Table 3.

Adjusted associations of allostatic load IRT and sum-scores with impact of depressive symptoms on daily life in the NHANES 2015–2016 study. Impact of depressive symptoms on daily life was measured by the question, “How difficult have these problems [PHQ9] made it for you to do your work, take care of things at home, or get along with people?” The response was coded as binary (not difficult at all or somewhat difficult vs. very or extremely difficult). We used logistic regression adjusted for age, sex, race/ethnicity and family income-to-poverty ratio. The models have different sample sizes, as IRT does not require complete data on all allostatic load biomarkers in order to calculate scores, unlike the sum-score approach.

Predictors	Odds Ratios	95% CI		p	Odds Ratios	95% CI	p
Intercept	0.08	0.03–0.21		<0.001	0.05	0.02–0.15	<0.001
AL IRT score	1.33	1.01–1.75		0.045
AL Sum score					1.07	0.96–1.19	0.204
Sex
Male	Reference
Female	1.28	0.83–1.99		0.267	1.16	0.72–1.86	0.544
Age (years)	1.02	1.00–1.04		0.041	1.02	1.00–1.04	0.047
Race/Ethnicity
Non-Hispanic White	Reference
Mexican American	0.16	0.06–0.37	<0.001		0.18	0.06–0.43	<0.001
Other Hispanic	0.68	0.35–1.26	0.24		0.84	0.41–1.60	0.606
Non-Hispanic Black	0.46	0.25–0.81	0.008		0.56	0.29–1.04	0.075
Non-Hispanic Asian	0.51	0.20–1.11	0.114		0.56	0.21–1.28	0.202
Other Race, including Multi-Racial	0.68	0.23–1.66	0.438		0.72	0.21–1.90	0.546
Family income-to-poverty ratio	0.58	0.48–0.68	<0.001		0.6	0.50–0.72	<0.001
Observations	2066				1849