Table 2.

Factor Structure

Item	Standardized Factor Loadings*			Thresholds†
	Irritability	Inflexibility	Difficulty With Routines	Between “Not at All” and “Somewhat”	Between “Somewhat” and “Very Much”
1. Does your child cry a lot?	.817			.653	2.132
2. Does your child have a hard time calming down?	.846			.992	2.629
3. Is your child fussy or irritable?	.823			.847	2.334
4. Is it hard to comfort your child?	.711			1.404	2.293
5. Does your child have a hard time being with new people?		.884		−.140	1.257
6. Does your child have a hard time in new places?		.885		.351	1.835
7. Does your child have a hard time with change?		.835		.535	2.064
8. Does your child mind being held by other people?		.742		−.328	1.162
9. Does your child have trouble staying asleep?			.745	.145	1.478
10. Is it hard to keep your child on a schedule or routine?			.670	.426	1.675
11. Is it hard to put your child to sleep?			.925	.225	1.363
12. Is it hard to get enough sleep because of your child?			.834	.182	1.349

Note: Model estimated in the combined primary care and replication samples; To account for the Baby Pediatric Symptom Checklist (BPSC) 3-option (non-continuous) response scale, we modeled responses to all BPSC items as categorical variables.

^*With categorical indicators, factor loadings can be interpreted as in standard factor models.

^†With categorical indicators, thresholds are estimated for each item rather than intercepts. The first threshold indicates the score on the latent variable at which the most likely observed response shifts from 0 (“not at all”) to 1 (“somewhat”), whereas the second threshold indicates the latent score at which the most likely observed response shifts from 1 (ie, “somewhat”) to 2 (ie, “very much”).