| 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 |
[13] Doxycyline (21 days: Bubo): de Vries HJ, Smelov V, Middelburg JG, Pleijster J, Speksnijder AG, Morré SA.
Delayed microbial cure of lymphogranuloma venereum proctitis with doxycycline
treatment. Clin Infect Dis. 2009 Mar 1;48(5):e53-6. https://www.ncbi.nlm.nih.gov/pubmed/19191633