asthma prevalence differ substantially depending on which data source is used: Weighted to
national levels, the prevalence estimates for asthma in the sample were 7.7% based on
medical records or 10.0% based on maternal reports. Restricting the definition of a case
to those for whom both mother and medical provider mention asthma yields a
prevalence of 4.1%; broadening the definition to include any child for whom either
the mother or medical provider reported the condition yields a prevalence of 13.6%.
findings are important because they help disentangle issues of study design and population
from those of reporting patterns by source of information. Most published studies can
report prevalence based on either mother’s reports (regardless of medical
records, which are unavailable in most health surveys, which corresponds to our
“mother’s reports” estimate of 10.0%), or on medical records (without knowing
mother’s reports, which corresponds to our “medical records” estimate of 7.7%).