Objective: To describe trends in the occurrence of the common cold during the first 13 years of life among children who attended different childcare settings early in life.
Design: The Tucson Children's Respiratory Study involves 1246 children enrolled at birth and followed up prospectively since May 1980 through October 1984. Children with data regarding day care use during the first 3 years of life were included in this investigation (n = 991). Parents reported the occurrence of frequent (> or = 4) colds during the past year by questionnaire when each child was 2, 3, 6, 8, 11, and 13 years of age. Child care at home (no unrelated children), at small day care (1-5 unrelated children), or at large day care (> or = 6 unrelated children) was reported retrospectively by parental questionnaire when the children were approximately 6 years old.
Results: After adjusting for potential confounding variables, compared with children at home those in large day care had more frequent colds at year 2 (odds ratio [OR], 1.9, 95% confidence interval [CI], 1.0-3.4; P =.04), less frequent colds at years 6 (OR, 0.3, 95% CI, 0.1-0.9; P =.02) through 11 (OR, 0.4, 95% CI, 0.1-1.2; P =.09), and the same odds of frequent colds at year 13 (OR,1.0, 95% CI, 0.3-3.8; P =.95). In addition, compared with children in large day care for 1 year or less those attending large day care for more than 2 years had more frequent colds at year 2 (OR, 1.7, 95% CI, 1.0-3.0; P =.04), less frequent colds at years 6 (OR, 0.5, 95% CI, 0.2-1.1; P =.08), 8 (OR, 0.2, 95% CI, 0.1-1.0; P =.04), and 11 (OR, 0.3, 95% CI, 0.1-1.0; P =.05); and the same odds of frequent colds at year 13 (OR, 0.9, 95% CI, 0.3-2.9; P =.80).
Conclusions: Attendance at large day care was associated with more common colds during the preschool years. However, it was found to protect against the common cold during the early school years, presumably through acquired immunity. This protection waned by 13 years of age.