Asthmatic/wheezing phenotypes in preschool children: Influential factors, health care and urban-rural differences.
BACKGROUND
Different wheezing and asthmatic phenotypes turned out to indicate differences in etiology, risk factors and health care. We examined influential factors and urban-rural differences for different phenotypes.


METHODS
Parents of 4732 children filled out a questionnaire concerning children's health and environmental factors administered within the Health Monitoring Units (GME) in a cross-sectional study in Bavaria, Germany (2014/2015). To classify respiratory symptoms, five phenotype groups were built: episodic, unremitting and frequent wheeze, ISAAC (International Study of Asthma and Allergies in Children) - asthma and physician-diagnosed asthma (neither of the groups are mutually exclusive). For each phenotype, health care variables were presented and stratified for residence. Urban-rural differences were tested by Pearson's chi-squared tests. Multivariable logistic regression was performed to analyze associations between influential factors and belonging to a phenotype group, and to compare groups with regard to health care variables as outcome.


RESULTS
Risk factors for wheezing phenotypes were male gender (OR = 2.02, 95%-CI = [1.65-2.48]), having older siblings (OR = 1.24, 95%-CI = [1.02-1.51]), and preterm delivery (OR = 1.61, 95%-CI = [1.13-2.29]) (ORs for unremitting wheeze). 57% of children with ISAAC asthma and 74% with physician-diagnosed asthma had performed allergy tests. Medication intake among all groups was more frequent in rural areas, and physician's asthma diagnoses were more frequent in urban areas.


CONCLUSIONS
In accordance with previous research this study confirms that male gender, older siblings and preterm delivery are associated with several wheezing phenotypes. Overall, low numbers of allergy tests among children with physician's diagnoses highlight a discrepancy between common practice and current knowledge and guidelines. Residential differences in health care might encourage further research and interventions strategies.
['Kutzora|Susanne|S|', 'Weber|Alisa|A|', 'Heinze|Stefanie|S|', 'Hendrowarsito|Lana|L|', 'Nennstiel-Ratzel|Uta|U|', 'von Mutius|Erika|E|', 'Fuchs|Nina|N|', 'Herr|Caroline|C|', '|||']
D001249:Asthma D002675:Child, Preschool D004781:Environmental Exposure D005260:Female D005858:Germany D006801:Humans D008297:Male D010641:Phenotype D047928:Premature Birth D012135:Respiratory Sounds D012307:Risk Factors
Wheezing phenotypes Children Health care Urban-rural differences Asthma Allergy test