Background
Foot impairments and disability persist in over 60% of children who have juvenile idiopathic arthritis (JIA) despite recent improvements in its medical management [
1,
2]. The management of foot problems in JIA is complex and involves combinations of medical and non-medical therapies such as intra-articular corticosteroid injections, foot orthoses and exercise regimens [
2‐
5]. Regular visits to out-patients clinics are often necessary and the burden of seeking care may be detrimental to routine family life [
6]. Moreover, paediatric patient adherence to rehabilitative strategies is often poor and non-compliance may limit the potential for benefits in outcomes following therapy [
7,
8]. As such children with JIA may respond poorly to intervention resulting in sustained physical impairment, which may contribute negatively to the economic impact of JIA [
9,
10].
Health care priorities and the preferences of health care providers’ have been found to differ from those of their patients, particularly patients with inflammatory arthritis [
11]. An increased awareness of patients’ and parents’ care preferences is desirable from a clinical perspective as such information may be utilised to optimise care delivery [
12,
13]. Qualitative perceptions of foot care in JIA have been explored recently and several areas for service improvement have been identified [
14]. However a limitation of qualitative research is that it does not permit the ranking of preferences to provide information regarding the importance of different aspects of care.
Parents’ preferences for drug treatments and health outcomes in JIA have recently been explored, using a technique known as a discrete choice experiment (DCE) [
15]. This study found that parents demonstrated stronger preferences for treatments that reduced pain and improved daily functioning, regardless of other considerations such as associated side effects [
15]. A DCE is a quantitative technique for eliciting individual’s preferences for care [
16]. A DCE questionnaire is comprised of choice sets of hypothetical scenarios that are presented to study participants. Each scenario describes different levels of the attributes that characterise the intervention under evaluation [
17]. The participants’ preferences are elicited by asking them to state which scenario they prefer. DCEs are advantageous by several means; they are useful in the context of clinical trials, as they permit the gathering of rich preference information concerning interventions that are exploratory/experimental in nature [
18,
19]; they result in trade-off decisions between health-related attributes which mimic real-life decision-making situations [
16,
20]; and they can be used within the framework of cost benefit analyses (CBA) to estimate the value of individuals’ care preferences [
21,
22]. When cost is also considered as an attribute alongside health-related outcomes, it is possible to conduct an indirect calculation of respondents’ willingness-to-pay (WTP) for health care [
23,
24]. Willingness-to-pay can be formally defined as the maximum amount of money that an individual is prepared to part with in order to receive a particular service [
25]. The WTP concept has been applied previously in JIA to assess health care preferences of families of children with the disease using a series of ‘bidding game’ questions [
26], but it may also be elicited through face to face interviews or self-administered questionnaires.
To understand parents’ preferences, two elicitation techniques were employed. A DCE provided insight as to the relative importance of various attributes of foot care. Additionally willingness-to-pay (WTP) values were elicited to understand the monetary value parents place on foot care for children/adolescents with JIA.
Discussion
This study resulted reports on the development and design of a DCE and stated preference WTP questionnaire used to elicit parental preferences for foot care for children with JIA. According to the British Society for Paediatric and Adolescent Rheumatology (BSPAR) and Arthritis and Musculoskeletal Alliance (ARMA) standards of care for JIA guidelines, all children and adolescents with JIA should have access to foot care [
39,
40]. At present very little is known about the provision of foot care in JIA [
2,
14], and there is little evidence on parents’ views and opinions of foot care, particularly from those who have had no experience of foot care services. As such this study adds rich and robust information regarding preferences for foot care in JIA which could be utilised to improve foot care services.
The results suggest that parent respondents appeared to prefer improvements in health outcomes over non-health outcomes and podiatry service process attributes. This is a common but not an exclusive finding in DCE research. A recent DCE found that parents of children with JIA demonstrated strong preferences for interventions that reduced pain and improved function [
15]. In contrast, adult rheumatology outpatients ranked non-health attributes as more important relative to pain levels [
41]. The results from this study may represent parents’ desires for their children to have more normal lives, but further research is required to substantiate this claim.
Maximal improvements in the ADL attribute appeared to be the most important attribute to parents. Arguably this finding is somewhat surprising, as it appears to have a greater influence over parents’ choices relative to improvements in pain relief. Pain relief has been cited an important aspect of care by parents, patients, paediatric rheumatologists and allied health professionals in previous studies [
14,
15]. Overall, maximal improvements in the ADL attribute, together with ‘pain’, ‘mobility’ and ‘ability to wear desired footwear’ attributes were considered to be most important to the parent respondents. However, it is possible that children’s experiences of JIA may lead to different preferences for care that are centred on their sense of self and social identity [
42]. For example, in this study parents appeared to prefer the options for improvements in their child’s health, however qualitative research suggests children with JIA may not want to be labelled as sick or disabled and therefore may have entirely different preferences for their own care [
42].
The parental preference data derived from this DCE may be useful for informing aspects of service provision for children who have JIA related foot problems. Previous research suggests paediatric rheumatologists and health professionals require more information about which foot symptoms are in need of urgent attention [
14]. Parental preferences for the key outcomes identified in this study could be incorporated into a new patient-reported outcome measure designed to inform urgency for referral to foot care services. Alternatively, the use of an existing tool known as the Juvenile Arthritis Foot Disability Index [
43] which includes items related to these key outcomes, could be re-designed to incorporate foot disability severity thresholds and guide referrals for foot care.
A lack of suitable footwear choices for children with JIA-related foot disease has been previously identified as problematic [
14]. Parents appeared to rank the ability of their child to wear desired footwear as important, confirming previous findings. In contrast to a growing body of research in adult RA, [
44,
45] the impact of limited footwear choices as a result of disease-related foot problems have not been investigated in JIA. This is surprising as foot deformities such as valgus hindfoot and clawed lesser toes appear to be common [
2,
46,
47].
Of the process attributes, ‘route to care’ involving an appointment with the paediatric rheumatologist, podiatrist and physiotherapist in the same visit was considered to some importance, and was more important than waiting time and cost. This is a novel finding as it demonstrates that parents may gain utility from the prospect of their child receiving multi-disciplinary foot care, as opposed to a separate doctor’s referral for separate foot care. However, this could be the result of the Hawthorne effect where respondents have modified their decision making process as a response to being enrolled in the main ‘open label’ RCT of multidisciplinary foot care [
23,
48].
Unlike the majority of DCEs, the cost attribute did not reach statistical significance in the regression analysis. This implies that parents’ preferences were not influenced by having to pay more. The stated preference (payment scale) WTP question supports this, on average parents were willing to pay £224, with six parents stating that they would pay anything to improve their child’s health outcomes. It is important to acknowledge that in a health care system where care is free at the point of access (as is the case in the NHS); it is difficult to obtain accurate information to inform the levels of cost in a DCE. It is possible that the values of £80, £150 and £220 were too low. In addition, household income data was not available and as such WTP figures were not expressed as a percentage of income, which would have been a more useful representation of parents’ WTP. Future research perhaps should seek to replicate this DCE with higher values as guided by the stated preference WTP results, or preferably as a percentage of household income. Only then would it be possible to ascertain if a parent views their child’s health as ‘priceless’.
When completing DCEs, respondents are required to process large amounts of information resulting in significant cognitive burden [
49]. As such, respondents may make attempts to reduce their cognitive burden through lexicographic and heuristic strategies [
26,
50,
51]. Lexicographic preferences are where a respondent ranks attributes in order of importance and bases their decision on the highest priority attributes [
49]. While heuristics are where respondents employ simple ‘rules of thumb’ to reduce the cognitive burden, such as limiting their responses to trade-offs between one or two attributes per scenario [
50,
51]. Furthermore, the sequential ordering of attributes in the DCE scenarios can have an effect on the relative utility weights associated with those attributes [
52]. The effects of sequential ordering on utility weights were not formally explored in this study; however it is interesting to note that the β coefficients of the first three attributes listed in the DCE scenarios have the greatest magnitude. Whereas, ‘cost’ was the lowermost attribute in the DCE scenarios and had the smallest β coefficient magnitude.
The sample size of the study must also be considered when interpreting its results. The sample size was dictated by the number of participants enrolled in the main RCT [
27]. It should also be noted this DCE was performed in a group of parents whose children were enrolled in an exploratory RCT of multidisciplinary foot care [
27] and therefore there may be a threat to the external validity of its findings due to cross-purpose, convenience and Hawthorne effects. Nevertheless, the DCE was administered at baseline prior to exposure to the foot care intervention, and the inclusion criteria of the parent study [
27] (see Participants and Setting) appear directly relevant to the present study which aimed to elicit foot care preference information of parents of children with JIA who have foot problems. Of those parents who participated, only 42 fully completed the DCE questionnaire. According to the literature previous DCEs have recruited a minimum of 40 respondents to successfully establish sufficient models [
53]. However with the inclusion of the ‘neither’ option and the high frequency of non-responses, it is likely that a larger sample size may have improved both the richness and robustness of the results. It should be noted that the sample size was driven by the RCT sample which, while not directly relevant to the statistical modelling in this study was appropriately powered for the trial endpoint.
An unresolved issue in health economics is the application of WTP elicitation methods where respondents receive care which is free at the point of contact in a publicly funded healthcare system such as the NHS in the UK. As such some respondents may interpret the WTP value as the cost incurred by the health service to deliver that service. Alternatively respondents may interpret the cost attribute as one that can be ignored as cost is not incurred by them directly [
21]. It is possible that either of these points may have contributed to the non-significance of the cost attribute in this study. Lastly, it should be noted that household income data was not measured as part of this study so as not to overburden respondents who were required to complete many questionnaires during the main RCT. This restricted our ability to identify whether or not income influenced respondents choice, particularly concerning cost. As such, the results relating to cost could be potentially misleading, and future DCEs including a cost attribute should include cost as an appropriately determined percentage of household income.
Competing interests
The authors declare that they have no competing interest.
Authors’ contributions
GJH and PKL conceived and executed the study protocol. All co-authors contributed to the final design of the study protocol. GJH was responsible for the collection of study data. GJH and PKL interpreted the findings with assistance from all co-authors. GJH drafted the manuscript and the final version was read, reviewed and approved by all co-authors.