What are the key domains of HRQoL defined by children with impaired mobility and their parents, in relation to wheelchair use and mobility impairment?
economic evaluation to wheelchair interventions|health care nursing
Defining health-related quality of life for young wheelchair users:
Abstract
Background
Wheelchairs for children with impaired mobility provide health, developmental and psycho-
social benefits, however there is limited understanding of how mobility aids affect the health-
related quality of life of children with impaired mobility. Preference-based health-related
quality of life outcome measures are used to calculate quality-adjusted life years; an impor-
tant concept in health economics. The aim of this research was to understand how young
wheelchair users and their parents define health-related quality of life in relation to mobility
impairment and wheelchair use.
Methods
The sampling frame was children with impaired mobility (?18 years) who use a wheelchair and their parents. Data were collected through semi-structured face-to-face interviews con-
ducted in participants homes. Qualitative framework analysis was used to analyse the inter-
view transcripts. An a priori thematic coding framework was developed. Emerging codes
were grouped into categories, and refined into analytical themes. The data were used to
build an understanding of how children with impaired mobility define health-related quality of
life in relation to mobility impairment, and to assess the applicability of two standard mea-
sures of health-related quality of life.
Results
Eleven children with impaired mobility and 24 parents were interviewed across 27 inter-
views. Participants defined mobility-related quality of life through three distinct but interre-
lated concepts: 1) participation and positive experiences; 2) self-worth and feeling fulfilled;
3) health and functioning. A good degree of consensus was found between child and parent
responses, although there was some evidence to suggest a shift in perception of mobility-
related quality of life with child age.
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OPENACCESS
Citation: Bray N, Noyes J, Harris N, Edwards RT (2017) Defining health-related quality of life for young wheelchair users: A qualitative health economics study. PLoS ONE 12(6): e0179269. https://doi.org/10.1371/journal.pone.0179269
Editor: Yih-Kuen Jan, University of Illinois at Urbana-Champaign, UNITED STATES
Received: February 24, 2017
Accepted: May 27, 2017
Published: June 15, 2017
Copyright: © 2017 Bray et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability Statement: Data are protected for patients confidentiality. Qualitative interview participants did not consent to have their full transcripts made publicly available. Anonymised data and interview transcripts are available from the Centre for Health Economics and Medicines Evaluation (CHEME, Ardudwy Hall, Bangor University, Bangor, Gwynedd, UK, LL57 2PZ; cheme@bangor.ac.uk; +44 1248 382153). Please contact Dr. Nathan Bray (n.bray@bangor.ac.uk) for access.
Conclusions
Young wheelchair users define health-related quality of life in a distinct way as a result of
their mobility impairment and adaptation use. Generic, preference-based measures of
health-related quality of life lack sensitivity in this population. Development of a mobility-
related quality of life outcome measure for children is recommended.
Introduction
Prevalence of childhood disability and mobility impairment
Approximately 5% of children have some form of disability; globally 95 million children aged 14 or under are believed to have a disability [1]. In the United Kingdom (UK) 800,000 children and young people have a disability [2]. Mobility impairment is one of the leading causes of dis- ability [3]. The National Health Service (NHS) is the largest supplier of wheelchairs and mobil- ity aids in the UK, supporting over 1.2 million people with long-term mobility needs [4], around 70,000 of which are children [5].
Independent mobility offers a range of holistic benefits for children with impaired mobility, including functional mobility improvement [6], psychosocial development [7], increased inde- pendence [8] and reduced pain and deformity [9]. Appropriate wheelchair interventions are key to improving the outcomes of children with impaired mobility, including their health- related quality of life (HRQoL).
Defining health-related quality of life
HRQoL is the perceived impact of health status on quality of life (QoL), including physical, psychological and social functioning [10]. Varni et al [11] found that, of the chronic conditions they evaluated, cerebral palsy had the most significant impact on the HRQoL of children. Var- gus-Adams [12] and Dobhal et al [13] found that cerebral palsy predominantly impacts child HRQoL in the domains of physical function, physical independence, mobility and social inte- gration. Wheelchair provision has been found to improve quality of life (QoL) [5,14] and more specifically HRQoL [15], however further research is required.
Quality-adjusted life year framework
In the UK the National Institute for Health and Care Excellence (NICE) provides independent, evidence-based guidance to the NHS to inform healthcare funding allocation. At present there is limited robust economic evidence to inform NHS wheelchair provision and the design of NHS wheelchair services in an evidence-based manner [16]. Likewise, published evidence of paediatric wheelchair effectiveness tends to lack methodological quality [17].
Evidence-based decision-making requires robust evidence of cost-effectiveness to ensure that limited resources are used in a way that maximises potential benefits for patients [18]. NICE recommend the Quality-Adjusted Life Year (QALY) as a primary outcome measure in cost-effectiveness analysis [19]. QALYs represent an aggregate score of quantity and quality of life; they are calculated by multiplying the amount of time spent in a given health state by the relative societal preference for that health state. Due to their generic nature, QALYs can be used to compare disparate interventions and patient groups [20]. Health state preferences, or utilities, are derived from preference-based measures of HRQoL, therefore in order to calculate QALYs, robust preference-based HRQoL data is required.
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Funding: The study was funded by the National Institute for Social Care and Health Research (NISCHR; now called Health and Care Research Wales) as part of a PhD studentship award. The funding organisation had no role in the design, conduct, analysis or interpretation of this research.
Competing interests: The authors have declared that no competing interests exist.
Abbreviations: CHU-9D, Child health utility nine dimension; COREQ, Consolidated criteria for reporting qualitative research; EQ-5D, EuroQoL five dimension; EQ-5D-Y, EuroQoL five dimension youth version; HRQoL, Health-related quality of life; HUI, Health utilities index; NHS, National Health Service; NICE, National Institute for Health and Care Excellence; PIADS, Psychosocial Impact of Assistive Devices Scale; PWC, Powered wheelchair; QALY, Quality-adjusted life year; QoL, Quality of life; UK, United Kingdom.
Preference-based health-related quality of life measurement
Preference-based approaches to HRQoL measurement are distinct as each combination of answers, representing a specific health state, is assigned a utility weight derived from the social desirability of that state, for instance ranging from death (0) to perfect health (1). Health state preferences are usually elicited from a large sample of the general population, and thus results reveal societal preferences for configurations of health. NICE stipulate that in the calculation of QALYs, preference weights must derive from a representative general population sample as societal resources should be allocated in a way that is relevant to the general population [21].
There is considerable debate regarding the use of patient or public preferences for health state valuation [22]. When assessing the desirability of hypothetical health states, individuals focus on the transition from their own health state to the hypothetical health state, and thus general population beliefs about the impact of disease and disability do not always reflect the lived experience [23,24]. When disability is presented to a member of the general public in the form of a hypothetical health state, the focus on personal transition means that processes of adaptation to health states are not accounted for, and thus there is a misunderstanding of the lived experience of disability [22].
Versteegh and Brouwer [22] state that differences in patient and public health state prefer- ences reveal important information about perceived QoL. They conclude that both patient and general public preferences are valid sources of health state utilities, and therefore cost per QALY estimates should be calculated from the utility weights of both groups where possible.
Applying methods of economic evaluation to wheelchair interventions
To date a small number of economic analyses of wheelchair interventions have been con- ducted [2529], however these tend to lack methodological quality and nearly all focus on adults. Evidently there is a need for more high quality robust economic evidence, and appro- priate data collection methods, to facilitate an evidence based approach to paediatric wheel- chair provision. Some existing assistive technology outcome measures do approximate HRQoL measurement to a certain extent, for instance the Psychosocial Impact of Assistive Devices Scale (PIADS) has been found to be a robust psychosocial impact measure for assistive technology users [30], but it is neither preference-based nor directly measuring HRQoL constructs.
NICE and the QALY framework have become increasingly influential in UK healthcare. It is therefore important to generate data which adheres to NICE guidelines to ensure that it is comparable and informative in decisions about healthcare funding. This requires an under- standing of how to apply methods of QALY calculation in specific contexts, such as paediatric wheelchair provision. This first requires an understanding of how young wheelchair users define HRQoL in relation to mobility impairment and wheelchair use (i.e. mobility-related QoL) in order to assess the appropriateness of NICE approved HRQoL measures, such as the EuroQoL Five Dimension (EQ-5D) [31].
Factors such as independence, socialisation, acceptance and integration are of particular importance to wheelchair users [8,14,3234]. The ability of commonly used generic HRQoL outcome measures to accurately capture these domains in this specific population is unknown. There are currently no preference-based approaches to measuring HRQoL which have been developed specifically for use in mobility-impaired populations. Furthermore, generic prefer- ence-based measures appear to have limited sensitivity in the context of mobility impairment [35]. Previous researchers have resorted to amending the wording of the EQ-5D to increase relevance to people who use wheelchairs [36]; although pragmatic, this is not a valid use of such measures.
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Aim and research questions
The aim of this study was to determine how children with impaired mobility and their families define HRQoL and mobility-related QoL in relation to wheelchair use and mobility impairment. Furthermore, we sought to examine the applicability of standard HRQoL mea- sures in this population, particularly those endorsed by NICE (i.e. EQ-5D) and designed spe- cifically for use in children (i.e. Health Utilities Index (HUI) [37]). Research questions:
1. What are the key domains of HRQoL defined by children with impaired mobility and their parents, in relation to wheelchair use and mobility impairment?
2. To what extent do generic HRQoL measures reflect how children with impaired mobility and their parents define HRQoL in relation to wheelchair use and mobility impairment?
Materials and methods
Design and methodology
An exploratory descriptive study design was utilised. Data were collected through qualitative semi-structured interviews with young wheelchair users (?18 years), their parent(s) or dyads of young wheelchair users and their parent(s). Qualitative Framework analysis was used to analyse the interview transcripts [38]. Qualitative Framework analysis is a popular approach in health-related research as it can be used to meet specific information needs [39]. Deductive a priori methods allows specific themes and issues to be examined in targeted populations using pre-specified aims and objectives [40]. In the context of health-related research this allows researchers to focus on a particular area of interest or phenomena, whilst maintaining system- atic and transparent processes [41].
The study reported in this paper was part of a larger programme of research called the Wheels Project (funded by the National Institute for Social Care and Health Research PhD Studentship award), which also included a systematic review [16], quantitative assessment of HRQoL (paper in preparation) and a pilot discrete choice experiment questionnaire [42]. This paper presents only the qualitative findings.
This study was granted ethical approval by the North West Wales NHS research ethics com- mittee (reference: 13/WA/0143) and an academic ethics committee at Bangor University.
For the purpose of this paper child is defined as anyone aged 18 or under. The United Nations Convention on the Rights of the Child states that a child is any person under the age of 18 years [43]. Individuals aged up to 18 years were included in this research to be inclusive of individuals transitioning from child to adult wheelchair services. Although it is somewhat problematic to refer to teenagers and young adults as children, using a single term improves clarity within the paper. The term mobility-related QoL refers specifically to the impact of mobility impairment and wheelchair use on HRQoL.
Data collection
Face-to-face semi-structured interviews were conducted in participants homes, guided by an interview schedule (S1 File). The interview schedule was piloted with a small sample (N = 10) of young wheelchair users (aged 11 to 18) at a childrens wheelchair charity beneficiary meet- ing in order to gauge their understanding of the questions and to refine the wording.
Each interview lasted for around an hour. The interview schedule was developed from a number of sources: the findings of a previous systematic review [16]; discussion within the research team; and with consideration of the EQ-5D-Y and HUI HRQoL measures. The ques- tions facilitated participants to consider how they define HRQoL in relation to wheelchair use
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and mobility impairment, and to reflect on the ability of standard HRQoL measures to repre- sent this definition. This included asking participants to discuss the domains and levels of the EQ-5D-Y and HUI measures in relation to their own definition of HRQoL. Parents were asked to discuss health and QoL in relation to their child.
The EQ-5D-Y and HUI measures were used to frame the interviews as they are two of the most commonly used generic preference-based HRQoL measures. The EQ-5D is recom- mended by NICE for use in cost-effectiveness analysis [44], and the HUI was the only prefer- ence-based HRQoL measure designed specifically for use in children and adolescents at the time of designing the study.
The EQ-5D-Y measures HRQoL using five domains: mobility; self-care; usual activities; pain and discomfort; and anxiety and depression [31]. The EQ-5D was originally developed for use in adult populations. A child version, the EQ-5D-Y, has been validated for proxy reporting from age four [45] and child self-reporting from age eight [46]. EQ-5D respondents are asked to rate their health on each domain using one of three possible responses: no prob- lems, some problems, a lot of problems. A 5-level version of the EQ-5D has been validated in adults, but not children [47].
The HUI contains the HUI2 and HUI3 systems [37]. It comprises a 15-question self-com- pletion questionnaire, with each question presenting between four and six possible responses (i.e. levels). The HUI covers a range of HRQoL domains, including: sensation, speech, mobil- ity, dexterity, emotion, cognition, self-care and pain. It is validated for proxy use from age five, and child self-reporting from age eight [37].
Recruitment and sampling
The sampling frame was young wheelchair users (?18 years) with long term mobility impair- ments and their parent(s). The sample was stratified by the age of the child (05 years; 615 years; 1618 years) and interviewee structure (child; parent; child/parent dyad). Potential par- ticipants were sent postal information about the study and indicated their consent to partici- pate by returning a completed demographics questionnaire (which contained an initial consent/assent form). A date and time for a face-to-face interview was then arranged via a tele- phone follow-up. Participants were recruited between June and October 2013 from three recruitment sites: an NHS wheelchair service, a charity powered wheelchair (PWC) manufac- turer/supplier and a childrens wheelchair charity.
Before beginning the interview the study was explained in full to participants. Participants completed a second consent/assent form to indicate that they understood the purpose of the study and agreed to take part in the interview. Children under the age of 16 completed an assent form and their parents completed a proxy consent form.
Response rate and sample size
A total of 125 study packs were distributed across England and Wales by the three recruitment sites. 38 initial HRQoL/demographic questionnaires were returned (initial response rate of 30.4%). Of the 38 child/parent dyads invited to take part in the interview ten declined. 27 inter- views were conducted (one of which contained two child participants from the same family), giving a secondary response rate of 73.7%. An overall interview response rate of 22.4% [N = 28] was observed for all of the 125 invitation packs sent out.
In total 17 parents decided to take part on their own, either because their child was too young to participate [N = 12; all under 5s] or because they felt that it was not suitable for their child [N = 5; all 6 to 15 year olds]. Four children over the age of 16 took part on their own and
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seven child/parent dyads took part in the interview together. In total 24 parents and 11 chil- dren were interviewed. Full disclosure of demographic details are presented in Tables 1 and 2.
Data handling and analysis
Each interview was transcribed verbatim. Identifiable data were deleted from the transcripts to maintain confidentiality. Transcripts were not returned to participants for comments or cor- rections due to time constraints. The software nVivo v9.2 was used for qualitative data handling.
An a priori thematic coding framework (S2 File) was used to line-by-line code the tran- scripts, and was developed from a number of sources: a previous systematic review [16]; the interview schedule; familiarisation with the interview transcripts; research team discussion; and the HRQoL domains of the EQ-5D-Y and HUI measures. Inductive codes which arose during the coding process were added to the coding framework. Codes were grouped into cat- egories of related codes, which were subsequently refined into higher order analytical themes giving a broader understanding of the coded transcripts and the relationship between catego- ries of codes.
Child and parent responses were analysed separately to account for their different but equally valid perspectives. Child age was also considered in the analyses, with separate analysis age groups defined as under 5s, 6 to 15 year olds and 16 to 18 year olds to represent stratifica- tion of NHS wheelchair provision. Type of wheelchair used was initially used to group data, but was later rejected due to consensus across the groupings.
Once coded, charts and maps were used to integrate the data to gain a richer understanding of the phenomena. This included integration of child and parent responses. Data were then used to build an understanding of how children with impaired mobility and their parents define mobility-related QoL, and the subsequent applicability of standard measures of HRQoL.
Theoretical position
We approached this research from an extra-welfarist, societal and social model of disability perspective, underpinned by principles of disability equality and utility theory.
The social model of disability postulates that people with impairments become disabled as a result of social oppression and discrimination. Disability is therefore defined as being a direct result of societal barriers to participation and independence imposed on people with impair- ments [48]. This theoretical position necessitated a broader view of disability and impairment in this study, looking beyond traditional medical definitions of health and disability. Thus, we focussed on a wide range of topics in the interviews and analyses.
Utility theory underpins popular methods of economic evaluation in healthcare, such as QALYs. Although utility cannot be derived directly, it is possible to rank different health states in order of societal preference. Therefore, the acceptable cost of a healthcare service or inter- vention is related to the marginal utility gains it provides.
Extra-welfarism is a normative approach to the analysis of health and healthcare, which includes outcomes such as individual utility, happiness, social interaction and pain. This approach is relevant to health as the development of public healthcare systems reflects the need to allocate resources fairly and efficiently within financial constraints. The QALY approach has a basis in extra-welfarism.
Utility theory and extra-welfarism underpin the QALY framework, therefore because we focused on the use of HRQoL data for economic evaluation purposes, these theories informed our understanding of HRQoL and the data we sought to collect.
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The study reported in this paper was underpinned by an overarching conceptual frame- work developed as part of a previous systematic review [16]. This conceptual framework maps areas for future research and service development to facilitate cost-effective wheelchair services for children with impaired mobility. One of the key areas identified for development was better outcome measurement, specifically relating to non-clinical needs, such as HRQoL.
Qualitative research reporting standards
To acknowledge the importance of explicit and comprehensive reporting of qualitative research, this paper follows the COREQ checklist for qualitative reporting standards [49]. As primary researcher, Dr Nathan Bray was solely responsible for conducting, coding and analys- ing all interviews. Wider discussion of the data within the research team was used to shape and test interpretations and to ensure internal validity. All participants were unknown to the research team prior to conducting the interviews.
Results
Participant quotes are presented as informative and clear representations of specific analytical themes. Irrelevant information has been replaced with ellipses [. . .] to facilitate ease of reading.
Table 1. Child demographic characteristics (child, parent and dyad samples).
Demographic characteristics Children N = 4 (%)
Parents N = 17 (%)
Dyads N = 7 (%)
Child gender
Female 1 (25) 6 (35.3) 3 (42.9)
Male 3 (75) 11 (64.7) 4 (57.1)
Child age
5 years or under 12 (70.6)
615 years 5 (29.4) 4 (57.1)
1618 years 4 (100) 3 (42.9)
Child ethnicity
White British 4 (100) 16 (94.1) 7 (100.0)
Other mixed background 1 (5.9)
Child diagnosis
Porencephaly 1 (5.9)
Cerebral Palsy 3 (75) 11 (64.7) 6 (85.7)
Muscular Dystrophy 1 (25) 2 (11.8)
Rett syndrome 1 (5.9)
Lissencephally 1 (5.9)
Chromosome deletion 1 (5.9)
Hemiplegia / stroke 1 (14.3)
Child Frequency of equipment use
A little of the time 1 (5.9)
Some of the time 4 (23.5)
Most of the time 3 (17.6) 1 (14.3)
All of the time 4 (100) 9 (52.9) 6 (85.7)
Child Type of equipment used
Powered 2 (11.8)
Manual 1 (25) 7 (41.2) 3 (42.9)
Manual and powered 3 (75) 8 (47.1) 4 (57.1)
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Repetitive speech and linguistic fillers (such as um) have been removed. Where there is more than one respondent presented in a single quote the following tags have been used for clarity: R: for researcher, C: for child, M: for mother and F: for father. The term child is used to refer to children with impaired mobility aged 18 or under who use a wheelchair. The term QoL is used to refer to mobility-related QoL; a specification of HRQoL. Participant ID num- bers are presented so that multiple quotes from the same individual can be identified.
Defining mobility-related QoL
In total, 15 categories were used by participants to define mobility-related QoL. The most com- monly identified code categories were independence, social interaction and activities/partici- pation. The 15 categories were synthesised to form 3 analytical themes, these were: participation and positive experiences; self-worth and feeling fulfilled; health and functioning. See Fig 1 for a breakdown of categories and analytical themes.
Participation and positive experiences. Being able to take part in positive and enjoyable experiences was an important aspect of defining QoL for children and parents across all age ranges. Furthermore, the categories of independence and activities/participation were the only common categories found across all sub-groups (i.e. 3 child age groups; children and parents).
Table 2. Parent sample demographic characteristics.
Demographic characteristics Parents N = 17 (%) Dyads N = 7 (%)
Parent gender
Female 15 (88.2) 7 (100.0)
Male 2 (11.8)
Parent age
2129 years 2 (11.8)
3039 years 11 (64.7) 1 (14.3)
4049 years 4 (23.5) 5 (71.4)
5059 years 1 (14.3)
Parent ethnicity
White British 16 (94.1) 7 (100.0)
White & Asian 1 (5.9)
Parent marital status
Married 11 (64.7) 7 (100.0)
Co-habiting 3 (17.6)
Single 2 (11.8)
Separated 1 (5.9)
Annual household Income
£500015,000 3 (17.6)
£16,000-£25,000 3 (17.6)
£26,000-£35,000 2 (11.8) 1 (14.3)
£36,000-£50,000 5 (29.4) 4 (57.1)
£51,000-£75,000 2 (11.8) 2 (28.6)
£75,000 or more 2 (11.8)
Parent employment status
Full-time 3 (17.6)
Part-time 6 (35.3) 3 (42.9)
Unemployed / stay at home parent 8 (47.1) 4 (57.1)
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A key aspect of participation for children and parents alike was being able to take part in activi- ties that are meaningful to the child, without restriction.
Mother of 4 year old male (P21): R: What does the term QoL mean to you in relation to [CHILDS NAME] and other children with disabilities?
M: Just that they get to have the opportunities and enjoyment of other children, really. And that what he is doing is meaningful to him.
Fig 1. Defining mobility-related QoL in childhood. A thematic summary and map of mobility-related QoL domains for children and young people.
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Adaptations and equipment such as wheelchairs played a vital role in removing barriers to participation and providing alternative ways for children to take part in activities. However, structural and environmental barriers, such as inadequate facilities or poor access for wheel- chairs, were seen as restrictive.
Mother of 10 year old female (P28): QoL is them being able to do anything they want to be able to do. And not being prevented from doing that by something stupid like not being able to access it because theres no ramp. Or no lift or something like that.
Closely related to activities and participation was social interaction. The ability to interact with friends and participate in social situations was of particular importance to older children. Parents did not place as great an emphasis on social interaction, and tended not to differentiate this from other forms of activities and participation. The importance of independence under- pins these key aspects of QoL. Children and parents described how wheelchairs and other adaptations positively impact independence by providing freedom of movement and the abil- ity for children to make their own decisions.
17 year old female (C29): Everywhere I went I was pushed around in this buggy when I went out. I was like 10 [years old] in a buggy, if you know what I mean. I felt left out quite a lot, theres just no independence just sitting in a buggy. I think its really good that little ones can have [PWCs] younger.
Older children discussed taking control of their own lives and being in charge of th
