THE BLUES CLOUD THE VIEW: PROXY DEPRESSION IS ASSOCIATED WITH LOWER DYADIC AGREEMENT ON EQ-5D-5L
Author(s)
Soumana Nasser, PharmD1, Maja Kuharic, PhD2, A Simon Pickard, PhD3;
1Lebanese American University, Associate Professor, Pharmacy Practice Department, Byblos, Lebanon, 2Northwestern University Feinberg School of Medicine, CHICAGO, IL, USA, 3University of Illinois, Chicago, Chicago, IL, USA
1Lebanese American University, Associate Professor, Pharmacy Practice Department, Byblos, Lebanon, 2Northwestern University Feinberg School of Medicine, CHICAGO, IL, USA, 3University of Illinois, Chicago, Chicago, IL, USA
OBJECTIVES: Proxy assessments are commonly used in health-related quality of life research, yet the impact of proxy psychological distress on assessment accuracy remains poorly understood. This study examined whether proxy depression and pain affect agreement between proxy-reported and self-reported EQ-5D-5L domain and index scores.
METHODS: We analyzed data from 504 caregiver-care recipient dyads who completed bidirectional proxy assessments. Caregivers’ proxy-assessed patients' EQ-5D-5L scores, and care recipients’ proxy-assessed caregivers' EQ-5D-5L scores. Proxy distress was measured using EQ-HWB items with 7-day recall, categorized as none (level 1) versus any distress (levels 2 to 5, slight to most) for depression and pain items. Agreement was assessed using exact agreement percentages for individual domains and mean absolute difference (MAD) for utility scores. Chi-square tests and Mann-Whitney U tests compared agreement across distress severity groups.
RESULTS: Proxy depression significantly impaired proxy assessment accuracy in both directions. When proxies experienced any level of depression, utility MAD increased by 0.057-0.073 (p < 0.001), exceeding the minimally important difference threshold of 0.03-0.05. Exact agreement between proxy and self-report for each EQ-5D-5L domain decreased for Mobility, Self-Care, and Usual Activities, with the largest effect observed in Anxiety/Depression (57% → 42% for caregiver-to-care recipient assessments, p = 0.001; and 73% → 43% for care recipient-to-caregiver assessments, p < 0.001). In contrast, proxy pain showed no significant effect on overall utility agreement in either direction and minimal effects at the domain level. The Anxiety/Depression domain was most consistently affected by proxy depression across both assessment directions.
CONCLUSIONS: Proxy depression, but not pain, significantly impairs the accuracy of EQ-5D-5L proxy assessments. The effect is clinically meaningful, bidirectionally replicated, and particularly pronounced for the Anxiety/Depression domain. Researchers and clinicians using proxy-reported EQ-5D-5L data should consider screening for proxy mental health status.
METHODS: We analyzed data from 504 caregiver-care recipient dyads who completed bidirectional proxy assessments. Caregivers’ proxy-assessed patients' EQ-5D-5L scores, and care recipients’ proxy-assessed caregivers' EQ-5D-5L scores. Proxy distress was measured using EQ-HWB items with 7-day recall, categorized as none (level 1) versus any distress (levels 2 to 5, slight to most) for depression and pain items. Agreement was assessed using exact agreement percentages for individual domains and mean absolute difference (MAD) for utility scores. Chi-square tests and Mann-Whitney U tests compared agreement across distress severity groups.
RESULTS: Proxy depression significantly impaired proxy assessment accuracy in both directions. When proxies experienced any level of depression, utility MAD increased by 0.057-0.073 (p < 0.001), exceeding the minimally important difference threshold of 0.03-0.05. Exact agreement between proxy and self-report for each EQ-5D-5L domain decreased for Mobility, Self-Care, and Usual Activities, with the largest effect observed in Anxiety/Depression (57% → 42% for caregiver-to-care recipient assessments, p = 0.001; and 73% → 43% for care recipient-to-caregiver assessments, p < 0.001). In contrast, proxy pain showed no significant effect on overall utility agreement in either direction and minimal effects at the domain level. The Anxiety/Depression domain was most consistently affected by proxy depression across both assessment directions.
CONCLUSIONS: Proxy depression, but not pain, significantly impairs the accuracy of EQ-5D-5L proxy assessments. The effect is clinically meaningful, bidirectionally replicated, and particularly pronounced for the Anxiety/Depression domain. Researchers and clinicians using proxy-reported EQ-5D-5L data should consider screening for proxy mental health status.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
PCR40
Topic
Patient-Centered Research
Topic Subcategory
Patient Behavior and Incentives, Patient-reported Outcomes & Quality of Life Outcomes
Disease
No Additional Disease & Conditions/Specialized Treatment Areas