Developing a short-form version of the HIV Disability Questionnaire (SF-HDQ) for use in clinical practice: a Rasch analysis

Abstract

Background Disability is an increasingly important health-related outcome to consider as more individuals are now aging with Human Immunodeficiency Virus (HIV) and multimorbidity. The HIV Disability Questionnaire (HDQ) is a patient-reported outcome measure (PROM), developed to measure the presence, severity and episodic nature of disability among adults living with HIV. The 69-item HDQ includes six domains: physical, cognitive, mental-emotional symptoms and impairments, uncertainty and worrying about the future, difficulties with day-to-day activities, and challenges to social inclusion. Our aim was to develop a short-form version of the HIV Disability Questionnaire (SF-HDQ) to facilitate use in clinical and community-based practice among adults living with HIV. Methods We used Rasch analysis to inform item reduction using an existing dataset of adults living with HIV in Canada (n = 941) and Ireland (n = 96) who completed the HDQ (n = 1037). We evaluated overall model fit with Cronbach’s alpha and Person Separation Indices (PSIs) (≥ 0.70 acceptable). Individual items were evaluated for item threshold ordering, fit residuals, differential item functioning (DIF) and unidimensionality. For item threshold ordering, we examined item characteristic curves and threshold maps merging response options of items with disordered thresholds to obtain order. Items with fit residuals > 2.5 or less than − 2.5 and statistically significant after Bonferroni-adjustment were considered for removal. For DIF, we considered removing items with response patterns that varied according to country, age group (≥ 50 years versus < 50 years), and gender. Subscales were considered unidimensional if ≤ 5% of t-tests comparing possible patterns in residuals were significant. Results We removed 34 items, resulting in a 35-item SF-HDQ with domain structure: physical (10 items); cognitive (3 items); mental-emotional (5 items); uncertainty (5 items); difficulties with day-to-day activities (5 items) and challenges to social inclusion (7 items). Overall models’ fit: Cronbach’s alphas ranged from 0.78 (cognitive) to 0.85 (physical and mental-emotional) and PSIs from 0.69 (day-to-day activities) to 0.79 (physical and mental-emotional). Three items were rescored to achieve ordered thresholds. All domains demonstrated unidimensionality. Three items with DIF were retained because of their clinical importance. Conclusion The 35-item SF-HDQ offers a brief, comprehensive disability PROM for use in clinical and community-based practice with adults living with HIV.

Examining the Utility of the HIV Disability Questionnaire (HDQ) in Clinical Practice: Perspectives of People Living with HIV and Healthcare Providers

“… 40 Research is currently underway to develop a short-form version of the HDQ. 41 Participants, particularly healthcare providers, also described the importance of score interpretability of the HDQ. Future research should prioritize developing a quick and user-friendly scoring system of the HDQ that can be easily interpreted by healthcare providers to guide treatment decisions.…”

Problems undermining the health-related quality of life of people living with HIV in Spain: a qualitative study to inform the development of a novel clinic screening tool

“…The eight domains of the 24-item instrument closely reflect literature review and FGD findings (Box 1 ) [ 40 ]. Commonalities and differences can be observed when the CST-HIV is compared to two other short, broadly focused PROMs developed to support the clinical care of PLHIV: the Positive Outcomes PROM and the Short-Form HIV Disability Questionnaire (SF-HDQ) [ 39 , 85 ]. The framing of the SF-HDQ in terms of disability may seem to imply a narrower purpose for this instrument compared to the two others, but in fact the developers of the SF-HDQ based their work on a highly comprehensive definition of HIV-associated disability as “a combination of physical, cognitive, mental and emotional symptoms and impairments; difficulties carrying out day-to-day activities; challenges to social inclusion; and uncertainty about future health” [ 86 ].…”

“…Given the many potential health-related challenges facing PLHIV, time and logistical constraints point to the need for short broadly-focused PROMs that can be used to identify multiple types of issues in routine clinical care. Researchers have reported on the development of two such instruments in recent years, with one informed by qualitative research in the United Kingdom and Ireland, and the other informed by qualitative research in Canada [ 38 , 39 ]. It is not known to what extent these instruments capture the health-related concerns of PLHIV in countries with different social, cultural, epidemiological and health system dynamics.…”

Long COVID and episodic disability: advancing the conceptualisation, measurement and knowledge of episodic disability among people living with Long COVID – protocol for a mixed-methods study

“…We will conduct Rasch analysis, a preferred method for developing PROMs, assessing structural and cross-cultural validity, and for establishing an interval-level scale 73–76. We will use criteria for model fit similarly used in our SF-HDQ development54: Cronbach’s alpha (internal consistency reliability (≥0.8 acceptable),77 and Person Separation Indices (≥ 0.70 acceptable),78 individual item fit using item threshold ordering, fit residuals (residuals >|2.5|),79 80 differential item functioning (country, age, sex, gender)74 and unidimensionality 81. We will create a user-friendly scoring algorithm to convert raw summed EDQ scores to the equivalent Rasch-based person logit scores rescaled (0–100) with higher scores indicating greater severity of disability 82…”

“…The HDQ possesses reliability and validity for use with adults living with HIV in Canada, Ireland, UK, and USA 50–53. Recently, our team used modern psychometric (Rasch) and community-engaged approaches to establish a Short-Form version (SF-HDQ) to enhance the feasibility, electronic administration and immediate scoring for use in clinical and community settings 54. The lessons learnt in HIV, disability and rehabilitation, specifically our work in Episodic Disability and PROM development provides a foundation for conceptualising and measuring Episodic Disability in the context of Long COVID 33…”