News articles often fail to report on drug company funding and use brand names, two potential sources of bias, say researchers who reviewed coverage.

Most peer-reviewed medical journals require study authors to disclose their funding sources, but little is known about whether the information makes its way into news articles about medication studies.

In Wednesday's Journal of the American Medical Research, Dr. Danny McCormick of the department of medicine at Harvard Medical School in Boston and his colleagues reviewed 306 news articles about company-funded medication studies, and surveyed editors about the practice.

Of the 175 newspaper and 131 online articles published between 2004 and 2008, the funding source was not reported in 42 per cent of the articles, the researchers found.

When newspaper editors were surveyed, 88 per cent indicated that their publication often or always reported company funding in articles about medical research. Three per cent of editors indicated that their publication had a written policy stating that company funding should be reported.

The study's authors said they suspect that journalists often neglect to include the funding information because they don't know when a study has been sponsored by a company.

Medical journals could help by displaying the disclosures more prominently and including them in news releases summarizing the research, McCormick and his colleagues suggested.

In this case, the study was paid for by the department of medicine at Cambridge Hospital, and none of the authors reported any financial conflicts of interest.

Generic names preferable: reviewers

Referring to drugs by their brand names is another potential source of bias raised by the researchers.

"The unnecessary use of brand medications when a related generic could be used may account for as much as $9 billion in wasteful expenditures in the United States annually," the researchers added.

"The use of generic medication names by the news media is preferable so that physicians and patients learn to refer to medications by their generic names, a practice that is likely to reduce medication errors and may decrease unnecessary health care costs," the study concluded.

The researchers said they suspect that journalists may refer to medications by their brand names because they do not know whether the name is generic or brand.

Several newspaper editors also said they often refer to medications by their brand names because they believe readers are more likely to recognize the brands.

Of the 75 newspaper articles that editors reported as always using generic names, 76 per cent used brand names at least half the time, the researchers found.

No major differences were found between newspaper and online articles, and if an article appeared in both forms, the researchers alternated between which category it was assigned.

The reviewers said they focused on reporting of studies published in five top publications: New England Journal of Medicine, JAMA, Lancet, Annals of Internal Medicine and Archives of Internal Medicine.