The psychometric performance of the EQ-HWB-9 for measuring health and wellbeing in a general population sample from Australia and New Zealand

Purpose The EuroQol Health and Wellbeing Short (EQ-HWB-9) is a new, generic 9-item instrument, suitable for evaluating interventions in health and social-care settings for patients and caregivers. The instrument now requires validation across general and caregiver populations. Informal caregiving can be time-intensive and impact caregiver’s physical and mental well-being. However, caregiver outcomes are often overlooked in healthcare decisions, which can lead to inefficient resource allocation. We aimed to examine the psychometric performance of the EQ-HWB-9 in a general population dataset, including caregivers of persons with disability/chronic illness.

Methods Using general population samples, stratified by age, gender, region, ancestry, and income for Australia and New Zealand, we investigated EQ-HWB-9 item distribution and known-group validity (t-tests; Cohen’s d for effect size, with sub-group analysis by country, gender and age) across sum-scores and UK pilot preference-weighted scores. Item scores were compared across caregiver groups. Convergent validity was assessed between the EQ-HWB-9 and the Kessler-6 using Spearman’s Rho.

Results The sample included 2542 participants, 2018 from Australia and 524 from New Zealand. Item distribution was similar to previous studies. Known-group validity results aligned to a priori hypotheses for caregiver, mental health, physical health and disability and sleep issues variables. Caregivers had significantly higher scores across each item than their counterparts. Convergent validity conformed to a priori expectations.

Conclusion The EQ-HWB-9 appears valid in this general population setting. This study helps to build the evidence for the use of the instrument across diverse settings. Australian- and New Zealand-specific value-sets would be a good future addition.