Bias in reporting efficacy and toxicity in breast cancer trials

A recent paper did an analysis of breast cancer studies published over the last 16 years.  They evaluated 164 trials and looked at whether results re: the drug’s toxicity or overall survival rate was reported prominently in the abstract, within the article, or at all.  They looked at who funded the work, the impact factor of the journal the work was published in, and most interestingly, whether the trial found positive or negative results.

From the article:

Fifty-four trials (32.9% of the total sample) were reported as positive, based on a non-PE, despite not finding a statistically significant difference in the PE. These reports were biased and used spin in an attempt to conceal that bias. When assessing only those reports with a non-significant difference in the PE between the arms (N = 92), the incidence of this bias increased to 59.0%. Compared with studies with a statistically significant difference between arms in the PE, studies with a non-significant difference showed a statistically significant association with not reporting the PE in the concluding statement of the abstract (27% versus 7%, OR = 5.15, 95% CI = 1.86–14.26, P = 0.001.)

…

A total of 110 (67.1%) papers met our definition of biased reporting of toxicity. Distribution of bias according to the hierarchy scale is reported in Table 2. There was a statistically significant association between biased reporting of toxicity and observation of a statistically significant difference in the arms for the PE (OR = 2.00, 95% CI = 1.02–3.94, P = 0.044).

Interestingly, they found industry-funded trials to show no more bias on average than other trials.

([via](http://well.blogs.nytimes.com/2013/01/14/clinical-trials-flawed-by-biased-reporting/))