Headlines Contradict

One of the main reasons I started and continue to write this blog is the misleading nature of headlines regarding research studies.
Imagine the public's confusion over the dueling headlines of the last couple days.  Either there is more incidence of lung cancer and related illnesses among NYC 9/11 First Responders or there is no increase in cases.

It depends on how you read the study results, or more specifically, how you read the analysis that the researchers present, because we are not looking at the actual data to make our decision.

With only enough time to open the study published in the Lancet and glance through it quickly (looking for my friend Thomas Aldrich in the list of authors -he was there) I saw what the issue probably is. Ok - issues, there is more than one.  The second one is easier to explain - cancer takes many years to develop so whatever cases of cancer we see now are likely to only be the beginning.

The main factor for the confusion could be the use of Odds Ratios.  An OR of 1 means that there is no difference between two groups.  An OR of less than one indicates that one group is less likely to have a condition than another and a OR above 1 means they are more likely to.  For these studies, the question then becomes, are NYC 9/11 First Responders more likely than similar persons (matches or controls) who were not at the scene to have contracted cancer or another lung illness in the years that followed.

I believe the study(ies) break down the responders as Fire Fighters, Police and maybe even EMT.  In all instances the ORs are above 1 but not much so.  If it is 1.3 - we can say that the group was 1.3 x more likely to have been diagnosed with the condition or 30% more likely.  That sounds substantial but remember that with percent we have to look at the baseline.  I can't recall with precision, but it seems that the lifetime chance of lung cancer is well below 10 percent.  In other words, the risk might go from 9% to 11%.  

This would lead to the conclusion that both headlines are right - however, I firmly believe that the exposure to the chemicals in that smoke and debris will have long and lasting effects on the lungs and overall health of those workers and we are only beginning to grasp the extent of that.