Table 3.

Exploratory factor analysis

Factors of ZBI	Item loading	Communalitya	Eigen-valueb	Per cent of variance	α-value
Factor 1: role intensity and resource strain			2.97	40.3%	0.90
1. Patient asking for too much help	0.384	0.21
2. Not enough time for caregiver	0.791	0.53
3. Worrying about fulfilling different responsibilities	0.597	0.52
8. Patient is dependent on caregiver	0.691	0.46
10. Health affected	0.503	0.44
12. Social life suffering	0.650	0.52
14. Expected to be the only carer	0.635	0.41
16. Feel unable to take care of the patient much longer	0.465	0.36
17. Sense of losing control over life	0.580	0.55
18. Wish somebody would take care over	0.502	0.42
22. Feel burdened	0.697	0.60
Factor 2: social restrictions and anger			1.24	7.0%	0.79
4. Embarrassed about patient’s behaviour	0.608	0.27
5. Feel angry	0.543	0.35
6. Negative effects on other relationships	0.496	0.26
9. Feel strained	0.623	0.44
13. Feeling uncomfortable having friends visit because of patient	0.600
Factor 3: self-criticism			1.13	5.9%	0.76
20. Feel should be doing more	0.818	0.17
21. Feel could do a better job	0.682	0.24

Only loadings ≥ .35 are shown

ZBI Zarit Burden Interview

^aCommunality = the total amount of variance that can be explained by a given principal component

^bEigenvalue = the proportion of each variable’s variance that can be explained by the factors