Abstract
Objective. Aspects of antineutrophil cytoplasmic antibodies–associated vasculitis (AAV) prioritized by patients with AAV were described using the International Classification of Function, Disability, and Health (ICF).
Methods. Items identified during 14 individual interviews were incorporated into an ICF-based questionnaire administered to participants of 2 vasculitis patient symposia: 36 in the United Kingdom and 63 in the United States.
Results. Categories identified as at least “moderately relevant” by ≥ 5% of subjects included 44 body functions, 14 body structures, 35 activities and participation, 31 environmental factors, and 38 personal factors.
Conclusion. Identified categories differ from those identified by the current Outcome Measures in Rheumatology (OMERACT) core set and those prioritized by vasculitis experts.
The vasculitides are a group of heterogeneous conditions characterized by inflammation of blood vessels. Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) are small vessel vasculitides that include granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic GPA (EGPA). AAV can affect practically any organ system, with manifestations ranging from diseases of the ears, nose, and sinuses to life-threatening failure of kidneys, lungs, or heart.
Outcome Measures in Rheumatology (OMERACT) is an international organization that strives to develop data-driven, optimal outcome measures for use in clinical trials1. In 2010, OMERACT endorsed a core set of outcome measures for ANCA-associated vasculitis2. Subsequently, a framework was developed for the selection of areas and domains that should be assessed in clinical trials, referred to as the OMERACT Filter 2.0 framework1,3; it calls for inclusion of a range of stakeholders, especially patients, into the process of outcome measure development.
The OMERACT Vasculitis Working Group has conducted several projects aimed at updating and expanding the existing expert-driven OMERACT core set for AAV4,5, including this project, which uses the International Classification of Function, Disability and Health (ICF). The ICF is a general health status framework6 that views health as a broad concept shaped by the relationship between various ICF components: impairments of body functions and body structures, limitations of activities, restrictions of participation, and the influence of environmental and personal contextual factors6. The ICF also offers a classification system to describe functioning and health using categories organized into a 4-level hierarchically nested structure6. The OMERACT initiative endorsed the ICF as a tool to identify and classify (sub)domains relevant to measurement of outcomes for a specific medical condition1.
This manuscript describes the ICF-based analysis of aspects of health prioritized by patients with AAV.
MATERIALS AND METHODS
The study consisted of 2 parts, both overseen by a steering committee composed of content experts, methodologists (including qualitative experts), and patients with AAV. The research received approval from the Ottawa Hospital’s Research Ethics Board (protocol #20120604-01H and #20150189-01H), and all participating patients gave informed consent.
The first, qualitative part of the study consisted of a series of individual semistructured interviews conducted with English-speaking adult patients with AAV at the Ottawa Hospital in Ottawa, Ontario, Canada, and the Nuffield Orthopaedic Centre in Oxford, UK. A purposive sampling strategy was used to select interviews for our study and aimed at including patients with each of the 3 types of AAV, with different severities, and at different stages of disease7; interviews were performed until saturation of the identified concepts was reached8.
Interviews were audio recorded, professionally transcribed, and all basic concepts were “linked” to the most precise ICF category according to previously established ICF linking rules by Cieza, et al9,10, and then summarized on the second ICF level, as we described previously11. Because personal factors are currently not classified by the ICF, the general scheme proposed by Geyh, et al12 was followed. It divides the personal factors into 3 broad groups: (1) “facts” about the individual’s position in the physical, social, and temporal context, (2) “experience” of the concept in question (feelings, thoughts, beliefs, and motives), and (3) “patterns” of experience and behavior including personality traits and habits.
In the second part of the study, categories identified through the qualitative analysis were incorporated into an ICF-based questionnaire that was administered to participants of 2 vasculitis patient symposia: the International Vasculitis and ANCA Workshop in London, UK, April 18, 2015, and the Vasculitis Foundation symposium in Jacksonville, Florida, USA, June 19–21, 2015. Participants rated the relevance of each listed category on a standardized ordinal scale associated with the ICF classification6. The physiologic effects of vasculitis and its effects on patients’ activities were rated on a 5-level scale from 0 to 4 with the following categories: “no effect,” “mild,” “moderate,” “severe,” and “complete impairment.” The relevance of environmental and personal factors was rated on a 9-level scale from −4 (“extreme negative effect on health”), through the same gradations to 0 (“no effect”), and then to +4 (“extreme positive effect”). Factors that have at least “moderate” effect for at least 5% of respondents were selected, as suggested previously13.
RESULTS
Fourteen individual interviews (10 from Ottawa, Ontario, Canada, and 4 from Oxford, UK) were available for the qualitative portion of the study. Participants identified a wide range of important aspects of AAV that were linked to 159 ICF categories.
The underlying qualitative findings were incorporated into a questionnaire administered to about 100 participants at each of the 2 vasculitis patient symposia described above; 51 and 74 patients from the United Kingdom and United States returned the questionnaire, and 36 and 63 (respectively) had AAV and were included in this analysis. Participants’ demographic and clinical characteristics are summarized in Appendix 1; the respondents’ disease spectrum was representative of a general population of patients with AAV.
All the categories presented in the questionnaire were rated as at least “moderately relevant” by at least 5% of subjects. This includes 44 second-level categories in the ICF component body functions, 14 in body structures, 35 in activities and participation, 31 in environmental factors, and 38 in personal factors. A subset of the most relevant categories, ranked as at least “moderately relevant” by at least 30% of participants, is summarized in Table 1, Table 2, and Table 3.
Categories from the International Classification of Function (ICF) compenents Body Functions, Body Structures, and Activities and Participation identified as at least moderately important by at least 30% of participants.
International Classification of Function (ICF) Environmental Factors identified as at least moderately relevant by at least 30% of participants.
International Classification of Function (ICF) Personal Factors identified as at least moderately relevant by at least 30% of participants.
A greater proportion of participants from the United States compared to the United Kingdom reported financial situation and healthcare system issues, such as access to medications, as relevant to their health (38% and 60% vs 19% and 44%, respectively). Similarly, more American participants reported positive effects of having vasculitis (personal factors → experience of vasculitis), including increased appreciation of life, increased sensitivity to other people’s misfortunes, and increasing activities related to helping others (72%, 73%, and 64% vs 42%, 36%, and 39%, respectively). In contrast, the effect of the vasculitis on patients’ ability to travel (activities and participation → recreation and leisurely activities) was reported as at least moderately relevant by 61% of participants from the United Kingdom compared to 29% of Americans.
Similar analyses by type of AAV demonstrated expected trends: more respondents with EGPA reporting an effect of their disease on the heart and lungs and a prominent effect of air quality (consistent with asthma being a central feature of the disease); subjects with MPA had the most difficulty with blood pressure and kidneys. Further, subjects with MPA seemed to be most affected by the various aspects of their psychosocial functions, including mental functions (motivation, appetite, concentration, and emotions); domestic, community, and social life (activities and participation); and interpersonal interactions and relationships (environmental factors).
DISCUSSION
In our analysis mainly limited by the narrow geographic sampling, the ICF was a useful framework for describing aspects of AAV relevant to patients. Comparisons of prioritized items by country of residence and by diagnosis revealed that while the majority of differences between the 3 different forms of AAV were in keeping with the expected differences in the frequencies of specific organ involvement, most variability between the 2 participating countries was seen in the importance of various contextual factors. As the role of contextual factors in interpreting outcome measures continues to be clarified14, considering some key contextual factors will deepen the ability to fully assess the effect of AAV and other diseases.
An earlier ICF-based analysis of the current OMERACT Core Set for AAV11 revealed that it does not measure the whole spectrum of limitations in activities and participation prioritized by patients in this study. In addition, it covers only a small number of environmental and personal factors, likely because contextual factors have only recently become recognized as relevant for interpreting the measured outcomes14. The areas under-sampled by the core set were also found to be less important to vasculitis clinical experts in a recent ICF-based analysis15; this is not surprising, given that the composite tools that constitute the current OMERACT core set for AAV were designed by the same clinical experts. Notably, the few contextual factors that clinicians did identify as important differ from those prioritized by patients: clinicians focus on hard “objective” factors such as demographics, comorbidities, availability of health services, and social support15, while the range of factors identified by patients is much broader and dominated by the more subjective factors such as attitudes of other people and patients’ own reactions and thoughts. In contrast, several of the more severe disease manifestations of AAV, such as lung and kidney involvement, visual impairment, and hearing loss, which are prioritized by the majority of vasculitis clinical experts15, were rated as at least “moderately relevant” by < 50% of patient participants, likely reflecting the frequency of these manifestations in the cohort. Along with similar findings in other studies16, the observed differences in perspectives of patients and clinicians support OMERACT’s recommendation to include perspectives of different stakeholders, including patients, into the process of development of core sets of domains and outcome measures1. To comply with these standards, the OMERACT Vasculitis Working Group is working to update the current OMERACT core set for AAV.
Acknowledgment
The authors appreciate the assistance and advice of Susan Humphrey-Murto, Joyce Kullman, John Mills, Susan Mills, and C. Douglas Smith.
APPENDIX 1.
Demographic characteristics of participants. Values are n (%) unless otherwise specified.
- Accepted for publication January 9, 2019.
