TABLE 3.

aRRs for ≥1 WCC Gap Over the First 2 Years of Life

	≥1 WCC Gap Over the First 2 y, aRR (95% CI)a
IOE	1.43 (1.20–1.71)*
Child race
White	Reference
African American	1.36 (1.18–1.56)*
Asian American	1.24 (1.04–1.48)*
Other	1.26 (1.09–1.46)*
Unknown	0.93 (0.69–1.26)
Ethnicity
Non-Hispanic	Reference
Hispanic	0.84 (0.72–0.98)*
Unknown	1.08 (0.84–1.39)
Insurance
Private	Reference
Medicaid	2.00 (1.58–2.53)*
Other or unknown	1.53 (0.90–2.63)
Low birth wt <2500 g	0.90 (0.81– <1.00)*
Complex chronic condition	0.82 (0.75–0.90)*
Child sex
Female	Reference
Male	0.97 (0.91–1.02)
Area-level povertyb	1.02 (1.01–1.02)*
Metropolitan residence	1.01 (0.81–1.27)

Generalized linear models with a log link and Poisson distribution.

^aAdjusted for all variables listed in the table, year of birth as a fixed effect, and clustering by practice by using robust variance estimation.

^bThe coefficient represents a change in the relative risk per 1% increase.

^*P < .05.