| 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 |
[6] Progestin,oral (therapeutic class – restoring cyclicity): Singh S, Best C, Dunn S, Leyland N, Wolfman WL; Clinical Practice – Gynaecology Committee, Leyland N, Wolfman W, Allaire C, Awadalla A, Best C, Dunn S, Heywood M, Lemyre M, Marcoux V, Menard C, Potestio F, Rittenberg D, Singh S; Society of Obstetricians and Gynaecologists of Canada. Abnormal uterine bleeding in pre-menopausal women. J ObstetGynaecol Can. 2013 May;35(5):473-9. http://www.ncbi.nlm.nih.gov/pubmed/23756279
Progestin,oral (therapeutic class – restoring cyclicity):Sweet MG, Schmidt-Dalton TA, Weiss PM, Madsen KP. Evaluation and management of abnormal uterine bleeding in premenopausal women. Am Fam Physician. 2012 Jan 1;85(1):35-43. http://www.ncbi.nlm.nih.gov/pubmed/22230306