A new study in The Journal of the American Medical Association is adding fuel to the fire about Amgen's (Nasdaq: AMGN) and Johnson & Johnson's (NYSE: JNJ) anemia drugs, but I don't think investors should be that worried about the study.

Combining clinical trial data from multiple studies -- called a meta-analysis -- showed that Aranesp from Amgen and Procrit from Johnson & Johnson raised the risk of death in cancer patients by about 10%.

I'd liken this meta-analysis to the one recently performed on drug-eluting stents, which actually helped Johnson & Johnson, but hurt Boston Scientific (NYSE: BSX), rather than to Dr. Steven Nissen's meta-analysis that showed an increased risk of heart attacks in patients taking GlaxoSmithKline's (NYSE: GSK) Avandia. In the latter, the side effect was a relatively new finding, while this most recent analysis and the one for drug-eluting stents are basically regurgitating old data. In fact, the FDA already made the companies change their warning labels in response to data suggesting that aggressive use of the drugs could make cancer worse.

While the news is old, the companies aren't off the hook yet. An FDA advisory committee meeting on March 13 could result in recommendations to further restrict the use of the drugs in cancer patients.

In the worst-case scenario, the panel could recommend that the drugs not be used in cancer patients, but there's enough evidence that the drugs help reduce the need for transfusions to make a full curtailment doubtful.

It's more likely that the panel will recommend that doctors wait for patients to become more anemic before administering the drugs. That would take a bite out of sales since some patients wouldn't reach the new threshold, but won't do too much more damage than what's already been done.

Until the meeting next month, investors won't know how bad the damage (if any) will be, but a meta-analysis of old data isn't going to change the outcome of the meeting much.

Johnson & Johnson and Glaxo are picks of the Income Investor newsletter. If you'd like to see more ideas for stocks that pay dividends, grab a 30-day free trial of the newsletter and check out all of our past recommendations.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Meta-analysis has shown that the Fool's disclosure policy protects our readers.