Monday, May 2, 2011


At the beginning of every change of the season some scientists publish a few papers in which they try to scare the pants off people. This time its “your calcium tablets may cause heart problems”.

I hate to say it again but it must be said: If the people who publish newspapers and magazines would read the actual reports in the medical journals they would not publish such hogwash.

This Spring’s publication is one that combines a number of studies which show no significant increase risk of heart attack or stroke. This is called “meta-analysis” which is another word for lumping a bunch of studies, some of which are poor, and seeing if anything comes out of it.

What happens when you do this is the number of people in the “meta-analysis” becomes large and this increases the likelihood that the average for all will become statistically significant. In this case the relative risk was barely significant (RR= 1.15 Confidence Interval; 1.03-1.27). Remember if the lower CI number is 1.0 the RR is not significant. So in this case, the RR is of marginal significance and would be considered by most to be of no consequence.

Remember if the relative risk is small the real or absolute risk (the only one that matters) is going to be exceedingly small.

This is very bad science and should not be published in any scientific journal. However, when it does get published the authors call the news media and indicate that the risk of heart and stroke problems “may be increased” by calcium tablets. Then the news media print headlines like “Calcium Tablets increase Risk of Heart Disease”.

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