SPONSORED RESEARCH: Cross-Cultural Interpretation of EQ-HWB Response Options and Testing the EQ-HWB Modifications in a Multi-Country Mixed Patient Population
November 19, 2025
Read a Q&A Below
Assistant Professor Maja Kuharic, MPharm, Msc, PhD at Northwestern University's Feinberg School of Medicine Department of Medical Social Sciences (MSS) received two grants from the EuroQol Research Foundation, a leading international funder of research on the measurement and valuation of health, to further development of the EQ Health and Wellbeing (EQ-HWB) instrument.
Co-investigators include: A. Simon Pickard, PhD (University of Illinois Chicago), Jonathan Nazari, PhDc (University of Illinois Chicago), Ole Marten, PhD (University of Bielefeld, Germany), Wolfgang Greiner, PhD (University of Bielefeld, Germany), Aureliano Finch, PhD (European Medicines Agency/EuroQol Research Foundation), Zhihao Yang, PhD (Guizhou Medical University, China), Clara Mukuria, PhD (University of Sheffield), and Tessa Peasgood, PhD (University of Sheffield).
What is the EQ-HWB and why does it matter?
EQ-HWB is EuroQol's new measure of health, social care, and caregiver-related quality of life, designed to assess health and wellbeing across cross-culturally around the world. The instrument exists in two versions: a longer 25-item profile and a shorter 9-item version (EQ-HWB-9) suitable for economic evaluation.
Developed through the international "Extending the QALY" project led by the University of Sheffield and the EuroQol Research Foundation, the EQ-HWB addresses a recognized limitation in how we measure health outcomes for economic evaluation. Existing measures focus primarily on physical and mental health symptoms. However, many interventions—particularly that extend across social care and public health sectors—improve other important aspects of people's lives: autonomy, relationships, sense of purpose, and ability to participate in meaningful activities. The EQ-HWB captures these broader wellbeing dimensions and also measures impacts on informal caregivers, whose quality of life is often significantly affected by caring responsibilities but rarely measured, limiting our ability to assess the full impact of interventions.
The instrument is currently in experimental status and undergoing comprehensive international validation before routine use in health economic evaluation and resource allocation decisions worldwide.
What are the aims of the project?
The research program addresses two fundamental questions through complementary approaches.
The first project investigates how people interpret response options across the EQ-HWB's three distinct types of response scales—frequency scale ("not at all" to "most or all of the time"), severity scale ("mild" to "very severe"), and difficulty scale ("no difficulty" to "unable") in found countries (US, UK, Germany and China).
The second project tests specific modifications to the EQ-HWB-9 items and wording that emerged from initial validation studies. Initial testing suggested opportunities to refine certain items and clarify distinctions between response options. Using cognitive debriefing interviews across diverse population of patients, caregivers and social care users in three countries (US, Germany, Netherlands), the team is testing whether proposed modifications improve clarity and cross-cultural equivalence.
How are Response Options Scales Understood Across Countries and Cultures?
The EQ-HWB uses three different response scales across its items—frequency ("not at all" to "most or all of the time"), severity ("mild" to "very severe"), and difficulty ("no difficulty" to "unable"). A key question for cross-cultural validation is whether these terms function equivalently across languages and cultures: Does "sometimes" mean the same thing in English, Chinese, and German? Does "moderate pain" represent the same intensity across different populations?
These mixed response formats also have implications for valuation. For health state valuation methods like time trade-off and discrete choice experiments, respondents evaluate health states described using these response levels. If response options are not clearly ordered—for example, if "moderate" and "some" are interpreted as similar in severity, or if their ordering is reversed—this can lead to preference inversion, where respondents' valuations don't align with the intended ordering of health states. Understanding whether response levels maintain their intended progression is critical for generating reliable health state values.
Using surveys with participants across the UK, US, China, and Germany, the team is quantifying how people assign numerical meaning to terms like "sometimes" or "moderate difficulty" across four countries (UK, US, China, Germany), examining whether these terms function equivalently across languages and cultures. This evidence will inform which response formats work best for reliable future valuation studies.
How will EQ-HWB-9 Item Modifications be tested?
The second project is part of a coordinated multi-country research program, with parallel qualitative studies being conducted in ten countries (Argentina, China, Germany, Hungary, Slovenia, Ireland, Indonesia, Netherlands, United Kingdom, and United States). Kuharic coordinates this international effort and serves as Co-Principal Investigator for the US, Germany, and Netherlands studies, where her team is conducting cognitive debriefing interviews with mixed patient populations, caregivers, and social care users. These cognitive debriefing interviews systematically explore how participants understand and interpret the modified items and response options, whether the changes improve clarity across different languages and cultures, and whether the modifications maintain the intended meaning of what is being measured.
This qualitative evidence from the coordinated multi-country program will help determine whether the proposed changes improve the instrument.
What are your next steps?
The Response Option Interpretation study is now collecting data across all four countries, with completion expected by end of 2025. The team will analyze how different cultural and linguistic groups interpret the response options. The Modifications Testing study is conducting interviews in waves across the three countries. This approach allows the team to refine their questions as they learn from earlier interviews. Both studies will come together in spring 2026 to provide recommendations to the EuroQol Foundation about the best response formats and item wording for the final EQ-HWB instrument.
What do you hope will come out of this funded research?
This research will directly shape the final EQ-HWB-9 instrument used in health economic evaluations worldwide. Our findings will provide empirical evidence for selecting which response scales work best across cultures and whether proposed item modifications improve comprehension and validity.
Ultimately, this work strengthens the foundation for broader wellbeing measurement in health economics. By validating an instrument designed to integrate health, social care, and caregiver outcomes, the team is helping ensure the EQ-HWB-9 meets the rigorous standards required for global implementation in economic evaluation and cross-sector resource allocation decisions. “This work exemplifies the Department of Medical Social Sciences
commitment to internationally collaborative measurement science that transforms patient-centered outcomes assessment, and we are proud of Maja’s leadership in advancing this important work,” said department chair Rinad Beidas, PhD. Congratulations Maja!