Clinical trials: Around half of new treatments perform better than existing treatments

October 16, 2012, Wiley

On average, new treatments perform better in clinical trials only slightly more often than existing treatments, according to a new systematic review published in The Cochrane Library. The fact that experimental treatments are not more effective may seem disappointing, but the authors of the review say their findings satisfy an important ethical requirement for clinical trials.

Randomised trials compare the effects of one treatment to another. In a patients are randomly allocated to different treatment groups to ensure that like will be compared with like. When a new treatment is being tested, it is hoped or even expected that it will be better than the established treatment with which it is being compared. These expectations lead to an . If the researchers already know that one treatment is better, they would be knowingly allocating some people to an inferior treatment. If randomised trials are to be ethical, therefore, only half of new treatments should turn out to be better than existing ones.

Cochrane researchers looked at evidence from 743 publicly funded randomised trials involving 297,744 patients in total. The trials included new, experimental treatments for cancer and neurological disorders, as well as a range of other diseases. On average, only very slightly more than half of new treatments proved to be better than established treatments.

"When we compared the effects of new treatments to established ones, the pattern was almost symmetrical. This is good news, because it means researchers genuinely don't know whether new treatments are going to be any better," said lead researcher Benjamin Djulbegovic, who works at USF Health , and the H. Lee Moffitt Cancer Center & Research Institute, at the University of South Florida in Tampa, Florida, US. "So, overall, what we show is that we can expect the new treatments to perform better a little bit more often than established treatments, at least in publicly funded trials like the ones we considered."

The researchers found the same pattern in trials going back five decades. The results provide an answer to the question posed 15 years ago in the British Medical Journal by Iain Chalmers, a founder of the Cochrane Collaboration and one of the authors of the review. "In 1997, in a letter published in the BMJ, I asked 'What is the prior probability of a proposed new treatment being superior to established treatments?' I think this review currently provides the best answer to that question," said Chalmers.

Explore further: Drugs reduce bone cancer damage but clinical guidance remains non-specific

More information: Djulbegovic B, Kumar A, Glasziou PP, Perera R, Reljic T, Dent L, Raftery J, Johansen M, Di Tanna GL, Miladinovic B, Soares HP, Vist GE, Chalmers I. New treatments compared to established treatments in randomized trials. Cochrane Database of Systematic Reviews 2012, Issue 10. Art. No.:MR000024. DOI: 10.1002/14651858.MR000024.pub3

Related Stories

Drugs reduce bone cancer damage but clinical guidance remains non-specific

May 15, 2012
Bone cancer-related fractures and pain can be reduced by drug treatment, but no one drug is superior, according to a review published in The Cochrane Library. Researchers undertook a systematic review of the current evidence ...

Music reduces anxiety in cancer patients

August 10, 2011
(Medical Xpress) -- Cancer patients may benefit from sessions with trained music therapists or from listening to music. A new Cochrane systematic review shows using music can reduce anxiety in cancer patients, and may also ...

Exercise may improve quality of life during and after cancer

August 14, 2012
Exercise may improve quality of life for people with cancer, according to Cochrane researchers. In two separate Cochrane systematic reviews, the authors gathered together evidence showing that activities such as walking and ...

Recommended for you

Forces from fluid in the developing lung play an essential role in organ development

January 23, 2018
It is a marvel of nature: during gestation, multiple tissue types cooperate in building the elegantly functional structures of organs, from the brain's folds to the heart's multiple chambers. A recent study by Princeton researchers ...

More surprises about blood development—and a possible lead for making lymphocytes

January 22, 2018
Hematopoietic stem cells (HSCs) have long been regarded as the granddaddy of all blood cells. After we are born, these multipotent cells give rise to all our cell lineages: lymphoid, myeloid and erythroid cells. Hematologists ...

How metal scaffolds enhance the bone healing process

January 22, 2018
A new study shows how mechanically optimized constructs known as titanium-mesh scaffolds can optimize bone regeneration. The induction of bone regeneration is of importance when treating large bone defects. As demonstrated ...

Researchers illustrate how muscle growth inhibitor is activated, could aid in treating ALS

January 19, 2018
Researchers at the University of Cincinnati (UC) College of Medicine are part of an international team that has identified how the inactive or latent form of GDF8, a signaling protein also known as myostatin responsible for ...

Bioengineered soft microfibers improve T-cell production

January 18, 2018
T cells play a key role in the body's immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, ...

Weight flux alters molecular profile, study finds

January 17, 2018
The human body undergoes dramatic changes during even short periods of weight gain and loss, according to a study led by researchers at the Stanford University School of Medicine.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.