Table 3.

Summary of validity of EQ–5D, HUI3 in hearing impairments

Study	Instrument	Assessment	Methods	Summary of results
Barton et al. [24]	HUI3/EQ-5D/SF-6D	Convergence	Correlations between measures	Moderate to strong correlations were found between HUI3, EQ-5D and SF-6D.
Barton et al. [41]	HUI3	Known groups(severity) Convergence	HUI3 scores and severity groups defined by AHL level	HUI3 mean scores were different between moderate, severe, profound1, profound2 and implanted groups (significance not reported) CI (grouped by age at implantation and duration of use), AHL, gender were significant predictor of HUI3 (p < 0.01)
Bichey et al. [29]	HUI3	Known groups (severity)	HUI3 scores and PTA (presented by CI and HA group	HUI3 mean scores: 0.82 (CI) versus. 0.62 (HA) Consistent with PTA. No statistical test reported.
Damen et al. [43]	HUI3	Convergence	Spearman rho correlations between mean score of different measures at the follow-up	Correlation coefficients: 0.33 (HUI3 and AN test, p < 0.05) 0.39 (HUI3 and NVA test, p < 0.05) 0.48 (NCIQ and AN test, p < 0.05) 0.32 (NCIQ and NVA test, p < 0.05)
Lovett et al. [27]	HUI3	Known groups (severity)	HUI3 index scores and SSQ, VAS scores presented by unilateral and bilateral implantation groups	A significant difference (p < 0.05) in favour of bilateral (SSQ); No significant (p = 0.2) differences detected (HUI3 and VAS)
Palmer et al. [42]	HUI3	Known groups (severity)	HUI3 index scores presented by CI and non-CI implant groups at enrolment, 6 months and 12 months after CI implant.	Difference between CI and non-CI groups by HUI3: Not significant (baseline) and significant (p < 0.1) difference (0.76 for CI and 0.58 for non-CI) at both 6 and 12 months after intervention.
Smith-Olinde et al. [28]	HUI3	Known groups (severity)	HUI3 utility index presented by 4 groups defined by the degree of hearing loss	Both HUI3 and QWB scores declined with the degree of hearing loss where a greater extent for HUI3 than QWB. No statistical significance was presented
Gruters et al. [30]	EQ-5D (UK and Dutch tariff), HUI3	Known groups (age gender and severity) Convergence	Utility scores compared between age, gender (EQ-5D) and clinically distinctive groups (HUI3) Agreements between utility scores by Kendall’s Tau correlation and ICC	Significant differences detected: Age and gender (by EQ-5D); Clinical groups (by HUI3). Kendall’s Tau correlations: 0.36–0.41 (between EQ-5D with UK or Dutch tariff and HUI2, HUI3) ICC: 0.44–0.51 (between utility measures)
Sach and Barton [40]	EQ-5D	Known groups (through regressions)	Multiple linear regression was estimated between the child’s EQ-5D scores and CAP, as well as other variables)	Statistically significant coefficients (p < 0.05) for children with/without additional disabilities, gender, more severe deaf condition (measured by CAP); Non-statistical significant coefficients (p > 0.05) for children having mild deaf (in the top three levels of the CAP) and other socio-economic factors.

HUI3 Health Utility Index 3, AHL average of pure-tone air-conduction thresholds at the frequencies 0.5, 1, 2 and 4 kHz in the better hearing ear, PTA pure-tone average, CI cochlear implant, HA hearing aid, NCIQ the Nijmegen cochlear implant questionnaire, SSQ speech, spatial and qualities of hearing scale for parents, VAS Visual Analogue Scale, QWB Quality of well-being scale, EQ-5D euroqol 5 dimensions, ICC intraclass correlation, CAP categories of auditory perception