Table 3 Characteristics of included randomized controlled trials (RCTs) in metformin (MET) for polycystic ovary syndrome (PCOS)
Features of included RCTs | Number of studies (n = 39) | % |
|---|---|---|
Year of publication | ||
1996 to 2001 | 7 | 17.9 |
2002 to 2007 | 12 | 30.8 |
2008 to February 2013 | 20 | 51.3 |
Revised CONSORT 2001 | ||
Before | 7 | 17.9 |
After | 32 | 82.1 |
Regions in which RCTs were conducted | ||
North America | 6 | 15.4 |
Europe | 16 | 41.0 |
Others | 17 | 43.6 |
Sources of trial funding | ||
Yes | 19 | 48.7 |
No | 20 | 51.3 |
Collaboration of different countries | ||
Yes | 8 | 20.5 |
No | 31 | 79.5 |
Choice of comparator interventions | ||
Placebo | 16 | 41.0 |
Sole intervention | 11 | 28.2 |
MET plus other therapies | 3 | 7.7 |
Some of above combinations | 9 | 23.1 |
Journals with most frequently published | ||
The Journal of Clinical Endocrinology & Metabolism | 9 | 23.1 |
Fertility and Sterility | 7 | 17.9 |
Human Reproduction | 6 | 15.4 |
The New England Journal of Medicine | 3 | 7.7 |
Eleven other journalsa | 14 | 35.9 |
Impact factors of included journalb | ||
0.00 to 2.99 | 10 | 25.6 |
3.00 to 5.99 | 24 | 61.5 |
6.00- | 4 | 10.3 |