Health‐related quality of life in children with neurodevelopmental disabilities: assessment of a scoping review

Abstract

When the current body of research in a clinical area is too limited to support a high-quality systematic review, the newly available scoping review has become the appropriate tool in our evidence-based medicine (EBM) toolkit. The same systematic review standards and robust scientific review procedures and supports, including exemplar tools, are now available for scoping reviews. This paper on the nature, extent, and challenges of instruments being used to measure quality of life in children with neurodevelopmental disabilities, is a perfect fit with the scoping review type, and provides an excellent methodological example of its use and value in EBM. But first, what differentiates the scoping review from the systematic review? The purpose of a systematic review is to identify, appraise, and synthesize all the empirical evidence that meets prespecified eligibility criteria to answer a narrow research question, yielding the most reliable findings to inform decision-making about healthcare. It depends on a mature and relatively large body of evidence with studies that produced high-quality levels of evidence about a targeted intervention and outcome(s) in a specific type of study participant. A good example of a systematic review is the paper by Booth et al. The purpose of the scoping review, on the other hand, is to answer a broad question from an emerging or otherwise limited body of evidence when it is still unclear what more specific questions can be valuably addressed through a systematic review. It scopes out, aggregates, and maps all available evidence about a healthcare topic regardless of its quality and type. It describes, at least minimally, the quality of the evidence to identify gaps in the evidence and highlights what research is needed to eventually inform practice. As a tool of evidence reconnaissance, scoping reviews can also be used to map evidence in relation to time, location, or source of evidence, to clarify key concepts and challenges, and to examine policies. In their scoping review of assessment of health-rated quality of life (HRQoL), Lamsal et al. have led us through a topic that affects the practice of all healthcare professionals, but about which few have knowledge. It gives insight into the complex and somewhat technical topic of economic evaluations that use cost-utility analysis expressed in quality adjusted life years (QUALs). This is a metric that combines length and quality of life into a single outcome. HRQoL instruments are used to estimate the quality component and this review identifies the most commonly used HRQoL instruments. Health organizations in the UK, Canada, and Australia increasingly require health effects of an intervention to be captured using the QUAL. Despite the depth and breadth of this scoping review, the myriad of diverse data is so well organized and thoroughly presented that one can readily follow the full nature and extent of the issues and problems of this research area. It explores the challenges and methodological concerns of using these instruments developed for adults to evaluate childhood health states. It identifies debates about whose preferences should be used (i.e. the child, parent/caregiver/proxy respondent). It addresses the barrier of the absence of formal indexing in databases and inconsistent reporting of studies that makes it difficult to find relevant evidence. It describes the lack of psychometric data about the validity and reliability of these instruments and the generally low-quality appraisal of the studies in which they were used. It includes discussion of the need for country-specific preference weighting to reflect the relative value societies place on different health states. The authors conclusions rightly suggest caution for the current state of the evidence to be used to inform policy and care decisions due to the potential for measurement error. At the same time, they have highlighted the pressing issues to be resolved.