Short-form Zarit Caregiver Burden Interviews were valid in advanced conditions

Abstract 

Objectives

To assess six short-form versions of Zarit Burden Interview (ZBI-12, ZBI-8, ZBI-7, ZBI-6, ZBI-4, and ZBI-1) among three caregiving populations.

Study Design and Setting

Secondary analysis of carers' surveys in advanced cancer (n=105), dementia (n=131), and acquired brain injury (n=215). All completed demographic information and the ZBI-22 were used. Validity was assessed by Spearman correlations and internal consistency using Cronbach's alpha. Overall discrimination ability was evaluated using the area under the receiver operating characteristic curve (AUC).

Results

All short-form versions, except the ZBI-1 in advanced cancer (rho=0.63), displayed good correlations (rho=0.74–0.97) with the ZBI-22. Cronbach's alphas suggested high internal consistency (range: 0.69–0.89) even for the ZBI-4. Discriminative ability was good for all short forms (AUC range: 0.90–0.99); the best AUC was for ZBI-12 (0.99; 95% confidence interval [CI]: 0.98–0.99) and the second best for ZBI-7 (0.98; 95% CI: 0.96–0.98) and ZBI-6 (0.98; 95% CI: 0.97–0.99).

Conclusions

All six short-form ZBI have very good validity, internal consistency, and discriminative ability. ZBI-12 is endorsed as the best short-form version; ZBI-7 and ZBI-6 show almost equal properties and are suitable when a fewer-question version is needed. ZBI-4 and ZBI-1 are suitable for screening, but ZBI-1 may be less valid in cancer.

Keywords: Carer, Outcome, Palliative, Burden, Aging, Validity