The relationship between otitis media with effusion and contact with otherchildren in a British cohort studied from 8 months to 3 1/2 years

Objective: It is generally acknowledged that otitis media with effusion is more prevalent among children attending grouped day care. This study aimed to refine this by determining the relationships with the numbers of childre n at the place of day care, the age of the child and the number of siblings he/she had. Methods: ALSPAC (the Avon Longitudinal Study of Pregnancy and Childhood) is a population based longitudinal study starting early in pregn ancy and following the children throughout their lives. Nested within this study, a randomly selected group of 1590 children, the Children in Focus, w ere invited to attend a clinic for hands on examinations. Tympanometry was carried out at ages 8, 12, 18, 25, 31, 37 and 43 months of age. Bilateral o titis media with effusion (OME) was identified if both ears showed a flat t race. Multi-level modelling with logistic regression adjusted for a number of social and environmental influences. Results: Of the 1590 children invit ed to the 8-month clinic, 300 (19%) were excluded from the analysis because of failure to attend or because of missing data. The analyses were based o n 1290 children. The prevalence of bilateral OME decreased with age, from 2 4.6% at 8 months to 11.9% at 43 months. Children with older siblings and th ose attending day care with four or more other children were at an increase d risk of OME. The adjusted odds ratios (AOR) were 1.52 (95% confidence int erval [CI] = 1.23, 1.88) and 1.36 (95% CI = 1.02, 1.82), respectively. The risk associated with older siblings declined with age and by 3 years these children were no longer more likely to have OME than children with no older siblings. No such interaction with age was found for children in group day care and these children continued to be at an increased risk over the enti re age period of the study. There was no increased risk associated with day care when no other children attended (AOR = 1.18, 95% CI = 0.88, 1.58) or when one to three others were present (AOR = 1.10, 95% CI = 0.85, 1.42). Al though there was no relationship with the number of hours spent in day care , children who had started attending group care with four or more other chi ldren before 9 months of age did have an increased risk compared with child ren starting later AOR = 1.88, 95% CI = 1.12. 3.14. Conclusions: These resu lts provide evidence that early contact with other children increases the r isk of OME and that children attending day care with four or more other chi ldren remain at an increased risk of OME at least until 3 1/2 years. (C) 20 00 Elsevier Science Ireland Ltd. All rights reserved.