Selection and validation of a classification system for a child-centred preference-based measure of oral health-related quality of life specific to dental caries

A scoping review to create a framework for the steps in developing condition-specific preference-based instruments de novo or from an existing non-preference-based instrument: use of item response theory or Rasch analysis

BACKGROUND

There is no widely accepted framework to guide the development of condition-specific preference-based instruments (CSPBIs) that includes both de novo and from existing non-preference-based instruments. The purpose of this study was to address this gap by reviewing the published literature on CSPBIs, with particular attention to the application of item response theory (IRT) and Rasch analysis in their development.

METHODS

A scoping review of the literature covering the concepts of all phases of CSPBI development and evaluation was performed from MEDLINE, Embase, PsychInfo, CINAHL, and the Cochrane Library, from inception to December 30, 2022.

RESULTS

The titles and abstracts of 1,967 unique references were reviewed. After retrieving and reviewing 154 full-text articles, data were extracted from 109 articles, representing 41 CSPBIs covering 21 diseases or conditions. The development of CSPBIs was conceptualized as a 15-step framework, covering four phases: 1) develop initial questionnaire items (when no suitable non-preference-based instrument exists), 2) establish the dimensional structure, 3) reduce items per dimension, 4) value and model health state utilities. Thirty-nine instruments used a type of Rasch model and two instruments used IRT models in phase 3.

CONCLUSION

We present an expanded framework that outlines the development of CSPBIs, both from existing non-preference-based instruments and de novo when no suitable non-preference-based instrument exists, using IRT and Rasch analysis. For items that fit the Rasch model, developers selected one item per dimension and explored item response level reduction. This framework will guide researchers who are developing or assessing CSPBIs.

Developing the Breast Utility Instrument to Measure Health-Related Quality-of-Life Preferences in Patients with Breast Cancer: Selecting the Item for Each Dimension

Introduction. Generic preference-based instruments inadequately measure breast cancer (BrC) health-related quality-of-life preferences given advances in therapy. Our overall purpose is to develop the Breast Utility Instrument (BUI), a BrC-specific preference-based instrument. This study describes the selection of the BUI items. Methods. A total of 408 patients from diverse BrC health states completed the EORTC QLQ-C30 and BR45 (breast module). For each of 10 dimensions previously assessed with confirmatory factor analysis, we evaluated data fit to the Rasch model based on global model and item fit, including threshold ordering, item residuals, infit and outfit, differential item functioning (age), and unidimensionality. Misfitting items were removed iteratively, and the model fit was reassessed. From items fitting the Rasch model, we selected 1 item per dimension based on high patient- and clinician-rated item importance, breadth of item thresholds, and clinical relevance. Results. Global model fit was good in 7 and borderline in 3 dimensions. Separation index was acceptable in 4 dimensions. Item selection criteria were maximized for the following items: 1) physical functioning (trouble taking a long walk), 2) emotional functioning (worry), 3) social functioning (interfering with social activities), 4) pain (having pain), 5) fatigue (tired), 6) body image (dissatisfied with your body), 7) systemic therapy side effects (hair loss), 8) sexual functioning (interest in sex), 9) breast symptoms (oversensitive breast), and 10) endocrine therapy symptoms (problems with your joints). Conclusions. We propose 10 items for the BUI. Our next steps include assessing the measurement properties prior to eliciting preference weights of the BUI.

Highlights

A previous confirmatory factor analysis established 10 dimensions of the European Organisation for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ-C30) and its breast module (BR45). In this study, we selected 1 item per dimension based on fit to the Rasch model, patient- and clinician-rated item importance, breadth of item thresholds, and clinical relevance. These items form the core of the future Breast Utility Instrument (BUI). The future BUI will be a novel breast cancer–specific preference-based instrument that potentially will better reflect women’s preferences in clinical decision making and cost utility analyses.

Economic Evaluation of the Protecting Teeth @ 3 Randomized Controlled Trial

INTRODUCTION

An economic evaluation (EE) was conducted alongside a randomized controlled trial (the Protecting Teeth @ 3 Study [PT@3]), exploring the additional preventive value of fluoride varnish (FV) application at 6-monthly intervals in nursery schools compared to treatment as usual (TAU) in the same nurseries. TAU represented a multicomponent national child oral health improvement intervention, the Childsmile program, apart from nursery FV.

METHODS

The EE was a within-trial cost-utility analysis (CUA) comparing the FV and TAU groups. The CUA was conducted from a National Health Service perspective and followed relevant methods guidance. Within-trial costs included intervention costs and health care resource use costs. Health outcomes were expressed in quality-adjusted life years (QALYs) accrued over the 2-y follow-up period. The Child Health Utility 9 Dimensions questionnaire was used to obtain utility scores. National reference costs were used, a discount rate of 1.5% for public health interventions was adopted, multiple imputation methods for missing data were employed, sensitivity analyses were conducted, and incremental cost-utility ratios were calculated.

RESULTS

Data from 534 participants from the 2014-2015 PT@3 intake were used in the EE analyses, n = 265 (50%) in the FV arm and n = 269 (50%) in the TAU arm. Mean incremental cost per child in the FV arm was £68.37 (P = 0.382; 95% confidence interval [CI], -£18.04 to £143.82). Mean incremental QALY was -0.004 (P = 0.636; 95% CI, -0.016 to 0.007). The probability that the FV intervention was cost-effective at the UK £20,000 threshold was 11.3%.

CONCLUSION

The results indicate that applying FV in nurseries in addition to TAU (all other components of Childsmile, apart from nursery FV) would not be deemed cost-effective given current UK thresholds. In view of previously proven clinical effectiveness and economic worthiness of the universal nursery toothbrushing component of Childsmile, continuation of the additional, targeted nursery FV component in its pre-COVID-19 form should be reviewed given its low probability of cost-effectiveness.

KNOWLEDGE TRANSFER STATEMENT

The results of this study can be used by child oral health policy makers and dental public health professionals. They can form part of the evidence to inform the Scottish, UK, and international guidance on community-based child oral health promotion programs.

Adolescent valuation of CARIES-QC-U: a child-centred preference-based measure of dental caries

Objectives

This study develops an adolescent value set for a child-centred dental caries-specific measure of oral health-related quality of life (OHRQoL) based upon CARIES-QC (Caries Impacts and Experiences Questionnaire for Children). This study develops a new approach to valuing child health by eliciting adolescent preferences and anchoring these onto the 1–0 full health-dead QALY (quality adjusted life year) scale using ordinal adult preferences.

Methods

Two online surveys were created to elicit preferences for the CARIES-QC classification system. The first comprised best–worst scaling (BWS) tasks for completion by adolescents aged 11–16 years. The second comprised discrete choice experiment tasks with a duration attribute (DCE_TTO) for completion by adults aged over 18 years. Preferences were modelled using the conditional logit model. Mapping regressions anchored the adolescent BWS data onto the QALY scale using adult DCE_TTO values, since the BWS survey data alone cannot generate anchored values.

Results

723 adolescents completed the BWS survey and 626 adults completed the DCE_TTO survey. The samples were representative of UK adolescent and adult populations. Fully consistent and robust models were produced for both BWS and DCE_TTO data. BWS preferences were mapped onto DCE_TTO values, resulting utility estimates for each health state defined by the classification system.

Conclusion

This is the first measure with predetermined scoring based on preferences to be developed specifically for use in child oral health research, and uses a novel technique to generate a value set using adolescent preferences. The estimates can be used to generate QALYs in economic evaluations of interventions to improve children’s oral health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12955-022-01918-w.

Development of a classification (descriptive) system for a preference-based quality of life measure for dental caries (dental caries utility index) among adolescents

OBJECTIVES

Preference-based quality-of-life measures (PBMs) have been developed in many clinical areas to aid estimation of more accurate utility values for economic evaluations. Existing oral health-related quality-of-life (OHRQoL) instruments are non-PBM and hence, cannot be used to generate utility values. The objective of this study was to develop a classification system for a new PBM (dental caries utility index-DCUI) for the most prevalent childhood oral health condition: dental caries.

METHODS

Possible domains and items to be included in the classification system were identified based on the reviewing available pediatric non-PBM OHRQoL instruments, studies eliciting utility values for oral health outcomes and clinical dentistry textbooks and based on the findings, a draft classification system was developed. To refine the draft classification system, semi-structured interviews were conducted among a convenience sample of 15 12-17-year-old adolescents who had experience with dental caries. The classification system was further refined and validated by a group of dental experts, using a modified Delphi technique.

RESULTS

The classification system comprised five items (pain/discomfort, difficulty in eating food/drinking, worried, ability to participate in activities, and appearance) and each item had a four-level response scale.

CONCLUSION

The classification system developed herein is considered an amenable tool for the subsequent development of a new PBM for dental caries. Once the scoring algorithm is completed, the classification system can be used to incorporate economic evaluations of dental caries health interventions.

A systematic review of the quality and scope of decision modelling studies in child oral health research

Background

Decision analytic models are often used in economic evaluations to estimate long-term costs and effects of treatment which span beyond the time-frame of a clinical trial, therefore providing a better understanding of the long-term implications of decisions that conventional trial-based economic evaluations fail to provide. This is particularly relevant for considering oral health interventions in children as treatments may affect adult oral health. However, in the field of child oral health there has not been an evaluation of the quality and scope of decision analytical models which extend into adulthood. The aim of this review is to examine the scope and quality of decision modelling studies, with horizons extending into adulthood, within the field of child oral health.

Methods

The following databases were searched: NHS Economic Evaluation Database (CRD York), MEDLINE, EMBASE, CINAHL, Web of Science, Scopus, the Cochrane Library and Econlit. Full economic evaluations, in the field of child oral health, published after 1997 which included a decision model with a horizon that extended beyond the age of 18 years old were included. Included studies were appraised against the Drummond checklist and the Consolidated Health Economic Evaluation Reporting Standards by calibrated reviewers.

Results

Four hundred studies were identified, of which nine met the inclusion criteria. Of the nine, eight were cost-effectiveness models. The majority focussed on the prevention or management of dental caries. The mean percentage of applicable Drummond checklist criteria met by the studies in this review was 82% (median = 85%, range = 54–100%). Discounting of costs and performing an incremental analysis were noted as key methodological weaknesses. The mean percentage of applicable CHEERS criteria met by each study was 82% (median = 87%, range = 32–96%). Justifying the type of model, analytical methods used, and sources of funding were most commonly unreported.

Conclusions

There is a paucity of decision analytical models in the field of child oral health. Most of those that are available are of high methodological and reporting quality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01680-3.