Perceived stress and depressive symptoms not neuropsychiatric symptoms predict caregiver burden in Alzheimer’s disease: a cross-sectional study

Table 3 Mediation Effect of Perceived Stress and Depression on the Relationship Between Neuropsychiatric Symptoms on Caregiver Burden Scores^a

	Outcome: ZBI-12		Product of coefficients		p-value	Bootstrapping Bias-corrected 95%CI
	Outcome: ZBI-12		Point estimate	SE	p-value	Lower limit	Upper limit
Model 1 (R² = 0.178)	Predictor: NPI	Mediator: -
Model 1 (R² = 0.178)	Total/direct effect		0.339	0.109	0.002	0.150	0.513
Model 2 (R² = 0.366)	Predictor: NPI	Mediator: PHQ-9
	Total effect		0.339	0.119	0.002	0.148	0.513
	Direct effect
	- NPI		0.206	0.101	0.040	0.041	0.366
	Indirect effect
	-via PHQ-9		0.133	0.049	0.006	0.082	0.293
Model 3 (R² = 0.393)	Predictor: NPI	Mediator: PSS
	Total effect		0.339	0.109	0.002	0.205	0.595
	Direct effect
	- NPI		0.179	0.110	0.104	−0.004	0.355
	Indirect effect
	-via PSS		0.160	0.058	0.006	0.086	0.351
Model 4 (R² = 0.459)	Predictor: NPI	Mediator: PSS/PHQ-9
	Total effect		0.340	0.109	0.002	0.151	0.513
	Direct effect
	-NPI		0.134	0.099	0.177	−0.030	0.293
	Indirect		0.206	0.061	0.001	0.119	0.318
	- via PSS		0.117	0.049	0.016	0.050	0.214
	- via PHQ-9		0.089	0.042	0.036	0.033	0.185

SE Standard Error, CI Confidence Interval, NPI Neuropsychiatric Inventory Questionnaires, PHQ-9 Patient Health Questionnaire-9, PSS Perceived Stress Scale, ZBI Zarit Burden Interview
^aCovariates were accounted for, i.e. Age, sex, years of education, level of clinical dementia rating, and level of activity of daily life

ISSN: 1471-2318