Table 3.

Multivariate models with interaction of HF self-care and depression on physical HRQOL

n= 196	β ± Standard Error	t	p value
PHQ9	1.64 ± 0.341	4.81	<0.001
SCMAIN	0.20 ± 0.039	5.30	<0.001
PHQ9 × SCMAIN	−0.01 ± 0.005	−2.14	0.034
n= 191
PHQ9	1.3 ± 0.237	5.49	<0.001
SCMGT	0.20 ± 0.033	6.16	<0.001
PHQ9 × SCMGT	−0.006 ± 0.004	−1.68	0.094

For SCMAIN model: ΔR² = 0.009, ΔF(1, 189) = 2.87, p = 0.007; For SCMGT model: ΔR² = 0.005, ΔF(1, 184) = 1.21, p = 0.11. The main effects of depression and self-care and the interaction of self-care maintenance but not self-care management and depression were significant at a p-value < 0.05. Additionally, a significant change in R² was observed with the inclusion of the interaction term (PHQ9 × SCMAIN) indicating self-care maintenance moderates the relationship between depressive symptoms and physical HRQOL. Each model was adjusted for age, Seattle HF Score, functional ability and co-morbidities. Albeit minimal, there was some marginal reduction in sample size due to missingness in model covariates.

Abbreviations: HF – heart failure; HRQOL - health-related quality of life; PHQ9 - 9-item Patient Health Questionnaire; SCMAIN - self-care maintenance; SCMGT - self-care management