Table 1

Participation of an epidemiologist/biostatistician and the general characteristics of a controlled clinical trial

Yes % (n=178)No % (n=289)Totalp Value1-150
Type of design
Number of participating centres
 Not available1.10.40.6
Sample size
 Up to 10023.050.940.3<0.001
Approval by Institutional Review Board (IRB) and informed consent (IC)
Use of blindness
Treatment given to control group
 Other treatment51.146.748.40.528
 No treatment12.415.614.4
Death as main outcome
Source of funding
 Public agency37.629.432.60.002
 Private firms25.824.925.3
 None/not reported15.230.524.6
  • 1-150 Obtained by χ2 test. Totals may not total 100% because of rounding.