New life sciences research reported from University of Minnesota.(Clinical report)

According to a study from the United States, "The double-blind placebo-controlled design is commonly considered the gold standard in research methodology; however, subject expectation bias could subvert blinding. The primary aim of this study was to examine the impact of expectation bias."

"Specifically, we examined perceived treatment assignment on smoking cessation outcome rates among participants enrolled in a clinical trial of bupropion (150 mg SR, BID). Analyses were conducted on data collected during ''Kick It at Swope,'' a double-blind, placebo-controlled, randomized trial of 600 African-American smokers. Chi-square and multiple logistic regression analyses were used to examine the impact of perception of assignment on treatment effect and cotinine-verified smoking abstinence rates. Participants were predominantly middle-aged (mean 44.7, SD 11.2), African-American women (68.6%), who smoked 19 CPD (SD = 8.1). Most had completed at least a high school education or GED (51.6%), and 55% had a monthly family income

The researchers concluded: "Results support previous research that expectation bias associated with judgment of treatment assignment is a strong predictor of outcome and confirms this relationship in a smoking cessation trial using bupropion SR among African-American smokers."

Thomas and colleagues published their study in the Journal of General Internal Medicine (The impact of perceived treatment assignment on smoking cessation outcomes among ...