| 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 |
[20] Albendazole: Rigter IM, Schipper HG, Koopmans RP, van Kan HJ, Frijlink HW, Kager PA, Guchelaar HJ. Relative bioavailability of three newly developed albendazole formulations: a randomized crossover study with healthy volunteers. Antimicrob Agents Chemother. 2004 Mar;48(3):1051-4. http://www.ncbi.nlm.nih.gov/pubmed/14982808