Systematic Review of Conceptual, Age, Measurement and Valuation Considerations for Generic Multidimensional Childhood Patient-Reported Outcome Measures

Comparing Generic Paediatric Health-Related Quality-of-Life Instruments: A Dimensionality Assessment Using Factor Analysis

BACKGROUND

Widely used generic instruments to measure paediatric health-related quality of life (HRQoL) include the EQ-5D-Y-5L, Child Health Utility 9 Dimension (CHU-9D), Paediatric Quality of Life Inventory (PedsQL) and Health Utilities Index (HUI). There are similarities and differences in the content of these instruments, but there is little empirical evidence on how the items they contain relate to each other, and to an overarching model of HRQoL derived from their content.

OBJECTIVE

This study aimed to explore the dimensionality of the instruments using exploratory factor analysis (EFA).

METHODS

Data from the Australian Paediatric Multi-Instrument Comparison (P-MIC) Study were used. EQ-5D-Y-5L, CHU-9D, PedsQL and HUI data were collected via proxy or child self-report data. EFA was used to investigate the underlying domain structure and measurement relationship. Items from the four instruments were pooled and domain models were identified for self- and proxy-reported data. The number of factors was determined based on eigenvalues greater than 1. A correlation cut-off of 0.32 was used to determine item loading on a given factor, with cross-loading also considered. Oblique rotation was used.

RESULTS

Results suggest a six-factor structure for the proxy-reported data, including emotional functioning, pain, daily activities, physical functioning, school functioning, and senses, while the self-report data revealed a similar seven-factor structure, with social functioning emerging as an additional factor.

CONCLUSION

We provide evidence of differences and similarities between paediatric HRQoL instruments and the aspects of health being measured by these instruments. The results identified slight differences between self- and proxy-reported data in the relationships among items within the resulting domains.

Health-related quality of life and subjective well-being among children aged 9-12 years in Shandong Province, China

PURPOSE

To investigate the health-related quality of life (HRQoL) and subjective well-being (SWB) of children aged 9-12 years in eastern China, and examine concordance within child self-reported and parent proxy-assessed.

METHODS

Data was collected from 9 to 12 years old children (including their parents) in Shandong Province in 2018. Participants self-completed a hard-copy questionnaire including Child Health Utility 9D (CHU9D), Pediatric Quality of Life Inventory (PedsQL)™ 4.0 Short Form 15 Generic Core Scales (hereafter the PedsQL™), Student's Life Satisfaction Scale (SLSS), as well as information on socio-demographic characteristics and self-report health status. Spearman's correlation coefficients and the difference between sub-groups were conducted to assess and compare the agreement on HRQoL and SWB instruments. Exploratory factor analysis (EFA) was used to ascertain the number of unique underlying latent factors that were associated with the items covered by the two generic HRQoL and the SWB instruments. The concordance of child self-reported and parent proxy-assessed was analyzed using weighted kappa coefficient and Bland-Altman plots.

RESULTS

A total of 810 children and 810 parents were invited to participate in the survey. A valid sample of 799 (98.6%) children and 643 (79.4%) parents completed the questionnaire. The child self-reported mean scores were CHU9D = 0.87, PedsQL™ = 83.47, and SLSS = 30.90, respectively. The parent proxy-assessed mean scores were PedsQL™ = 68.61 and SLSS = 31.23, respectively. The child self-reported PedsQL™ was moderately correlated with the CHU9D (r = 0.52). There was a weak correlation between CHU9D and SLSS (r = 0.27). The EFA result found 3 factors whilst seven SLSS items grouped into a standalone factor (factor 3), and the nine dimensions of CHU9D shared two common factors with the PedsQL™ (factor 1 and factor 2). A low level of concordance was observed across all comparisons and in all domains (weighted kappa < 0.20) between parents and their children. Furthermore, a high level of discordance was observed between child self-reported and father proxy-assessed.

CONCLUSIONS

CHU9D and PedsQL™ instruments have a higher agreement in measuring the HRQoL in children. CHU9D/PedsQL™ and SLSS instruments showed a low agreement and EFA result suggested that measuring SWB in children potentially may provide further information, which might be overlooked by using HRQoL instruments exclusively. Concordance of child self-reported and parent proxy-assessed was poor. Overall, mother-child concordance was higher than father-child concordance.

Understanding Canadian stakeholders' views on measuring and valuing health for children and adolescents: a qualitative study

OBJECTIVE

Valuing child health is critical to assessing the value of healthcare interventions for children. However, there remain important methodological and normative issues. This qualitative study aimed to understand the views of Canadian stakeholders on these issues.

METHODS

Stakeholders from health technology assessment (HTA) agencies, pharmaceutical industry representatives, healthcare providers, and academic researchers/scholars were invited to attend an online interview. Semi-structured interviews were designed to focus on: (1) comparing the 3-level and 5-level versions of the EQ-5D-Y; (2) source of preferences for valuation (adults vs. children); (3) perspective of valuation tasks; and (4) methods for valuation (discrete choice experiment [DCE] and its variants versus time trade-off [TTO]). Participants were probed to consider HTA guidelines, cognitive capacity, and potential ethical concerns. All interviews were recorded and transcribed verbatim. Framework analysis with the incidence density method was used to analyze the data.

RESULTS

Fifteen interviews were conducted between May and September 2022. 66.7% (N = 10) of participants had experience with economic evaluations, and 86.7% (N = 13) were parents. Eleven participants preferred the EQ-5D-Y-5L. 12 participants suggested that adolescents should be directly involved in child health valuation from their own perspective. The participants were split on the ethical concerns. Eight participants did not think that there was ethical concern. 11 participants preferred DCE to TTO. Among the DCE variants, 6 participants preferred the DCE with duration to the DCE with death.

CONCLUSIONS

Most Canadian stakeholders supported eliciting the preferences of adolescents directly from their own perspective for child health valuation. DCE was preferred if adolescents are directly involved.

Identifying Relevant Concepts for the Development of a Communicative Participation Item Bank for Children and Adolescents: A Systematic Review of Existing Instruments

PURPOSE

This study aims to systematically identify items that measure communicative participation from measurement instruments that measure (aspects of) communication and/or participation in children and adolescents (5-18 years old) with communication disorders, for developing an item bank.

METHOD

A systematic literature search was performed in MEDLINE and Embase to search for patient-reported outcome measures (PROMs) or parent reports measuring aspects of communication and/or participation in children and adolescents. The individual items of the included measurement instruments were reviewed on whether they measure communicative participation. The items were then classified into one of the International Classification of Functioning, Disability and Health (ICF) for Children and Youth (World Health Organization, 2007) domains of activities and participation.

RESULTS

A total of 29 instruments were found, nine PROMs and 20 parent reports. One hundred forty-five items were identified that measure communicative participation. From these 145 items, 74 were retrieved from PROMs (51%), and 71 were retrieved from parent reports (49%). The majority of items were classified in ICF Domain 7, interpersonal interactions and relationships (73.8%), followed by Domain 8, major life areas (13.8%), and Domain 9, community, social, and civic life (8.3%). Only a few items were found in Domains 5 and 6, and none was found in Domains 1, 2, and 4.

CONCLUSIONS

We identified 145 items potentially useful for developing an item bank addressing communicative participation in children and adolescents with communication disorders. However, item development in collaboration with the target population is needed to ensure that these items fully reflect the construct.

The RETRIEVE Checklist for Studies Reporting the Elicitation of Stated Preferences for Child Health-Related Quality of Life

BACKGROUND

Recent systematic reviews show varying methods for eliciting, modelling, and reporting preference-based values for child health-related quality-of-life (HRQoL) outcomes, thus producing value sets with different characteristics. Reporting in many of the reviewed studies was found to be incomplete and inconsistent, making them difficult to assess. Checklists can help to improve standards of reporting; however, existing checklists do not address methodological issues for valuing child HRQoL. Existing checklists also focus on reporting methods and processes used in developing HRQoL values, with less focus on reporting of the values' key characteristics and properties. We aimed to develop a checklist for studies generating values for child HRQoL, including for disease-specific states and value sets for generic child HRQoL instruments.

DEVELOPMENT

A conceptual model provided a structure for grouping items into five modules. Potential items were sourced from an adult HRQoL checklist review, with additional items specific to children developed using recent reviews. Checklist items were reduced by eliminating duplication and overlap, then refined for relevance and clarity via an iterative process. Long and short checklist versions were produced for different user needs. The resulting long RETRIEVE contains 83 items, with modules for reporting methods (A-D) and characteristics of values (E), for researchers planning and reporting child health valuation studies. The short RETRIEVE contains 14 items for decision makers or researchers choosing value sets.

CONCLUSION

Applying the RETRIEVE checklists to relevant studies suggests feasibility. RETRIEVE has the potential to improve completeness in the reporting of preference-based values for child HRQOL outcomes and to improve assessment of preference-based value sets.

Assessment of health state utilities associated with adult and pediatric acid sphingomyelinase deficiency (ASMD)

INTRODUCTION

Acid sphingomyelinase deficiency (ASMD) type B is a rare genetic disorder leading to enlargement of the spleen and liver, pulmonary dysfunction, and other symptoms. Cost-utility analyses are often conducted to quantify the value of new treatments, and these analyses require health state utilities. Therefore, the purpose of this study was to estimate utilities associated with varying levels of severity of adult and pediatric ASMD type B.

METHODS

Seven adult and seven child health state vignettes describing ASMD were developed based on published literature, clinical trial results, and interviews with clinicians, patients with ASMD, and parents of children with ASMD. The health states were valued in time trade-off interviews with adult general population respondents in the UK.

RESULTS

Interviews were completed with 202 participants (50.0% female; mean age = 41.3 years). The health state representing ASMD without impairment had the highest mean utility for both the adult and child health states (0.92/0.94), and severe ASMD had the lowest mean utility (0.33/0.45). Every child health state had a significantly greater utility than the corresponding adult health state. Differences between adult/child paired states ranged from 0.02 to 0.13. Subgroup analyses explored the impact of parenting status on valuation of child health states.

DISCUSSION

Greater severity of ASMD was associated with lower mean utility. Results have implications for valuation of pediatric health states. The resulting utilities may be useful in cost-utility modeling estimating the value of treatment for ASMD.

Comparing the Psychometric Performance of Generic Paediatric Health-Related Quality of Life Instruments in Children and Adolescents with ADHD, Anxiety and/or Depression

OBJECTIVE

The aim of this study was to examine the validity, reliability and responsiveness of common generic paediatric health-related quality of life (HRQoL) instruments in children and adolescents with mental health challenges.

METHODS

Participants were a subset of the Australian Paediatric Multi-Instrument Comparison (P-MIC) study and comprised 1013 children aged 4-18 years with attention-deficit/hyperactivity disorder (ADHD) (n = 533), or anxiety and/or depression (n = 480). Participants completed an online survey including a range of generic paediatric HRQoL instruments (PedsQL, EQ-5D-Y-3L, EQ-5D-Y-5L, CHU9D) and mental health symptom measures (SDQ, SWAN, RCADS-25). A subset of participants also completed the HUI3 and AQoL-6D. The psychometric performance of each HRQoL instrument was assessed regarding acceptability/feasibility; floor/ceiling effects; convergent validity; known-group validity; responsiveness and test-retest reliability.

RESULTS

The PedsQL, CHU9D, EQ-5D-Y-3L and EQ-5D-Y-5L showed similarly good performance for acceptability/feasibility, known-group validity and convergent validity. The CHU9D and PedsQL showed no floor or ceiling effects and fair-good test-retest reliability. Test-retest reliability was lower for the EQ-5D-Y-3L and EQ-5D-Y-5L. The EQ-5D-Y-3L showed the highest ceiling effects, but was the top performing instrument alongside the CHU9D on responsiveness to improvements in health status, followed by the PedsQL. The AQoL-6D and HUI3 showed good acceptability/feasibility, no floor or ceiling effects, and good convergent validity, yet poorer performance on known-group validity. Responsiveness and test-retest reliability were not able to be assessed for these two instruments. In subgroup analyses, performance was similar for all instruments for acceptability/feasibility, known-group and convergent validity, however, relative strengths and weaknesses for each instrument were noted for ceiling effects, responsiveness and test-retest reliability. In sensitivity analyses using utility scores, performance regarding known-group and convergent validity worsened slightly for the EQ-5D-Y-3L and CHU9D, though improved slightly for the HUI3 and AQoL-6D.

CONCLUSIONS

While each instrument showed strong performance in some areas, careful consideration of the choice of instrument is advised, as this may differ dependent on the intended use of the instrument, and the age, gender and type of mental health condition of the population in which the instrument is being used.

TRIAL REGISTRATION

ANZCTR-ACTRN12621000657820.

Mapping the 12-item World Health Organization disability assessment schedule 2.0 (WHODAS 2.0) onto the assessment of quality of life (AQoL)-4D utilities

PURPOSE

The World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) is a widely used disability-specific outcome measure. This study develops mapping algorithms to estimate Assessment of Quality of Life (AQoL)-4D utilities based on the WHODAS 2.0 responses to facilitate economic evaluation.

METHODS

The study sample comprises people with disability or long-term conditions (n = 3376) from the 2007 Australian National Survey of Mental Health and Wellbeing. Traditional regression techniques (i.e., Ordinary Least Square regression, Robust MM regression, Generalised Linear Model and Betamix Regression) and machine learning techniques (i.e., Lasso regression, Boosted regression, Supported vector regression) were used. Five-fold internal cross-validation was performed. Model performance was assessed using a series of goodness-of-fit measures.

RESULTS

The robust MM estimator produced the preferred mapping algorithm for the overall sample with the smallest mean absolute error in cross-validation (MAE = 0.1325). Different methods performed differently for different disability subgroups, with the subgroup with profound or severe restrictions having the highest MAE across all methods and models.

CONCLUSION

The developed mapping algorithm enables cost-utility analyses of interventions for people with disability where the WHODAS 2.0 has been collected. Mapping algorithms developed from different methods should be considered in sensitivity analyses in economic evaluations.

Psychometric Properties of Child Health Utility 9D (CHU9D) Proxy Version Administered to Parents and Caregivers of Children Aged 2-4 Years Compared with Pediatric Quality of Life Inventory™ (PedsQL)

OBJECTIVE

This study examines the psychometric properties of the Child Health Utility 9D (CHU9D) proxy version administered to parents/caregivers of 2-4-year-old Australian children compared with Pediatric Quality of Life Inventory™ version 4.0 (PedsQL).

METHODS

Data collected in 2021/2022 from parents/caregivers of 2-4-year-olds from the Australian pediatric multi-instrument comparison study were used. Feasibility, ceiling/floor effects, test-retest reliability, convergent validity, known-group validity, and responsiveness were assessed.

RESULTS

A total of 842 caregivers completed the survey at baseline, with 513 completing the follow-up survey. The CHU9D did not demonstrate ceiling effects in the sample with special health care needs, with only 6% of respondents reporting best levels for all nine dimensions. CHU9D correlated with PedsQL moderately-to-strongly between comparable items (correlation coefficients 0.34-0.70). CHU9D was able to differentiate between groups with known health differences with moderate-to-large effect sizes (Cohen's d 0.58-2.03). Moderate test-retest reliability was found for CHU9D in those reporting no health change at a 2-day follow-up (ICC 0.52). A standard response mean (SRM) of 0.25-0.44 was found for children with changes in general health and a SRM of 0.72-0.82 for children who reported worsened health when developing new illnesses, indicating small-to-large responsiveness according to different definitions of health changes. Compared with PedsQL, CHU9D had similar known-group validity and responsiveness and slightly poorer test-retest reliability.

CONCLUSION

The CHU9D was found to be valid and reliable to measure health-related quality-of-life in children aged 2-4 years, although with relatively low test-retest reliability in some dimensions. Further development and validation work is warranted.

Fighting to Breathe and Fighting for Health-Related Quality of Life: Measuring the Impact of Being Dependent on Technology for Breathing on the Child and Their Caregiver

BACKGROUND AND OBJECTIVE

Medical advancement has enabled children to survive congenital airway anomalies, rare diseases and critical illnesses with medical technology including tracheostomies and long-term ventilation to support breathing. This study aimed to assess (1) the validity of the EQ-TIPS and EQ-5D-Y-3L in children dependent on technology and (2) the impact of caring for these children on the EQ-5D-5L and CarerQoL.

METHODS

Caregivers of children aged 1 month to 18 years completed the EQ-TIPS or EQ-5D-Y-3L, Pediatric Quality of Life Inventory (PedsQL) and Paediatric Tracheostomy Health Status Instrument (PTHSI) to reflect the child's health. In addition, caregivers self-completed the EQ-5D-5L and CarerQoL. Reports of problems on EQ dimensions were compared across age groups with the Fisher's exact test. Spearman and Pearson's correlation coefficients and Kruskal-Wallis H-test were used to explore the association between caregiver and child scores, concurrent validity, and known-group validity of the EQ-TIPS and EQ-5D-Y-3L.

RESULTS

Responses from 144 caregivers were collected, 66 for children aged 1 month to 4 years completing EQ-TIPS and 78 for children aged 5-18 years completing EQ-5D-Y-3L. The EQ-TIPS showed a higher report of no problems for social interaction for children aged 1-12 months (p = 0.040) than the older age groups, there were however no differences in the level sum score (LSS) or EQ Visual Analogue Scale scores between the age groups. The EQ-5D-Y-3L showed a significantly less report of problems for mobility (p = 0.013) and usual activities (p = 0.006) for children aged 5-7 years compared with children aged 8-12 and children aged 13-18 years. Similarly, the 5-7 years of age group had a significantly lower EQ-5D-Y-3L LSS compared with the older groups (H = 12.08, p = 0.002). The EQ-TIPS and EQ-5D-Y-3L showed moderate-to-strong associations with the PedsQL. EQ-TIPS median LSS was able to differentiate between groups on the clinical prognosis with a better health-related quality of life (HRQoL) in those where weaning from technology is possible compared with those where weaning is not possible (H = 18.98, p = 0.011). The EQ-5D-Y-3L can discriminate between breathing technology, where those with only a tracheostomy reported better HRQoL (H = 8.92, p = 0.012), and between mild and moderate clinical severity (H = 19.42, p < 0.001). Neither the PedsQL nor the PTHSI was able to discriminate between these groups across the age range. Caregiver and child HRQoL scores showed moderate-to-strong associations.

CONCLUSIONS

The EQ-TIPS and EQ-5D-Y-3L showed good validity in children dependent on the technology for breathing. The EQ-TIPS and EQ-5D-Y-3L LSS were all able to differentiate between children with known clinical variables and outperformed both the PedsQL and PTHSI, making them preferable for intervention research. The caregiver scores are associated with the child HRQoL scores and thus a spill-over should be accounted for in any interventions targeting this cohort. It is recommended that future studies investigate the reliability and responsiveness of these measures in children dependent on technology for breathing.

Psychometric Performance of Generic Childhood Multi-Attribute Utility Instruments in Preterm and Low Birthweight Populations: A Systematic Review

BACKGROUND

Individuals born preterm (gestational age < 37 weeks) and/or at low birthweight (<2500 g) are at increased risk of health impairments from birth to adulthood. This review aimed to evaluate the psychometric performance of generic childhood-specific or childhood-compatible multi-attribute utility instruments (MAUIs) in preterm and/or low birthweight (PLB) populations.

METHODS

Searches covered seven databases, including studies that targeted childhood (aged < 18 years) and/or adult (≥18 years) PLB populations; provided psychometric evidence for generic childhood-specific or compatible MAUI(s) (any language version); and published in English. Eighteen psychometric properties were evaluated using a four-part criteria rating system. Data syntheses identified psychometric evidence gaps and summarised the psychometric assessment methods/results.

RESULTS

A total of 42 studies were included, generating 178 criteria rating outputs across four MAUIs: 17D, CHSCS-PS, HUI2, and HUI3. Moreover, 64.0% of outputs concerned the HUI3 MAUI, and 38.2% related to known-group validity. There was no evidence for five psychometric properties. Only 6.7% of outputs concerned reliability and proxy-child agreement. No MAUI outperformed others across all properties. The frequently applied HUI2 and HUI3 lacked content validity evidence.

CONCLUSIONS

This psychometric evidence catalogue should inform the selection of MAUI(s) suited to the specific aims of applications targeting PLB populations. Further psychometric research is warranted to address the gaps in psychometric evidence.

Psychometric Evaluation of the PedsQL GCS and CHU9D in Australian Children and Adolescents with Common Chronic Health Conditions

BACKGROUND

Generic instruments such as the Pediatric Quality of Life Inventory™ v4.0 Generic Core Scales (PedsQL GCS) and Child Health Utility 9D (CHU9D) are widely used to assess health-related quality of life (HRQOL) of the general childhood population, but there is a paucity of information about their psychometric properties in children with specific health conditions. This study assessed psychometric properties, including acceptability, reliability, validity, and responsiveness, of the PedsQL GCS and the CHU9D in children and adolescents with a range of common chronic health problems.

METHODS

We used data from the Longitudinal Study of Australian Children (LSAC), for children aged 10-17 years with at least one of the following six parent-reported health conditions: asthma, anxiety/depression, attention deficit hyperactivity disorder (ADHD), autism/Asperger's, epilepsy, and type 1 diabetes mellitus. The LSAC used parent proxy-reported PedsQL GCS and child self-reported CHU9D assessments. The performance of each instrument (PedsQL GCS and CHU9D) for each psychometric property (acceptability, reliability, validity, and responsiveness) was assessed against established criteria.

RESULTS

The study sample included 7201 children and adolescents (mean age = 14 years; range 10.1-17.9 years; 49% female) with 15,568 longitudinal observations available for analyses. Across the six health conditions, acceptability of the PedsQL GCS was high, while acceptability for the CHU9D was mixed. Both the PedsQL GCS and CHU9D showed strong internal consistency (Cronbach's alpha range: PedsQL GCS = 0.70-0.95, CHU9D = 0.76-0.84; item-total correlations range: PedsQL GCS = 0.35-0.84, CHU9D = 0.32-0.70). However, convergent validity for both the PedsQL GCS and CHU9D was generally weak (Spearman's correlations ≤ 0.3). Known group validity was strong for the PedsQL GCS (HRQOL differences were detected for children with and without asthma, anxiety/depression, ADHD, autism/Asperger's, and epilepsy). CHU9D was only able to discriminate between children with and without anxiety/depression, ADHD, and autism/Asperger's. The responsiveness of both the PedsQL GCS and CHU9D was variable across the six conditions, and most of the estimated effect sizes were relatively small (< 0.5).

CONCLUSION

This study expands the evidence base of psychometric performance of the PedsQL GCS and CHU9D and can aid in appropriate HRQOL instrument selection for the required context by researchers and clinicians.

Including Young Children in the Development and Testing of Patient Reported Outcome (PRO) Instruments: A Scoping Review of Children's Involvement and Qualitative Methods

BACKGROUND

Qualitative research during the development/testing of Patient Reported Outcome Measures (PROMs) is recommended to support content validity. However, it is unclear if and how young children (≤ 7 years) can be involved in this research because of their unique cognitive needs.

OBJECTIVES

Here we investigate the involvement of children (≤ 7 years) in qualitative research for PROM development/testing. This review aimed to identify (1) which stages of qualitative PROM development children ≤ 7 years had been involved in, (2) which subjective health concepts had been explored within qualitative PROM development with this age group, and (3) which qualitative methods had been reported and how these compared with existing methodological recommendations.

METHODS

This scoping review systematically searched three electronic databases (searches re-run prior to final analysis on 29 June 2022) with no date restrictions. Included studies had samples of at least 75% aged ≤ 7 years or reported distinct qualitative methods for children ≤ 7 years in primary qualitative research to support concept elicitation or PROM development/testing. Articles not in English and PROMs that did not enable children ≤ 7 years to self-report were excluded. Data on study type, subjective health and qualitative methods were extracted and synthesised descriptively. Methods were compared with recommendations from guidance.

RESULTS

Of 19 included studies, 15 reported concept elicitation research and 4 reported cognitive interviewing. Most explored quality of life (QoL)/health-related quality of life (HRQoL). Some concept elicitation studies reported that creative/participatory activities had supported children's engagement, but results and reporting detail varied considerably across studies. Cognitive interviewing studies reported less methodological detail and fewer methods adapted for young children compared with concept elicitation studies. They were limited in scope regarding assessments of content validity, mostly focussing on clarity while relevance and comprehensiveness were explored less.

DISCUSSION

Creative/participatory activities may be beneficial in concept elicitation research with children ≤ 7 years, but future research needs to explore what contributes to the success of young children's involvement and how researchers can adopt flexible methods. Cognitive interviews with young children are limited in frequency, scope and reported methodological detail, potentially impacting PROM content validity for this age group. Without detailed reporting, it is not possible to determine the feasibility and usefulness of children's (≤ 7 years) involvement in qualitative research to support PROM development and assessment.

Use of Utility and Disability Weights in Economic Evaluation of Pediatric Vaccines

OBJECTIVE

To describe how utility weights and disability weights have been used in the context of quality-adjusted life-years (QALYs) and disability-adjusted life-years (DALYs)-based cost-effectiveness analysis (CEA) of pediatric vaccines for infectious diseases and assess the comparability between weights.

METHODS

A systematic review was conducted of CEAs of pediatric vaccines for 16 infectious diseases, published between January 2013 and December 2020 and using QALYs or DALYs as outcome measure. Data on values and sources of weights for the estimation of QALYs and DALYs were extracted from studies and compared across similar health states. Reporting was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

RESULTS

Out of 2154 articles identified, 216 CEAs met our inclusion criteria. Of the included studies, 157 used utility weights and 59 used disability weights in their valuation of health states. In QALY studies, the source, background, who's preferences (adults'/children's) were applied and adjustments made to utility weights were poorly reported. In DALY studies, the Global Burden of Disease study was most often referenced. Valuation weights for similar health states varied within QALY studies and between DALY and QALY studies, but no systematic differences were identified.

CONCLUSIONS

This review identified considerable gaps in the way valuation weights are used and reported on in CEA. The nonstandardized use of weights may lead to different conclusions about cost-effectiveness of vaccines and policy decisions.

Systematic Review of the Psychometric Performance of Generic Childhood Multi-attribute Utility Instruments

BACKGROUND

Childhood multi-attribute utility instruments (MAUIs) can be used to measure health utilities in children (aged ≤ 18 years) for economic evaluation. Systematic review methods can generate a psychometric evidence base that informs their selection for application. Previous reviews focused on limited sets of MAUIs and psychometric properties, and only on evidence from studies that directly aimed to conduct psychometric assessments.

OBJECTIVE

This study aimed to conduct a systematic review of psychometric evidence for generic childhood MAUIs and to meet three objectives: (1) create a comprehensive catalogue of evaluated psychometric evidence; (2) identify psychometric evidence gaps; and (3) summarise the psychometric assessment methods and performance by property.

METHODS

A review protocol was registered with the Prospective Register of Systematic Reviews (PROSPERO; CRD42021295959); reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline. The searches covered seven academic databases, and included studies that provided psychometric evidence for one or more of the following generic childhood MAUIs designed to be accompanied by a preference-based value set (any language version): 16D, 17D, AHUM, AQoL-6D, CH-6D, CHSCS-PS, CHU9D, EQ-5D-Y-3L, EQ-5D-Y-5L, HUI2, HUI3, IQI, QWB, and TANDI; used data derived from general and/or clinical childhood populations and from children and/or proxy respondents; and were published in English. The review included 'direct studies' that aimed to assess psychometric properties and 'indirect studies' that generated psychometric evidence without this explicit aim. Eighteen properties were evaluated using a four-part criteria rating developed from established standards in the literature. Data syntheses identified psychometric evidence gaps and summarised the psychometric assessment methods/results by property.

RESULTS

Overall, 372 studies were included, generating a catalogue of 2153 criteria rating outputs across 14 instruments covering all properties except predictive validity. The number of outputs varied markedly by instrument and property, ranging from 1 for IQI to 623 for HUI3, and from zero for predictive validity to 500 for known-group validity. The more recently developed instruments targeting preschool children (CHSCS-PS, IQI, TANDI) have greater evidence gaps (lack of any evidence) than longer established instruments such as EQ-5D-Y, HUI2/3, and CHU9D. The gaps were prominent for reliability (test-retest, inter-proxy-rater, inter-modal, internal consistency) and proxy-child agreement. The inclusion of indirect studies (n = 209 studies; n = 900 outputs) increased the number of properties with at least one output of acceptable performance. Common methodological issues in psychometric assessment were identified, e.g., lack of reference measures to help interpret associations and changes. No instrument consistently outperformed others across all properties.

CONCLUSION

This review provides comprehensive evidence on the psychometric performance of generic childhood MAUIs. It assists analysts involved in cost-effectiveness-based evaluation to select instruments based on the application-specific minimum standards of scientific rigour. The identified evidence gaps and methodological issues also motivate and inform future psychometric studies and their methods, particularly those assessing reliability, proxy-child agreement, and MAUIs targeting preschool children.

Reliability, acceptability, validity and responsiveness of the CHU9D and PedsQL in the measurement of quality of life in children and adolescents with overweight and obesity

BACKGROUND

The Paediatric Quality of life Inventory (PedsQL^TM) Generic Core Scales and the Child Health Utilities 9 Dimensions (CHU9D) are two paediatric health-related quality of life (HRQoL) measures commonly used in overweight and obesity research. However, no studies have comprehensively established the psychometric properties of these instruments in the context of paediatric overweight and obesity. The aim of this study was to assess the reliability, acceptability, validity and responsiveness of the PedsQL and the CHU9D in the measurement of HRQoL among children and adolescents living with overweight and obesity.

SUBJECTS/METHODS

Subjects were 6544 child participants of the Longitudinal Study of Australian Children, with up to 3 repeated measures of PedsQL and CHU9D and aged between 10 and 17 years. Weight and height were measured objectively by trained operators, and weight status determined using World Health Organisation growth standards. We examined reliability, acceptability, known group and convergent validity and responsiveness, using recognised methods.

RESULTS

Both PedsQL and CHU9D demonstrated good internal consistency reliability, and high acceptability. Neither instrument showed strong convergent validity, but PedsQL appears to be superior to the CHU9D in known groups validity and responsiveness. Compared with healthy weight, mean (95%CI) differences in PedsQL scores for children with obesity were: boys -5.6 (-6.2, -4.4); girls -6.7 (-8.1, -5.4) and differences in CHU9D utility were: boys -0.02 (-0.034, -0.006); girls -0.035 (-0.054, -0.015). Differences in scores for overweight compared with healthy weight were: PedsQL boys -2.2 (-3.0, -1.4) and girls -1.3 (-2.0, -0.6) and CHU9D boys: no significant difference; girls -0.014 (-0.026, -0.003).

CONCLUSION

PedsQL and CHU9D overall demonstrated good psychometric properties, supporting their use in measuring HRQoL in paediatric overweight and obesity. CHU9D had poorer responsiveness and did not discriminate between overweight and healthy weight in boys, which may limit its use in economic evaluation.

A comparison of the Child Health Utility 9D and the Health Utilities Index for estimating health utilities in pediatric inflammatory bowel disease

PURPOSE

Health utilities are challenging to ascertain in children and have not been studied in pediatric Crohn's disease (CD) and ulcerative colitis (UC). The objective was to assess discriminative validity by comparing utilities elicited using the Child Health Utility-9 Dimension (CHU9D) to the Health Utilities Index (HUI) across multiple disease activity scales in pediatric UC and CD.

METHODS

Preference-based instruments were administered to 188 children with CD and 83 children with UC aged 6 to 18 years. Utilities were calculated using CHU9D adult and youth tariffs, and HUI2 and HUI3 algorithms in children with inactive (quiescent) and active (mild, moderate, and severe) disease. Differences between instruments, tariff sets and disease activity categories and were tested statistically.

RESULTS

In CD and UC, all instruments detected significantly higher utilities for inactive compared to active disease (p < 0.05). Mean utilities for quiescent disease ranged from 0.810 (SD 0.169) to 0.916 (SD 0.121) in CD and from 0.766 (SD 0.208) to 0.871 (SD 0.186) in UC across instruments. Active disease mean utilities ranged from 0.694 (SD 0.212) to 0.837 (SD 0.168) in CD and from 0.654 (SD 0.226) to 0.800 (SD 0.128) in UC.

CONCLUSION

CHU9D and HUI discriminated between levels of disease activity in CD and UC regardless of the clinical scale used, with the CHU9D youth tariff most often displaying the lowest utilities for worse health states. Distinct utilities for different IBD disease activity states can be used in health state transition models evaluating the cost-effectiveness of treatments for pediatric CD and UC.

Cross-Cultural Adaptation and Validation of the EuroQoL Toddler and Infant Populations Instrument Into Afrikaans for South Africa

OBJECTIVES

The EuroQol Group is exploring the development of a health-related quality of life measure for toddlers and infant populations (EuroQoL Toddler and Infant Populations [EQ-TIPS]) aged 0 to 36 months. This study aimed to report on the cross-cultural adaptation and validity of the South African Afrikaans EQ-TIPS.

METHODS

The development of the Afrikaans EQ-TIPS followed the EuroQol guidelines including forward-backward translation and cognitive interviews with 10 caregivers of children aged 0 to 36 months. Thereafter, 162 caregivers of children 0 to 36 months of age were recruited from a pediatric hospital inpatient and outpatient facility. The EQ-TIPS; Ages and Stages Questionnaire; face, legs, activity, cry, and consolability; and dietary information were completed by all caregivers. The distribution of dimension scores, Spearman's correlation, analysis of variance, and regression analysis were used to explore the validity of the EQ-TIPS.

RESULTS

The descriptive system of the EQ-TIPS was generally well understood and accepted by caregivers. The correlation coefficients for concurrent validity were significant and moderate for pain and weak and significant for the other dimensions hypothesized to correlate. Known groups were compared and inpatients had a significantly higher report of pain (χ² = 7.47, P = .024) and more problems reported across all EQ-TIPS dimensions (recorded on the level sum score) (Kruskal Wallis H = 3.809, P = .05) and reported significantly worse health on the visual analog scale (Kruskal Wallis H = 15.387, P < .001). There were no age-related differences except for a lower report of problems with movement in the 0- to 12-month group (χ² = 10.57, P = .032).

CONCLUSION

The Afrikaans version of the EQ-TIPS is well understood and accepted by caregivers and valid for use with children aged 0 to 36 months in South Africa.

A Comparison of Preference-Based, Generic and Disease-Specific Health-Related Quality of Life in Pediatric Inflammatory Bowel Disease

Objective

Generic preference-based HRQOL assessments used expressly for economic evaluation have not been examined in pediatric Crohn’s disease (CD) and ulcerative colitis (UC). The objective was to further assess the construct validity of preference-based HRQOL measures in pediatric IBD by comparing the Child Health Utility 9 Dimensions (CHU9D) and Health Utilities Index (HUI) to the disease-specific IMPACT-III and to the generic PedsQL in children with CD and with UC.

Methods

The CHU9D, HUI, IMPACT-III and/or PedsQL were administered to Canadian children aged 6 to 18 years with CD and UC. CHU9D total and domain utilities were calculated using adult and youth tariffs. HUI total and attribute utilities were determined for the HUI2 and HUI3. Total scores for IMPACT-III and PedsQL were determined. Spearman correlations were calculated between generic preference-based utilities and the IMPACT-III and PedsQL scores.

Results

The questionnaires were administered to 157 children with CD and 73 children with UC. Moderate to strong correlations were observed between the CHU9D, HUI2, HUI3 and the disease-specific IMPACT-III or generic PedsQL. As hypothesized, domains with similar constructs demonstrated stronger correlations, such as the Pain and Well-being domains.

Conclusions

While all questionnaires were moderately correlated with the IMPACT-III and PedsQL questionnaires, the CHU9D using youth tariffs and the HUI3 were most strongly correlated and would be suitable choices to generate health utilities for children with CD or UC for the purpose of economic evaluation of treatments in pediatric IBD.

Value Set for the EQ-5D-Y-3L in Hungary

BACKGROUND

The Hungarian health technology assessment guidelines recommend the use of the EuroQol instrument family in quality-adjusted life-year calculations. However, no national value set exists for the EQ-5D-Y-3L or any other youth-specific instrument.

OBJECTIVE

This study aims to develop a national value set of the EQ-5D-Y-3L for Hungary based on preferences of the general adult population.

METHODS

This study followed the international valuation protocol for the EQ-5D-Y-3L. Two independent samples, representative of the Hungarian general adult population in terms of age and sex were recruited to complete online discrete choice experiment (DCE) tasks and composite time trade-off (cTTO) tasks by computer-assisted personal interviews. Adults valued hypothetical EQ-5D-Y-3L health states considering the health of a 10-year-old child. DCE data were modelled using a mixed logit model with random-correlated coefficients. Latent DCE utility estimates were mapped onto mean observed cTTO utilities using ordinary least squares regression.

RESULTS

Overall, 996 and 200 respondents completed the DCE and cTTO surveys, respectively. For each domain, the value set resulted in larger utility decrements with more severe response levels. The relative importance of domains by level 3 coefficients was as follows: having pain or discomfort > feeling worried, sad or unhappy > mobility > doing usual activities > looking after myself. Overall, 12.3% of all health states had negative utilities in the value set, with the worst health state having the lowest predicted utility of - 0.485.

CONCLUSION

This study developed a national value set of the EQ-5D-Y-3L for Hungary. The value set enables to evaluate the cost utility of health technologies for children and adolescents based on societal preferences in Hungary.

Comparison of the EQ-5D-Y-5L, EQ-5D-Y-3L and PedsQL in children and adolescents

Background

There is an increased use of Patient-Reported Outcome Measures (PROMs) in children and adolescents. The aim of this study was to compare the feasibility, concurrent validity and known-group validity of the EQ-5D-Y-3L (Y-3L), EQ-5D-Y-5L (Y-5L) and PedsQL self-report PROMs.

Methods

Five hundred and fifty children and adolescents, aged 8–15-years, with acute and chronic health conditions and a general population sample were recruited from schools and hospitals in Cape Town South Africa. All respondents self-completed the Y-5L, PedsQL, Self-Rated Health Question and Y-3L. Feasibility of the measures was determined by comparing the number of missing responses. Convergent validity was assessed by Spearman’s and Intra-class correlations on the corresponding items and summary scores respectively. Known-groups validity across health conditions was assessed across the summary scores of the measures with analysis of variance (ANOVA).

Results

The Y-3L and Y-5L had a total of 1% and 3.5% missing responses compared to 19% on the PedsQL. Similar items on the PedsQL and Y-3L/Y-5L showed high correlations (> 0.5) and related items showed moderate correlations (0.3). PedsQL total score was moderately and significantly associated with Y-3L and Y-5L level sum and VAS scores. The Y-3L and Y-5L level sum and VAS scores showed significant differences between known health groups whereas the PedsQL only showed differences between those with acute and chronic illness.

Conclusion

The results of this study show that the Y-3L and Y-5L showed comparable psychometric validity to the PedsQL. When considering the choice between the PedsQL, Y-5L and Y-3L these study results indicate that the EQ-5D-Y instruments (Y-3L and Y-5L) are recommended for studies assessing known-group validity or where missing data should be minimised. The PedsQL generic measure may be preferable in future studies including the general population where a ceiling effect is anticipated. When considering the choice between the Y-5L and the Y-3L there was no systematic difference in the validity between these instruments or between the Y-3L or Y-5L and the PedsQL. Thus, the selection of EQ-5D-Y measures to include in future studies should be guided by the characteristics of the population to be tested.

Designing Intergenerational Spaces: What to Learn From Children

Objectives:

Adopting recommendations of the United Nations Committee on the Rights of the Child, this study addresses the value of children’s input on the architectural design of the built environment of intergenerational shared sites and the intergenerational interactions that took place there.

Background:

Intergenerational programs bring children and older adults together, inviting them to interact, exchange ideas and support each other. Most intergenerational programs are planned by staff and often take place in a multipurpose room without direct input from child or older adult participants.

Methods:

Data for this study were collected through interviews and drawings from 16 children at three intergenerational centers in Hawaii, Kansas, and Virginia. The interviews were transcribed, analyzed, coded, and categorized. Child development experts analyzed the drawings to better understand how children experience their surrounding environment.

Results:

Four themes emerged from the triangulated data: (1) outdoor spaces offer rich opportunities for shared programming, (2) children enjoy sharing meals and snacks with intergenerational partners, (3) children recognize environmental features that facilitate or limit intergenerational interaction, and (4) varied spaces support to informal, brief intergenerational interaction. Our findings provide evidence in the value of involving children in designing intergenerational centers and programming.

Conclusion:

The children who participated in this study provided meaningful insight reflecting the experience of intergenerational activities and the impacts of the built environment on the quality and variety of these interactions.

The critical role of mixed methods research in developing valid and reliable patient-reported outcome measures

Randomised controlled clinical trials provide the gold standard for evidence underpinning clinical guidelines and patient centred care. However, this is only true when they are robustly designed, conducted and reported and then only if they include outcomes that are important to patients and clinicians. Important outcomes include those that measure impact on patient experience, quality of life, overall well-being, and physical, social, cognitive and emotional functioning, all of which require patient reported outcome measures (PROMs). Patient centred care must be underpinned by objective evidence of the effect of interventions on outcomes that are important to patients. Evidence for patient reported outcomes must be supported by valid and reliable PROMs. Importantly the PROM must reflect patient experience of the impact of the intervention on the outcome and enable quantitative evaluation of that impact. The purpose of this paper is to highlight the critical role of mixed methods research in developing PROMs that are valid (measure what they purport to measure), acceptable to those reporting the outcome and able to reliably detect meaningful differences between individuals with different conditions or severity and with time. This can only be achieved through a structured mixed methods program combining qualitative and quantitative research techniques.

Valuing EQ-5D-Y: the current state of play

BACKGROUND

For nearly a decade, value sets for the EQ-5D-Y were not available, reflecting challenges in valuing child HRQoL. A methodological research programme led to publication of a valuation protocol in 2020, which was rapidly taken up by local study teams. By the end of 2022, between 11 and 17 EQ-5D-Y value sets will be available, more than for any other child HRQoL measure. It is timely to review the experience of those using the protocol to identify early learnings and remaining issues where more research is needed.

METHODS

In June 2021, the EuroQol Group organised a three-day workshop, bringing together all those involved in EQ-5D-Y value set studies and related methodological research concerning EQ-5D-Y and valuation. Workshop discussions were captured by note taking and recording all sessions and online chat. A narrative summary of all sessions was produced and synthesised to identify points of agreement and aspects of methods where uncertainty remains.

RESULTS

There was broad agreement that DCE is working well as the principal valuation method. However, the most appropriate means of anchoring the latent scale values produced by DCE remains unclear. Some studies have deviated from the protocol by extending the number of states included in TTO tasks, to better support modelling of DCE and TTO. There is ongoing discussion about the relative merits of alternative variants of TTO and other methods for anchoring. Very few studies have consulted with local end-users to gauge the acceptability of methods used to value EQ-5D-Y.

CONCLUSIONS

Priority areas for research include testing alternative methods for anchoring DCE data; exploring the preferences of adolescents; and scale differences in values for EQ-5D-Y and adult EQ-5D states, and implications of such differences for the use of EQ-5D-Y values in HTA. Given the normative elements of the protocol, engaging with HTA bodies and other local users should be the first step for all future value set studies. Value sets undertaken to date are for the three-level EQ-5D-Y. However, the issues discussed in this paper are equally relevant to valuation of the five-level version of EQ-5D-Y; indeed, similar challenges are encountered valuing any measure of child HRQoL.

Preference Elicitation Techniques Used in Valuing Children's Health-Related Quality-of-Life: A Systematic Review

BACKGROUND AND OBJECTIVES

Valuing children's health states for use in economic evaluations is globally relevant and is of particular relevance in jurisdictions where a cost-utility analysis is the preferred form of analysis for decision making. Despite this, the challenges with valuing child health mean that there are many remaining questions for debate about the approach to elicitation of values. The aim of this paper was to identify and describe the methods used to value children's health states and the specific issues that arise in the use of these methods.

METHODS

We conducted a systematic search of electronic databases to identify studies published in English since 1990 that used preference elicitation methods to value child and adolescent (under 18 years of age) health states. Eligibility criteria comprised valuation studies concerning both child-specific patient-reported outcome measures and child health states defined in other ways, and methodological studies of valuation approaches that may or may not have yielded a value set algorithm.

RESULTS

A total of 77 eligible studies were identified from which data on country setting, aims, condition (general population or clinically specific), sample size, age of respondents, the perspective that participants were asked to adopt, source of values (respondents who completed the preference elicitation tasks) and methods questions asked were extracted. Extracted data were classified and evaluated using narrative synthesis methods. The studies were classified into three groups: (1) studies comparing elicitation methods (n = 30); (2) studies comparing perspectives (n = 23); and (3) studies where no comparisons were presented (n = 26); selected studies could fall into more than one group. Overall, the studies varied considerably both in methods used and in reporting. The preference elicitation tasks included time trade-off, standard gamble, visual analogue scaling, rating/ranking, discrete choice experiments, best-worst scaling and willingness to pay elicited through a contingent valuation. Perspectives included adults' considering the health states from their own perspective, adults taking the perspective of a child (own, other, hypothetical) and a child/adolescent taking their own or the perspective of another child. There was some evidence that children gave lower values for comparable health states than did adults that adopted their own perspective or adult/parents that adopted the perspective of children.

CONCLUSIONS

Differences in reporting limited the conclusions that can be formed about which methods are most suitable for eliciting preferences for children's health and the influence of differing perspectives and values. Difficulties encountered in drawing conclusions from the data (such as lack of consensus and poor reporting making it difficult for users to choose and interpret available values) suggest that reporting guidelines are required to improve the consistency and quality of reporting of studies that value children's health using preference-based techniques.

Methodological challenges surrounding QALY estimation for paediatric economic evaluation

Cost-utility analysis remains the preferred form of economic evaluation for health technology assessment, pricing and reimbursement authorities in several countries. The results of cost-utility analyses are commonly expressed in terms of incremental cost per quality-adjusted life year (QALY) gained where the QALY combines length of life and health-related quality of life in a single metric. This commentary provides an overview of key methodological challenges surrounding QALY estimation for paediatric economic evaluation. These challenges include issues surrounding the relevant attributes to incorporate into measurement instruments, appropriate respondents for the measurement and valuation tasks, perspectives adopted when completing valuation tasks, potential sources of bias in the description and valuation processes, and the paucity of psychometric evidence for existing measures. In addition, the commentary considers methodological challenges raised by research aimed at assessing whether a QALY gain by a child should be valued equally to a QALY gain by an adult.