Outcome reporting bias in government-funded RCTs
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* An-Wen Chan
* Karmela Krleža-Jerić
* Isabelle Schmid
* Douglas G. Altman

*   © 2005 CMA Media Inc. or its licensors

In response to Pasquale Moja and associates, we would first like to clarify 2 points in their letter. First, it would be more accurate to state that a median of 26 outcomes was declared in both the protocols and the publications, rather than in the protocols alone. Also, with regard to the assertion that “research promoted through public funding is not free from bias,” we would clarify that it is not the research itself that is biased, but rather the reporting of the research.1

Moja and associates ask about the consistency of results across sources of funding. We would not expect significantly greater deficiencies among trials that were jointly funded by government and industry sources, as these studies were investigator-driven rather than fully controlled by the industry sponsor. Furthermore, formal subgroup analyses would be underpowered to detect any differences.

However, we do agree that stratifying the data by funding source would provide valuable preliminary insight into factors that might affect selective outcome reporting. Exploratory post hoc analyses for efficacy outcomes revealed consistent results across funding subgroups. The odds ratios for outcome reporting bias were 3.4 (95% confidence interval [CI] 1.3–9.3) for trials funded jointly by industry and CIHR (*n* = 11 trials) and 2.3 (95% CI 1.1–5.1) for trials funded by CIHR alone (*n* = 19 trials). The prevalence of major discrepancies in the specification of primary outcomes also did not differ significantly between jointly funded (7/20, 35%) or CIHR-funded (12/28, 43%) trials.

## Footnotes

*   *Competing interests:* None declared.

## Reference

1.  1. Chan AW, Krleža-Jerić K, Schmid I, Altman DG. Outcome reporting bias in randomized trials funded by the Canadian Institutes of Health Research. CMAJ 2004;171(7):735-40.
    
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