Table 2.

Preterm birth in relation to maternal trait anger expression, lifetime stress, and childhood trauma, in separate models, among mother-newborn pairs enrolled in the PRISM pregnancy cohort (n=628).

	Model 1	Model 2	Model 3
	RR (95% CI)	RR (95% CI)	RR (95% CI)
STAXI-2 Anger-out	1.06 (1.02, 1.11)	1.07 (1.02, 1.12)	1.06 (1.01, 1.11)
STAXI-2 Anger-in	1.05 (1.01, 1.10)	1.06 (1.01, 1.11)	1.05 (1.00, 1.10)
LSC-R lifetime stress	1.02 (1.01, 1.03)	1.01 (1.01, 1.03)	1.02 (1.00, 1.03)
CTQ sexual abuse	0.95 (0.43, 2.10)	0.99 (0.44, 2.20)	0.89 (0.41, 1.96)
CTQ physical abuse	1.17 (0.74, 1.85)	1.13 (0.69, 1.85)	1.06 (0.63, 1.76)
CTQ emotional abuse	1.49 (0.99, 2.47)	1.54 (0.91, 2.60)	1.41 (0.81, 2.45)

Abbreviations: CTQ: Childhood Trauma Questionnaire; LSC-R: Life Stressor Checklist-Revised; STAXI-2: State-Trait Anger Expression Inventory-2

Model 1: unadjusted

Model 2: adjusted for maternal age, race/ethnicity, and education

Model 3: adjusted for Model 2 variables plus cigarette smoke exposure (active smoking or exposure to ≥ 1 hour per week during pregnancy), parity, relationship status, and pre-pregnancy body mass index