RCT

RCT

1. Experimental

2. Controls exposure to the intervention & who receives it

3. Cause and effect identified

4. 2 TYPES

   • 1) Evaluate efficacy of an intervention to prevent disease
     • 2) Evaluate the efficacy of a drug/treatment used to manage/treat symptoms

5. GOOD STUDY DESIGN

   • 1) Random allocation- avoids bias, balances know/unknown confounders Control group similar to intervention
     • 2) Placebo use
       • 3) Blinding- Single, double, tripple
         • 4) Intenstion to treat analysis - all patients in each group analaysed together, introduces clinical reality (people not accepting or finising treatment)
           • 5) Ethics and stopping rules- informed consent

6. ADVANTAGES

   • 1) Draws conclusions on effectiveness of treatment
     • 2) Rigorous evaluation of a single variable in a defined group
       • 3) Prospective
         • 4) Blinding reduces bias
           • 5) Controls of known/unknown confounders
             • 6) Can be systematic review or meta analysis

7. DISADVANTAGES

   • 1) Can be time consuming
     • 2) Can be expensive
       • 3) Problems with participation/organisation
         • 4) Volunteer bias
           • 5) Loss of follow up
             • 6) Publication bias