MULTI-COUNTRY CONTENT VALIDATION OF THE EQ-5D-5L + 4 BOLT-ON ITEMS WITHIN NON-SEGMENTAL VITILIGO
Author(s)
Adam Gibson, MSc, PhD1, Georges Dwyer, MSc1, Abbie Hurrell, BA2, Khaled Ezzedine, MD, PhD3, Viktoria Eleftheriadou, MD MRCP(UK) SCE(Derm)PhD4, Samantha K. Kurosky, MS5, Shailja Vaghela, MS, Pharma MBA, MPH5, Ernest H. Law, PharmD, PhD5, JIA MA, PhD6, Joseph C. Cappelleri, MPH, MS, PhD7, Pearl Craig, PharmD5, Louise Longworth, BSc, MSc, PhD1.
1Arrow Health Economics, London, United Kingdom, 2The Vitiligo Society, London, United Kingdom, 3Henri Mondor University Hospital and Universite Paris-Est Creteil Val, Paris, France, 4Vitiligo Clinical and Research Centre (Vitiligo CARE) for adult and paediatric patients, Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom, 5Pfizer, New York, NY, USA, 6Pfizer, Apex, NC, USA, 7Pfizer, Newington, CT, USA.
1Arrow Health Economics, London, United Kingdom, 2The Vitiligo Society, London, United Kingdom, 3Henri Mondor University Hospital and Universite Paris-Est Creteil Val, Paris, France, 4Vitiligo Clinical and Research Centre (Vitiligo CARE) for adult and paediatric patients, Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom, 5Pfizer, New York, NY, USA, 6Pfizer, Apex, NC, USA, 7Pfizer, Newington, CT, USA.
OBJECTIVES: When the EQ-5D-5L is not sensitive to important HRQoL impacts in specific patient populations, additional bolt-on dimensions can be added to the descriptive system. This research aimed to evaluate the content validity of the EQ-5D-5L with and without four bolt-on items (skin irritation, self-confidence, skin appearance, and social/relationship difficulties) for measuring HRQoL outcomes among adults with non-segmental vitiligo (NSV).
METHODS: Sixty adults with NSV across five European countries and the United States participated in individual, remote interviews. All items of the EQ-5D-5L were evaluated individually before reviewing all five as a whole, followed by an evaluation of each individual bolt-on, then the EQ-5D-5L and bolt-on items as a whole. Interview transcripts were analysed using thematic and content analytical methods.
RESULTS: All items were evaluated against 10 COSMIN criteria for good content validity of patient-reported outcome measures, including the three domains of relevance, comprehensiveness, and comprehensibility. Two EQ-5D-5L dimensions (usual activities, anxiety/depression) and all four bolt-on items individually demonstrated applicability to the HRQoL burden experienced by adults with NSV in terms of relevance. The EQ-5D-5L items, together, were evaluated as relevant for evaluating HRQoL in NSV patients by a minority of the sample (n=23), with the addition of the bolt-on items to the EQ-5D-5L evaluated as relevant by a majority (n=53). Both the EQ-5D-5L and the four bolt-on items were assessed favourably for comprehensibility. The EQ-5D-5L was suggested to be missing psychosocial outcomes of importance to NSV patients and the measurement of their HRQoL burden, with adults explicitly stating concepts found within the bolt-on items.
CONCLUSIONS: The EQ-5D-5L measure alone is suggested to be inadequate in terms of relevancy and comprehensiveness. The bolt-on items were assessed favorably using COSMIN criteria and criteria specific to bolt-on development, addressing concepts adults with NSV stated as missing from the original measure.
METHODS: Sixty adults with NSV across five European countries and the United States participated in individual, remote interviews. All items of the EQ-5D-5L were evaluated individually before reviewing all five as a whole, followed by an evaluation of each individual bolt-on, then the EQ-5D-5L and bolt-on items as a whole. Interview transcripts were analysed using thematic and content analytical methods.
RESULTS: All items were evaluated against 10 COSMIN criteria for good content validity of patient-reported outcome measures, including the three domains of relevance, comprehensiveness, and comprehensibility. Two EQ-5D-5L dimensions (usual activities, anxiety/depression) and all four bolt-on items individually demonstrated applicability to the HRQoL burden experienced by adults with NSV in terms of relevance. The EQ-5D-5L items, together, were evaluated as relevant for evaluating HRQoL in NSV patients by a minority of the sample (n=23), with the addition of the bolt-on items to the EQ-5D-5L evaluated as relevant by a majority (n=53). Both the EQ-5D-5L and the four bolt-on items were assessed favourably for comprehensibility. The EQ-5D-5L was suggested to be missing psychosocial outcomes of importance to NSV patients and the measurement of their HRQoL burden, with adults explicitly stating concepts found within the bolt-on items.
CONCLUSIONS: The EQ-5D-5L measure alone is suggested to be inadequate in terms of relevancy and comprehensiveness. The bolt-on items were assessed favorably using COSMIN criteria and criteria specific to bolt-on development, addressing concepts adults with NSV stated as missing from the original measure.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
PCR203
Topic
Clinical Outcomes, Methodological & Statistical Research, Patient-Centered Research
Topic Subcategory
Instrument Development, Validation, & Translation
Disease
Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain)