Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
First-born child’s estimated difference in probability (∆P, percentage points) of childhood atopic medication purchase at ages 0–15 by age difference with second-born sibling (years) with 95% confidence intervals. M1 adjusted for: child’s sex, birth year, and immigrant background. M2: M1 + region and urbanicity of residence. M3: M2 + household income and parental education. M4: M3 + mode of delivery and parental atopic medication purchases
