Table 3.

Associations Between Baseline levels of Purpose in Life and Hemoglobin A1c at 4-Year Follow-up

Characteristics		Tertiles of purpose
		Low n=1,466	Medium n=1,238		High n=1,210
Model	Covariates	Coefficient	Coefficient	p-value	Coefficient	p-value
1	Baseline HbA1c	0.0 (reference)	−0.05 (−0.10 to −0.00)	.04	−0.08 (−0.13 to −0.03)	.002
2	Baseline HbA1c + sociodemographic factors1	0.0 (reference)	−0.04 (−0.09 to 0.00)	.06	−0.07 (−0.12 to −0.02)	.004
3	Model 2 + physical health and functioning factors2	0.0 (reference)	−0.04 (−0.08 to 0.01)	.13	−0.07 (−0.12 to −0.01)	.02
4	Model 2 + mental health factors3	0.0 (reference)	−0.05 (−0.09 to −0.00)	.042	−0.08 (−0.13 to −0.03)	.004
5	All covariates4	0.0 (reference)	−0.04 (−0.09 to 0.01)	.09	−0.07 (−0.13 to −0.02)	.01

HbA1c hemoglobin A1c.

¹Sociodemographic factors include age in years (continuous variable), gender, race (white/black/other), Hispanic ethnicity (Hispanic/non-Hispanic), years of formal education (<12, 12, >12), marital status (married / not married), and total household wealth (quartiles).

²Physical health and functioning factors include body mass index (continuous variable), physical activity (dichotomized to indicate ≥ twice weekly engagement in light, moderate, and/or vigorous activity), self-rated health (dichotomized to indicate fair/poor health), activities of daily living (dichotomized to indicate having difficulty in at least one ADL), and instrumental activities of daily living (dichotomized to indicate having difficulty in at least one IADL).

³Mental health factors include the eight-item Center for Epidemiological Studies Depression Scale (dichotomized to indicate ≥ 4 symptoms) and self-reported psychiatric diagnoses (yes/no).

⁴Full model details are shown in Appendix 1.