Observer Bias High In Clinical Trials With Nonblinded Outcome

A new study of randomized clinical trials found significant observer bias toward a more beneficial treatment effect in nonblinded trials when the researcher knew the treatment being given to the participant. The study is published in CMAJ (Canadian Medical Association Journal). "Nonblinded assessors of subjective measurement scales outcomes in randomized clinical trials tended to generate substantially biased effect sizes," writes Dr. Asbjørn Hróbjartsson, The Nordic Cochrane Centre, Rigshospitalet Department, Copenhagen, Denmark, with coauthors... via Health News from Medical News Today Read More Here..