Table 3.

Association between severe psychological distress (SPD) and increased caregiver burden: Results of logistic estimates

Variable	Adjusted odds ratio (95% confidence interval)
Burden
Increased caregiver burden (ref: Not increased caregiver burden)	1.90 (1.37–2.66)
Caregiver burden (J-ZBI-8)	1.05 (1.03–1.07)
Gender (ref: Female)
Male	0.80 (0.60–1.06)
Age (ref: 40–59 years)
15–39 years	2.31 (1.65–3.22)
60–79 years	0.24 (0.16–0.36)
Education (ref: High school educated or lower)
College educated or higher	1.03 (0.77–1.38)
Marital status (ref: Not married)
Married	0.94 (0.71–1.25)
Household income (ref: ≤ 2.9 million yen)
3.0–6.9 million yen	0.67 (0.47–0.96)
≥ 7.0 million yen	0.66 (0.44–0.97)
Unknown/undisclosed	0.52 (0.34–0.81)
Current job situation (ref: Not working)
Working	1.05 (0.78–1.43)
Disease treatment (ref: No)
Yes	1.33 (0.99–1.77)
Caregiving role (ref: Second caregiver)
Primary caregiver	0.93 (0.69–1.25)
The number of hours spent caring per day (ref: Short)
Middle	1.42 (1.05–1.93)
Long	1.95 (1.26–3.01)
The relationship to the care-receiver (ref: Children/children-in-law)
Spouse	1.60 (0.96–2.65)
Other relative	1.17 (0.82–1.68)
The care-receiver's care level (ref: Care need level 3–5)
Not qualified/unknown	1.10 (0.75–1.61)
Support level 1–2	1.31 (0.90–1.92)
Care need level 1–2	0.91 (0.65–1.28)

Ref: reference.

J-ZBI-8: the 8-item Japanese short version of the Zarit Caregiver Burden Interview.