Hi all
Can I ask for your collective thoughts on a paper published in Thorax please?
The study aims to use a cohort study to identify associations between childhood factors and reduced lung function and therefore risk of COPD. Interviews identidied a range of early life factors in a multisite cohort (n=13,359)of participants age 20-45 in 1991-1993, then repeated the measurements 9 years later in 7738 of the participants.
The two sets of measurements have been added together, giving n= 16,832 to make associations between childhood factors an dreduced lung function.
I am concerned that they are counting some people twice to make the association. Is this appropriate?
Interestingly there is no signficant association between these supposed childhood factors and decline in lung function over time (ie in those measured twice.)
THis does have implications - if childhood factors are more important that current smoking rates we may have to rethink stop smoking services.
I have tried to contact the author but no response so far.
I am happy to be told that this is appropriate and my understanding is wrong. I would just like to be able to explain the study to my Stop Smoking lead.
The article is:
THorax 2010 v65 p14-20
Early life origins of COPD
Svanes et al
http://thorax.bmj.com/content/65/1/14.full
thanks
Anne Gray
NHS Milton Keynes
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