Table 3.

Association of caregiver burden and positive aspects of caregiving with health indicators: unadjusted and adjusted ORs or coefficients and their 95% CI

	General health	Role physical	Role mental	Sleep problems	Pain intensity	Mental health	Vitality
Regression	Logistic	Logistic	Logistic	Mixed effects	Logistic	Tobit	Tobit
Effect size	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	Coefficient (95% CI)	Coefficient (95% CI)
Scale	0=good or very good 1=less than good	0=no limitations 1=some limitations	0=no limitations 1=some limitations	0 =<4 nights/week 1 =≥4 nights/week	0=no or light 1=moderate or more	0–100, higher values better mental health	0–100, higher values higher vitality
Objective caregiver burden
Hours of caregiving
Model 1	1.02 (0.90 to 1.14)	1.10 (0.96 to 1.25)	1.05 (0.94 to 1.18)	1.08 (0.94 to 1.25)	1.04 (0.93 to 1.16)	−0.52 (−1.36 to 0.33)	−0.08 (−1.06 to 0.89)
Model 2	0.97 (0.85 to 1.12)	1.08 (0.93 to 1.25)	1.04 (0.91 to 1.20)	1.08 (0.93 to 1.26)	1.01 (0.89 to 1.15)	−0.50 (−1.36 to 0.36)	−0.33 (−1.34 to 0.67)
Bootstrap 95% CI	0.78 to 1.21	0.88 to 1.31	0.81 to 1.34	0.92 to 1.27	0.82 to 1.24	−1.69 to 0.69	−1.50 to 0.89
Amount of ADL support
Model 1	1.08 (0.95 to 1.23)	1.09 (0.96 to 1.23)	1.09 (0.94 to 1.26)	1.04 (0.89 to 1.23)	1.08 (0.94 to 1.23)	−0.29 (−1.31 to 0.73)	0.23 (−0.95 to 1.41)
Model 2	1.06 (0.88 to 1.28)	1.08 (0.91 to 1.28)	1.06 (0.87 to 1.29)	1.05 (0.86 to 1.29)	1.04 (0.87 to 1.24)	−0.56 (−1.80 to 0.68)	−0.05 (−1.52 to 1.42)
Bootstrap 95% CI	0.83 to 1.36	0.87 to 1.33	0.81 to 1.34	0.86 to 1.30	0.83 to 1.30	−1.90 to 0.78	−1.81 to 1.74
Amount of IADL support
Model 1	1.05 (0.91 to 1.22)	1.15 (1.00 to 1.32)	1.07 (0.91 to 1.26)	1.11 (0.93 to 1.34)	1.01 (0.87 to 1.17)	−0.41 (−1.51 to 0.69)	0.47 (−0.82 to 1.75)
Model 2	1.02 (0.84 to 1.21)	1.11 (0.94 to 1.32)	1.05 (0.87 to 1.27)	1.06 (0.87 to 1.28)	0.95 (0.80 to 1.13)	−0.45 (−1.66 to 0.72)	0.26 (−1.13 to 1.66)
Bootstrap 95% CI	0.80 to 1.29	0.92 to 1.35	0.19 to 5.96	0.85 to 1.30	0.77 to 1.17	−1.75 to 0.81	−1.35 to 1.93
Subjective caregiver burden
Low burden (ZBI-S ≤12)	Reference (1.00)	Reference (1.00)	Reference (1.00)	Reference (1.00)	Reference (1.00)	Reference (0.00)	Reference (0.00)
High burden (ZBI-S >12)
Model 1	6.30 (2.30 to 17.21)***	4.87 (1.73 to 13.73)**	4.01 (1.40 to 11.46)**	6.59 (1.92 to 22.56)**	4.47 (1.64 to 12.11)**	−17.91 (−24.63 to −11.18)***	−19.12 (−27.18 to −11.05)***
Model 2	6.52 (1.97 to 21.52)**	4.18 (1.36 to 12.83)**	3.61 (1.11 to 11.70)*	5.34 (1.55 to 18.37)**	3.98 (1.37 to 11.54)*	−17.88 (−24.54 to −11.23)***	−20.27 (−28.40 to −12.14)***
Bootstrap 95% CI	1.30 to 32.65*	1.05 to 16.54*	0.39 to 33.73	1.49 to 19.18*	1.07 to 14.75*	−27.21 to −8.55***	−30.12 to −9.73***
Positive aspects of caregiving
No	Reference (1.00)	Reference (1.00)	Reference (1.00)	Reference (1.00)	Reference (1.00)	Reference (0.00)	Reference (0.00)
Yes
Model 1	1.02 (0.42 to 2.49)	1.73 (0.74 to 4.06)	1.92 (0.76 to 4.82)	1.29 (0.44 to 3.74)	0.86 (0.35 to 2.09)	5.19 (−0.85 to 11.23)	4.42 (−2.76 to 11.60)
Model 2	0.68 (0.24 to 2.24)	1.78 (0.64 to 4.93)	2.42 (0.76 to 7.73)	0.99 (0.30 to 3.21)	0.56 (0.19 to 1.71)	6.47 (0.18 to 12.75)*	3.68 (−4.10 to 11.45)
Bootstrap 95% CI	0.16 to 2.83	0.57 to 5.55	0.56 to 10.45	0.32 to 3.06	0.16 to 2.01	−0.72 to 13.66	−4.70 to 11.77

Model 1: unadjusted; Model 2: adjusted for age, sex, lesion characteristics of care receiver (lesion level, completeness, aetiology), time since caregiving, hours of paid work, financial hardship.

Missing values were imputed by multiple imputation. Bootstrap 95% CI are displayed for model 2.

Across the adjusted mixed models of sleep problem (models 2), ICC varied from 0.49 to 0.52, and McFadden’s pseudo R-squared measures from 0.18 to 0.23.

*p<0.05, **p<0.01, ***p<0.001.

p Values from equal FMI test.

ADL, activities of daily living; FMI, fraction-missing information; IADL, informal activities of daily living; ICC, intraclass correlation; ZBI-S, Zarit Burden Interview, short form.