Farm exposure in early childhood is associated with a lower risk of severe respiratory illnesses

In multivariable analyses controlling for age, sex, family size, household smoking, daycare, breast-feeding, and family history, early farm exposure remained a statistically significant protective factor for respiratory illness (OR, 0.44; 95% CI, 0.21-0.91) and allergic rhinitis based on medical record (OR, 0.33; 95% CI, 0.12-0.89; Fig 1, D). Methods Study design This cross-sectional cohort study comprised children between the ages of 5 and 17 years born within MESA between 1986 and 1999.E1 Informed consent was obtained from the parents of the children involved in the study and the study was reviewed and approved by the Marshfield Clinic Research Foundation Institutional Review Board. Asthma Interview Wheezing in past, wheezing in last 12 mo, wheezing after exercise in last 12 mo, parent has been told child has asthma, or child has taken medications for asthma Chart review Health care provider diagnosis of asthma, reactive airway disease, or wheezing and wheezing sign appears in record on more than 1 occasion separated by at least 60 d Allergic rhinitis Interview Runny nose ever without a cold, sneezing last 12 mo, or itchy red eyes Chart review Health care provider diagnosis of allergic or seasonal rhinitis for more than 12 mo or if child's parent reported hay fever on 2 separate occasions Chronic skin rash or eczema/atopic dermatitis Interview Rash ever for >6 mo, rash in last 12 mo, or has been told by health care provider that child has eczema or atopic dermatitis Chart review Health care provider diagnosis of eczema or atopic dermatitis on 2 or more separate occasions Severe respiratory illness Interview First 2 y of life ever had chest infection such as pneumonia, bronchiolitis, RSV infection, or bronchitis Chart review Pneumonia or emergency room visit for respiratory symptoms or hospitalized for serious respiratory infection (bronchiolitis, RSV, pneumonia/pneumonitis, croup) in the first 2 y of life Table E2 Demographic and early exposure characteristics Characteristic Early farm exposure(n = 268) No farm exposure(n = 247) P value Sex: male (%) 52.6 58.4 .46 White (%) 97.5 97.0 .94 Age (y) (mean, SD) 12.7 (3.7) 11.4 (3.5)