Randomization of Subjects

Subjects are assigned to study groups by a random mechanism not controlled by the patient or the investigator. Randomization increases the likelihood treatment groups are comparable with respect to distribution of measurable and measurable characteristics.

Randomization Schedule

Prior to study start, a randomization schedule is generated by a statistician. Ex. a 2 treatment trial with 1:1 randomization.

Treatment allocation schemes should:

• Be unpredictable
  • Neither the participant nor the investigator know in advance which treatment will be assigned (reduced observation bias)
• Promote balance
  • Groups must be alike in all important aspects and only differ in the intervention each group receives
• Be simple
  • Easy for investigator/staff to impelment

Generally, the randomization ratio should be equally allocated (1:1 randomization). Unequal randomization arises in some situations where we want more in one group than another due to costs or other factors.