However, there was no statistical difference between both treatment groups.

All assessments were made without knowledge of the treatment group.

These were then averaged to give overall mean rates for each treatment group.

Our subjects were the female offspring of the various treatment groups.

In each treatment group, 65 percent actually suffered a heart attack.

They were randomly assigned to one of three treatment groups.

In addition, the care offered to the special treatment group was not at all intensive.

The mean age for both treatment groups was about 50.

And no significant differences were found among the three treatment groups.

A method based on chance by which study participants are assigned to a treatment group.