Absence of evidence is not evidence of absence.
Altman
D G
DG
Medical Statistics Laboratory, Imperial Cancer Research Fund, London.
Bland
J M
JM
D018849:Controlled Clinical Trials as Topic; D003627:Data Interpretation, Statistical; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D018401:Sample Size; D013223:Statistics as Topic