Which dimensions of disability does the HIV Disability Questionnaire (HDQ) measure? A factor analysis

Abstract

Purpose: To assess the dimensions of disability measured by the HIV Disability Questionnaire (HDQ), a newly developed 72-item self-administered questionnaire that describes the presence, severity and episodic nature of disability experienced by people living with HIV. Methods: We recruited adults living with HIV from hospital clinics, AIDS service organizations and a specialty hospital and administered the HDQ followed by a demographic questionnaire. We conducted an exploratory factor analysis using disability severity scores to determine the domains of disability in the HDQ. We used the following steps: (a) ensured correlations between items were >0.30 and <0.80; (b) conducted a principal components analysis to extract factors; (c) used the Scree Test and eigenvalue threshold >1.5 to determine the number of factors to retain; and d) used oblique rotation to simplify the factor loading matrix. We assigned items to factors based on factor loadings of >0.30. Results: Of the 361 participants, 80% were men and 77% reported living with at least two concurrent health conditions in addition to HIV. The exploratory factor analysis suggested retaining six factors. Items related to symptoms and impairments loaded on three factors (physical [20 items], cognitive [3 items], and mental and emotional health [11 items]) and items related to worrying about the future, daily activities, and personal relationships loaded on three additional factors (uncertainty [14 items], difficulties with day-to-day activities [9 items], social inclusion [12 items]). Conclusions: The HDQ has six domains: physical symptoms and impairments; cognitive symptoms and impairments; mental and emotional health symptoms and impairments; uncertainty; difficulties with day-to-day activities and challenges to social inclusion. These domains establish the scoring structure for the dimensions of disability measured by the HDQ.

Implications for Rehabilitation

• As individuals live longer and age with HIV, they may be living with the health-related consequences of HIV and concurrent health conditions, a concept that may be termed disability. Measuring disability is important to understand the impact of HIV and its comorbidities.

• The HIV Disability Questionnaire (HDQ) is a self-administered questionnaire developed to describe the presence, severity and episodic nature of disability experienced by people living with HIV. The HDQ is comprised of six domains of disability including: physical symptoms and impairments (20 items); cognitive symptoms and impairments (3 items); mental and emotional health symptoms and impairments (11 items); uncertainty (14 items); difficulties with day-to-day activities (9 items) and challenges to social inclusion (12 items). These domains represent the dimensions of disability measured by the HDQ.

• The HDQ is the first known HIV-specific disability measure for adults living with HIV. The HDQ may be used by clinicians and researchers to assess disability experienced by adults living with HIV.

• Factor analysis
• HIV/AIDS
• HIV Disability Questionnaire

Acknowledgements

We acknowledge Marilyn Swinton for her contributions with recruitment and data collection as Research Coordinator on this phase of the HIV Disability Questionnaire Study. We gratefully acknowledge the members of the Community Advisory Committee including Ken King (Canadian Working Group on HIV and Rehabilitation), James Murray (Ontario Ministry of Health and Long-Term Care), Rob Alexander (HIVER Consulting) and Shane Patey (Toronto People with AIDS Foundation) for their contributions to this work. We gratefully acknowledge Community Collaborators in this work including Casey House, Toronto People with AIDS Foundation, Canadian Working Group on HIV and Rehabilitation, McMaster Special Immunology Services (SIS) Clinic, the AIDS Network (Hamilton), AIDS Niagara, AIDS Committee of Durham Region, and AIDS Committee of Toronto.

Declaration of interest

This research was supported by an operating grant from the Canadian Institutes of Health Research (CIHR) HIV/AIDS Community Based Research Program (CBR#104072). Dr. Kelly O’Brien was supported by a Fellowship from the CIHR, HIV/AIDS Research Program and Michael G. DeGroote post-doctoral fellowship (McMaster University). Dr. Ahmed Bayoumi was supported by a Canadian Institutes of Health Research/Ontario Ministry of Health and Long-Term Care Applied Chair in Health Services and Policy Research. The Centre for Research on Inner City Health is supported in-part by a grant from the Ontario Ministry of Health and Long-Term Care. The views expressed in this article are those of the authors, and no official endorsement by supporting agencies is intended or should be inferred.