Table 4.

State-level sentiment toward racial or ethnic minorities and individual-level birth outcomes.

State-level Twitter-derived variables (tertiles for race-related tweets that are negative)		Low birth weighta,b, incidence ratio (95% CI) or n		Preterm birtha,b, incidence ratio (95% CI) or n
Total sample
	Second tertile vs first tertile (lowest)		1.08 (1.03-1.13)		1.09 (1.04-1.13)
	Third tertile		1.08 (1.04-1.13)		1.08 (1.00-1.14)
	Number		9,985,402		9,988,030
Minorities
	Second tertile vs first tertile (lowest)		1.12 (1.04-1.19)		1.10 (1.05-1.15)
	Third tertile		1.13 (1.06-1.21)		1.10 (1.05-1.16)
	Number		4,920,300		4,921,577
White people
	Second tertile vs first tertile (lowest)		1.07 (1.02-1.12)		1.09 (1.03-1.15)
	Third tertile		1.08 (1.03-1.14)		1.08 (1.00-1.17)
	Number		5,407,779		5,409,230

^aData sources for health outcomes were 2015, 2016, and 2017 natality files. Tweets were collected from June 2015 to December 2017.

^bAdjusted log binomial models were run for each outcome separately. Models were controlled for year and state-level factors including percent non-Hispanic black people, percent Hispanic people, southern state indicator, population density, and economic disadvantage (standardized factor score summarizing the following variables [%]: unemployed, some college education, high school diploma, children in poverty, single parent household, and median household income), as well as individual-level factors including maternal age, sex, race, ethnicity, foreign birth, education, marital status, smoking, body mass index, first birth status, and prenatal care. Twitter-derived characteristics were categorized into tertiles, with the lowest tertile serving as the reference group. Cluster-adjusted errors are reported.