Preference-based measures of health-related quality of life in congenital mobility impairment: a systematic review of validity and responsiveness

Abstract

Introduction: Mobility impairment is the leading cause of disability in the UK. Individuals with congenital mobility impairments have unique experiences of health, quality of life and adaptation. Preference-based outcomes measures are often used to help inform decisions about healthcare funding and prioritisation, however the applicability and accuracy of these measures in the context of congenital mobility impairment is unclear. Inaccurate outcome measures could potentially affect the care provided to these patient groups. The aim of this systematic review was to examine the performance of preference-based outcome measures for the measurement of utility values in various forms of congenital mobility impairment. Methods: Ten databases were searched, including Science Direct, CINAHL and PubMed. Screening of reference lists and hand-searching were also undertaken. Descriptive and narrative syntheses were conducted to combine and analyse the various findings. Results were grouped by condition. Outcome measure performance indicators were adapted from COSMIN guidance and were grouped into three broad categories: validity, responsiveness and reliability. Screening, data extraction and quality appraisal were carried out by two independent reviewers. Results: A total of 31 studies were considered eligible for inclusion in the systematic review. The vast majority of studies related to either cerebral palsy, spina bifida or childhood hydrocephalus. Other relevant conditions included muscular dystrophy, spinal muscular atrophy and congenital clubfoot. The most commonly used preference-based outcome measure was the HUI3. Reporting of performance properties predominantly centred around construct validity, through known group analyses and assessment of convergent validity between comparable measures and different types of respondents. A small number of studies assessed responsiveness, but assessment of reliability was not reported. Increased clinical severity appears to be associated with decreased utility outcomes in congenital mobility impairment, particularly in terms of gross motor function in cerebral palsy and lesion level in spina bifida. However, preference-based measures exhibit limited correlation with various other condition-specific and clinically relevant outcome measures.(Continued on next page) Conclusion: Preference-based measures exhibit important issues and discrepancies relating to validity and responsiveness in the context of congenital mobility impairment, thus care must be taken when utilising these measures in conditions associated with congenital mobility impairments.

Assessing the relative importance of key quality of life dimensions for people with and without a disability: an empirical ranking comparison study

“…However, the authors concluded that there is not a universally accepted ‘gold-standard’ for measuring the quality of life of adults with an intellectual disability [ 25 ]. A recent systematic review by Bray et al [ 26 ] explored which instruments are commonly used to assess the quality of life of individuals with congenital mobility disabilities. The authors also concluded that current quality of life instruments are insufficient to capture the quality of life dimensions of most importance to people with a disability [ 26 ].…”

“…A recent systematic review by Bray et al [ 26 ] explored which instruments are commonly used to assess the quality of life of individuals with congenital mobility disabilities. The authors also concluded that current quality of life instruments are insufficient to capture the quality of life dimensions of most importance to people with a disability [ 26 ]. It is important to note, however, that both systematic reviews did not specifically review preference-based quality of life measures and neither included the ASCOT measure; which was designed for assessing the social care-related quality of life of people with support needs related to long-term health conditions or disability.…”

“…The empirical ranking exercise has drawn out the differences in relative importance rankings for alternative quality of life dimensions between those with and without disability. It may initially be surprising that the relative importance rankings of quality of life dimensions for people with a disability and their carers were broadly equivalent given the extensive body of literature that indicates that proxy reported quality of life can often differ markedly from self-reported quality of life [ 26 – 29 ]. However, this study was different in that it focused on the relative weights attached to different quality of life dimensions by self and proxy sub-groups, not on the actual quality of life of a person with a disability.…”

Preference-based measurement of mobility-related quality of life: developing the MobQoL-7D health state classification system

“…Although there are existing outcome measures related to movement, occupational performance and assistive technology [33][34][35][36][37][38][39], none of these instruments explicitly cover the concept of mobility-related quality of life. Our previous research identified the unique ways in which individuals with mobility impairments define and experience health-related quality of life [23,25], and also the issues with using generic preference-based measures in populations with impaired mobility [12,20]. The MobQoL-7D was therefore developed to be a novel condition-specific preferencebased measure for patient groups with impaired mobility.…”

“…The use of generic preference-based measures, such as the EQ-5D and HUI systems, has been relatively limited in the context of mobility impairment, particularly congenital mobility impairment [12]. In conditions such as cerebral palsy and spina bifida, increased clinical severity is associated with decreased utility.…”