Patient and observer reported outcome measures to evaluate health-related quality of life in inherited metabolic diseases: a scoping review

Abstract

BackgroundHealth-related Quality of Life (HrQoL) is a multidimensional measure, which has gained clinical and social relevance. Implementation of a patient-centred approach to both clinical research and care settings, has increased the recognition of patient and/or observer reported outcome measures (PROMs or ObsROMs) as informative and reliable tools for HrQoL assessment. Inherited Metabolic Diseases (IMDs) are a group of heterogeneous conditions with phenotypes ranging from mild to severe and mostly lacking effective therapies. Consequently, HrQoL evaluation is particularly relevant.ObjectivesWe aimed to: (1) identify patient and/or caregiver-reported HrQoL instruments used among IMDs; (2) identify the main results of the application of each HrQoL tool and (3) evaluate the main limitations of HrQoL instruments and study design/methodology in IMDs.MethodsA scoping review was conducted using methods outlined by Arksey and O’Malley. Additionally, we critically analysed each article to identify the HrQoL study drawbacks.ResultsOf the 1954 studies identified, 131 addressed HrQoL of IMDs patients using PROMs and/or ObsROMs, both in observational or interventional studies. In total, we identified 32 HrQoL instruments destined to self- or proxy-completion; only 2% were disease-specific. Multiple tools (both generic and disease-specific) proved to be responsive to changes in HrQoL; the SF-36 and PedsQL questionnaires were the most frequently used in the adult and pediatric populations, respectively. Furthermore, proxy data often demonstrated to be a reliable approach complementing self-reported HrQoL scores. Nevertheless, numerous limitations were identified especially due to the rarity of these conditions.ConclusionsHrQoL is still not frequently assessed in IMDs. However, our results show successful examples of the use of patient-reported HrQoL instruments in this field. The importance of HrQoL measurement for clinical research and therapy development, incites to further research in HrQoL PROMs’ and ObsROMs’ creation and validation in IMDs.Electronic supplementary materialThe online version of this article (10.1186/s13023-018-0953-9) contains supplementary material, which is available to authorized users.

New Insights into Immunological Involvement in Congenital Disorders of Glycosylation (CDG) from a People-Centric Approach

“…Health-related QoL has been gaining research momentum and clinical importance, also in inherited metabolic diseases [46]. This is a subjective measure which only the people living with (or caring for patients with) the disease can provide.…”

Experiences of patients with Poland syndrome of diagnosis and care in Italy: a pilot survey

“…Furthermore, given the heterogeneity of the patients’ age, questionnaires were filled in by caregivers in case of minors, while adult patients filled in the questionnaire autonomously. Differences between self- and proxy-completed responses on health status surveys are well described in the literature [36, 37]. For example, some studies have reported that parents tend to assign a lower score on health-related quality of life questions regarding their children with a chronic health condition [38–40].…”

The Use of Patient-Reported Outcome Measures in Rare Diseases and Implications for Health Technology Assessment

“…Instruments are often not fit for purpose, and HTA evaluators are often not convinced a PROM is measuring what it is claimed to be measuring [29,31] Prior discussion with the relevant evaluating agencies can help to ensure a PROM is compatible with their standards [5,22,32] Probably feasible: This requires stakeholder willingness for planning and time commitment but has the potential to save a substantial amount of time later in the process Need for early and, if possible, iterative engagement between RDT developers and HTA evaluators Conventional methods are not always suitable for psychometric analysis in RDs because they require large samples and high-quality data [13,33,35] RD populations can be combined with populations with similar disease presentations to increase sample size [14] Feasible: Combining populations with similar disease characteristics would require guidelines and best practices, but, if done properly, provides a promising solution to overcoming the limited RD sample size Use of expert panel review to determine face validity/generalizability; hybrid conceptelicitation or cognitive interviews or linking items to international classification systems to determine content validity [11,36] Probably feasible: Qualitative data can be a good approach to ensuring validity without relying on large sample sizes but would require time and resource investment Need for recognition of the importance of, and willingness to consider, other forms of evidence in informing HRQoL impact…”

“…• Data are usually collected from small patient populations [12], which may result in inaccurate aggregate results. • Conditions and presentations can be heterogeneous, which make it difficult to capture meaningful and generalizable outcomes [3,[12][13][14][15]]. • Information and understanding regarding disease progression and natural history is lacking, which makes it difficult to know which PROMs to use or how to develop new PROMs [12,13,16,17].…”