex Transm Infect. 2014 Jun;90(4):279-82. https://www.ncbi.nlm.nih.gov/pubmed/24787368