Tuesday, December 18, 2007

What do these studies mean?

So many studies, so many findings – but can we tell if they mean anything to us?

The gold standard of clinical trials and studies is called the randomized double-blind, placebo-controlled study. All aspects, the randomizing, blinding and the placebo are important parts to ensure that people aren’t influenced by any aspect of the study.

Randomizing is important because it ensures the study subjects are not subconsciously divided into specific groups by the recruiters. By randomizing the patients (such as saying that every other patient goes into Group A or the first 10 go into A, second group into B, third into C and then the cycle starts again), they are distributed without influence from anyone working on the study.

Double blinding means that all direct participants in the study don’t know who is getting what. If the study is for drug A, it’s not good enough if the patient doesn’t now that he is taking A, the people who are giving it and those who are assessing the outcomes can’t know it. If they do, their interpretations and findings could be affected.

The placebo is also key, although it isn’t always as simple as a test of drug A or a placebo. You can have more than one group. For example, if drug B is already known to treat a disease but drug A is promising, there may be three groups of patients in the test: those who are given drug A, those who are given drug B and those who are getting the placebo. Or, there may be groups who get different dosages of drug A or placebo. So, you can see, there are many combinations that can happen.

The standard randomized, double-blind placebo studies have drawbacks though. It means that there are some sorts of studies that can’t be done because of ethical reasons. For example, if you know that a procedure can save a life, you can’t offer the placebo. You can’t have a psychological therapy that may prevent suicide, for example, and have half the group getting the therapy and the other half not.

These types of studies are also difficult to do for less common diseases and illnesses. The groups of available patients may not be large enough to have a good sample for such a study.

Arranging these studies is complicated and time consuming but, ultimately life saving if the drugs or procedures prove their worth.

News for Today:
Blood pressure dropped when pill taken at night: study
Severe psoriasis linked to higher death risk
Study examines factors associated with survival in advanced laryngeal cancer
Massage may help ease pain and anxiety after surgery
Suicide: holidays' darkest myth
Decongestant May Work at the Doses Now Recommended, FDA Panel Says


Dawn said...

You wouldn't believe how appropriate your post was. I'm doing a lot of reading on various trials etc and wondered exactly what that meant.

Thanks. And by the way. I read "Oscar" and thoroughly enjoyed his story. Well done.

Marijke Durning said...

Thank you so much Dawn - I'm always happy when my blog helps someone. And, thanks for the comment about Oscar's book. :-)