Handling of confounding in diet and asthma, allergy studies poor

Handling of confounding in diet and asthma, allergy studies poor
Studies investigating the effect of diet on the development of childhood asthma and allergies generally have substantial shortcomings with regard to how they handle confounding and effect modification, according to research published online June 19 in Allergy.

(HealthDay) -- Studies investigating the effect of diet on the development of childhood asthma and allergies generally have substantial shortcomings with regard to how they handle confounding and effect modification, according to research published online June 19 in Allergy.

To examine confounders and effect modifiers that are considered and the approaches used to justify their inclusion in studies of diet and childhood asthma and allergies, Ulugbek Nurmatov, M.D., Ph.D., of the University of Edinburgh in the United Kingdom, and colleagues conducted a review of 62 studies, including 20 cohort, 16 case-control, 25 cross-sectional studies, and one ecologic study.

The researchers found that, although all cohort, cross-sectional, and ecologic studies considered effect modification and made some adjustment for confounding, only 44 percent of case-control studies did so. In those studies that did make adjustments, 74 percent provided no justification for why certain variables were considered. If justification was provided, it was typically based on (10 studies), conceptual justification (seven studies), or some combination of the two (three studies).

"This systematic review-based analysis provides evidence that the issues of confounding and effect modification have, on the whole, been inadequately handled in observational investigating the role of diet in the development of and allergic disease," the authors write. "The selection of confounders and effect modifiers should be primarily based on conceptual justification and secondarily on empirical evidence."

More information: Abstract
Full Text (subscription or payment may be required)

add to favorites email to friend print save as pdf

Related Stories

Preventing allergies

Oct 06, 2009

Vaccination can lower children's risk of allergy. Cathleen Muche-Borowski and her coauthors present a clinical practice guideline for allergy prevention in the current issue of Deutsches Ärzteblatt International (Dtsch ...

Recommended for you

How Staph infections elude the immune system

Oct 27, 2014

A potentially lethal bacterium protects itself by causing immune tunnel vision, according to a study from scientists at The University of Chicago published in The Journal of Experimental Medicine. By tri ...

Research reveals how lymph nodes expand during disease

Oct 22, 2014

Cancer Research UK and UCL scientists have discovered that the same specialised immune cells that patrol the body and spot infections also trigger the expansion of immune organs called lymph nodes, according to a study published ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.