because people are so different and the lives they lead are so different, how can we be sure that the double blind

Question: because people are so different and the lives they lead are so different, how can we be sure that the double blind trial system of testing medication/treatment is giving accurate results?
- Keywords:
  experiment,
  how science works
Asked by slj1997 to Charlotte, Dhvanil, Frank, Jim, Leila on 15 Mar 2013.
- Dhvanil Karia answered on 15 Mar 2013:
  
  We can never be sure but taking these factors into account in out results we can improve on out confidence levels for out results

Question: because people are so different and the lives they lead are so different, how can we be sure that the double blind trial system of testing medication/treatment is giving accurate results?