Associations were stronger for infants 3 12 months of age than for infants 1 2 months of age, with odds ratios of 3.90 (95% CI: 1.87, 8.13) and 1.73 (95% CI: 0.80, 3.73), respectively, for 29°C compared with 20°C on the day of the event.
Inverse associations with NO2 and benzene were also stronger in infants that were not breast-fed and for infants whose mothers had low circulating vitamin D during pregnancy than in other infants, although stratum-specific estimates and interactions were not significant (Table 2).
In secondary analyses, associations of apnea and bradycardia with pollution were generally stronger in infants who were full term and of normal birth weight than in infants who were both premature and LBW.
Associations were generally stronger in infants who were full term and NBW compared with those observed among premature and LBW infants, although the CIs were wide and typically included a null association.
The effect was strongest for infants, whose per capita mortality risk increased fivefold (Fig. 2).
The adverse effect of the introduction of solids in the first 2 months of life on the postnatal risk of HIV infection was even stronger among infants of women with baseline CD4 count above 200 cells/ml: adjusted hazard ratio, 4.4 (95%CI, 1.6 12.3, p = 0.005).
This relationship appeared to be stronger in infants born to women who were obese before pregnancy, but not weight gain.
This association may be stronger in infants born to African Americans (β = −6.90, p = 0.15) than those to Whites (β = −2.54, p = 0.68), although neither reached statistical significance.
This trend was strongest among infants, children, and adolescents (OR 3.0 to 8.3), and weakest among adults and the elderly (OR 1.3 and 0.4).
This association was strongest among infants born to women with a pre-pregnancy BMI > 30, similar in African Americans and Caucasians.
