8c7a652a___NEL__5
[0] Quantity Number of studies Number of study participants [1] One large study with a diverse population or several good quality studies Large number of subjects studied Studies with negative results have sufficiently large sample size for adequate statistical power [2] Several studies by independent investigators Doubts about adequacy of sample size to avoid Type I and Type II error [3] Limited number of studies Low number of subjects studied and/or inadequate sample size within studies [4] Unsubstantiated by published research studies [5] 
Relevant studies have not been done
- NEL
5