Health News Review

An updated analysis of the European Randomized Study of Screening for Prostate Cancer, published in the New England Journal of Medicine, is receiving a lot of news attention.

And the competing, conflicting headlines are as clear as mud.

In one corner, wearing the black-and-white trunks, and weighing in with  a predominantly positive message:

In the other corner, wearing the grey (area) trunks, and weighing in with more skeptical messages right up front:

To be clear – more clear than these headlines, at least – most of these stories got the message generally right in the body of the story.

But we all know that in today’s news-numbing-barrage, many people – myself included – may not make it past the headline depending on what the headline says.  The headlines matter.

And you can’t have it both ways: one saying “reduces death” and another saying “isn’t saving lives.”  Screening messages are confusing enough for the general public;  journalism shouldn’t make it even harder to decipher.

The final line of the NEJM article is this:  More information on the balance of benefits and adverse effects, as well as the cost-effectiveness, of prostate-cancer screening is needed before general recommendations can be made.  Maybe that should have received a little more attention.

Addendum:

For a more scholarly analysis of the research – not of the journalism, read Marya Zilberberg’s blog post.

(photo credit: Magharebia via flickr.com)

 

Comments

Gregory D. Pawelski posted on March 15, 2012 at 10:11 am

Thanks Gary! My head hurts enough trying to read these headlines, let alone the text.

Tim Bartik posted on March 15, 2012 at 4:11 pm

Gary:

I believe the journalistic coverage is somewhat confused because the researchers did not clarify what their study potentially CAN show and can’t show.

If you look at their study through the lens of statistics, it is clear that the European study, and all other prostate cancer screening studies, are vastly underpowered to detect effects on all-cause mortality. In brief, we have all cause mortality at around 20% in the control group, and prostate cancer mortality at around 0.5%. We are trying to detect a reduction in mortality of 0.1%. The European study has a large enough sample to detect a statistically significant decline in prostate cancer mortality from 0.5% to 0.4%. But it has nowhere near large enough a sample to have any hope of detecting a statistically significant change from 20% to 19.9%. It is hard to detect such a small RELATIVE change unless you have a huge sample, by my calculations a sample of over 5 million. For more details, see my comments to a post today at the blog prostate cancer infolink on the European study..

In any event, I think the journalism is confused because few journalists have sufficient statistics background to readily do a power analysis of empirical studies. The researchers did not help journalists by explaining this issue.

Tim Bartik

Tim Bartik posted on March 15, 2012 at 4:14 pm

Correction: I meant to say over 4 million is the required sample size, not over 5 million.

Tom Emerick posted on March 20, 2012 at 6:05 am

An excellent and timely write up. My vote is that PSA tests do not save lives. Your comments about small relative changes are spot on.

I told my doctor a few year ago to do no more PSA tests on me.