'Not all FDA approvals are created equally': Study reveals some medications get far less safety testing than others

The Yale analysis found the FDA allowed 37 percent of drugs onto the market after a single trial that was never replicated or confirmed

Just 34 percent of new drug approvals were backed by a study that lasted more than six months

The study concludes that patients' assumptions that doctors dole out trustworthy and effective drugs cannot be 'necessarily justified'

The Food and Drug Administration's OK is all that stands between drug companies and patients who need healing medications, but a new study reveals the agency's approval process doesn't scrutinize some drugs nearly as closely as others.



The Yale School of Medicine analysis published in the Journal of the American Medical Association on Tuesday found that how the FDA deems drugs 'safe and effective' varies widely drug to drug and suggests patients who think their doctors are doling out only safe and effective therapies should think again.



'Not all FDA approvals are created equally,' said Nicholas Downing, author of the study that bills itself as the first systematic look at the agency's standards for approval.

Was yours scrutinized? A study out of Yale reveals the widely varied standards the FDA uses to approve different new drugs

A startling number of some 188 therapies approved by the FDA between 2005 and 2012 were given the OK without having to cite long-term evidence of their effectiveness or safety.



Only 34% of the new drug approvals were backed by a study that lasted more than six months, according to the analysis of publicly available data.



And even if a drug company's successful study does last longer, it still doesn't mean the therapy is any more effective.

Some 37 percent were allowed on the market based on the results of a single trial that was never replicated or confirmed.



What's more, most of the drugs were never compared to existing treatments to see if they are better or worse, said the study.

Fewer than half were compared to treatments already on the market.



'Many other trials were small, short, and focused on lab values, or some other surrogate metric of effect, rather than clinical endpoints like death,' said Downing.



Although patients may think that doctors only dole out safe and effective medicines, a closer look at the FDA process raised doubts.

OK'd but is it okay? The FDA has a blemished safety record that includes drugs with major fatality rates. In 1996, 18million prescriptions were written for fenfluramine (left) as part of the weight-loss regimen phen-fen before it was revealed to have caused major heart-valve damage to a third of users. Vioxx (right) was wildly popular in the early 2000s until revelations of its deadly side effects on the heart became clear in the wake of the deaths of tens of thousands of American users



Cause for caution: Belviq (pictured) has become one of only two long term weight-loss drugs approved in the years since the phen-fen disaster

'Based on our study of the data, we can't be certain that this expectation is necessarily justified, given the quantity and quality of the variability we saw in the drug approval process,' Downing said.



These eyebrow-raising findings are nothing to ignore, but its authors admit there is merit to the FDA's reasons behind the varying levels of scrutiny.



'The agency applies the same statutory approval standards of safety and efficacy to all drugs, but uses regulatory flexibility in applying those standards,' spokeswoman Stephanie Yao said in a statement to the Washington Post.

In some cases, the FDA's 'regulatory flexibility' can pave the way for faster approval of 'potentially effective therapies for life-threatening diseases, such as certain cancers, or those diseases for which there is no existing effective treatment,' said the study.



To insist that all drugs meet the same standard could result in higher costs and longer wait times.



Still, researchers said the public and the regulatory community should be aware of the vastly differing standards for market approval.



'Based on our analysis, some drugs are approved on the basis of large, high-quality clinical trials, while others are approved based on results of smaller trials,' said senior author Joseph Ross, assistant professor of internal medicine at Yale School of Medicine.



'There was a lack of uniformity in the level of evidence the FDA used.'



The FDA does not require data on comparative effectiveness as part of its approval process, the JAMA study noted.

