Research funded by drug companies introduces bias

By Suneeta Kochhar London

Studies funded by the pharmaceutical industry are more likely to produce results favourable to the sponsoring company's product than research funded by other sources, according to a systematic review in the BMJ (2003;326:1167-70). This finding may be explained by publication bias and choosing inappropriate comparators to new drugs in clinical trials, rather than studies funded by industry being of a lower quality.

The pharmaceutical industry is increasingly funding more clinical trials. The industry spends more on medical research than the National Institute of Health in the United States. Despite pressure to show that a drug has a favourable outcome, the quality of the methods employed in studies funded by drug companies is comparable to research funded by other sources.

Joel Lexchin and colleagues found that research funded by drug companies takes longer to be published than research funded by other sources and that overall it is less likely to be published or presented. Furthermore, research funded by drug companies is usually presented in symposiums that lack peer review. The researchers comment that even though researchers cannot predict trial results far in advance, drug companies may selectively fund trials on drugs where a favourable outcome seems likely.

Drug companies have tried to prevent studies being published that are unfavourable to their products.