Sources and Characteristics of Utility Weights for Economic Evaluation of Pediatric Vaccines: A Systematic Review

A Qualitative Investigation to Develop an Adapted Version of the EQ-5D-Y-3L for Use in Children Aged 2-4 Years

OBJECTIVES

Few preference-weighted health-related quality-of-life measures exist for children under 5 years of age. Young children are substantial consumers of healthcare services. This project aims to assess EQ-5D-Y-3L's appropriateness in children aged 2 to 4 years and to coproduce with parents a suitable adaptation.

METHODS

Purposive sampling at the Murdoch Children's Research Institute and Royal Children's Hospital was used to recruit parents or carers of children aged 2 to 4 years in Australia. Online focus groups were conducted consisting of 13 parents of healthy children, and 6 parents of children with moderate to severe health conditions. Parents provided feedback on each dimension of the proxy EQ-5D-Y-3L. Recordings were transcribed and thematic analysis was conducted. Qualitative findings guided the design of adaptations to the instrument. The adaptations were piloted to obtain feedback and refined to improve language translatability and comparability with other EuroQol instruments.

RESULTS

The adapted EQ-5D-Y-3L was considered generally acceptable by the parents. Parents provided a wide range of examples of how each domain related to their children, with varied examples provided across ages 2 to 4 years and health status. Additional or alternative wording was suggested by parents to improve the applicability of the instrument to this age group. One example of this was the change of the domain wording "walking about" to "movement"-ID5:"In this age group, movement is more important than walking."

CONCLUSIONS

The adapted EQ-5D-Y-3L has improved relevance for 2-4-year olds and appears easy to complete. Further testing of the adapted instrument is required to evaluate acceptability, reliability, and validity.

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.

Lifetime quality-adjusted life years lost due to genital herpes acquired in the United States in 2018: a mathematical modeling study

Background

Genital herpes (GH), caused by herpes simplex virus type 1 and type 2 (HSV-1, HSV-2), is a common sexually transmitted disease associated with adverse health outcomes. Symptoms associated with GH outbreaks can be reduced by antiviral medications, but the infection is incurable and lifelong. In this study, we estimate the long-term health impacts of GH in the United States using quality-adjusted life years (QALYs) lost.

Methods

We used probability trees to model the natural history of GH secondary to infection with HSV-1 and HSV-2 among people aged 18-49 years. We modelled the following outcomes to quantify the major causes of health losses following infection: symptomatic herpes outbreaks, psychosocial impacts associated with diagnosis and recurrences, urinary retention caused by sacral radiculitis, aseptic meningitis, Mollaret's meningitis, and neonatal herpes. The model was parameterized based on published literature on the natural history of GH. We summarized losses of health by computing the lifetime number of QALYs lost per genital HSV-1 and HSV-2 infection, and we combined this information with incidence estimates to compute the total lifetime number of QALYs lost due to infections acquired in 2018 in the United States.

Findings

We estimated 0.05 (95% uncertainty interval (UI) 0.02-0.08) lifetime QALYs lost per incident GH infection acquired in 2018, equivalent to losing 0.05 years or about 18 days of life for one person with perfect health. The average number of QALYs lost per GH infection due to genital HSV-1 and HSV-2 was 0.01 (95% UI 0.01-0.02) and 0.05 (95% UI 0.02-0.09), respectively. The burden of genital HSV-1 is higher among women, while the burden of HSV-2 is higher among men. QALYs lost per neonatal herpes infection was estimated to be 7.93 (95% UI 6.63-9.19). At the population level, the total estimated lifetime QALYs lost as a result of GH infections acquired in 2018 was 33,100 (95% UI 12,600-67,900) due to GH in adults and 3,140 (95% UI 2,260-4,140) due to neonatal herpes. Results were most sensitive to assumptions on the magnitude of the disutility associated with post-diagnosis psychosocial distress and symptomatic recurrences.

Interpretation

GH is associated with substantial health losses in the United States. Results from this study can be used to compare the burden of GH to other diseases, and it provides inputs that may be used in studies on the health impact and cost-effectiveness of interventions that aim to reduce the burden of GH.

Funding

The Center for Disease Control and Prevention.

Estimation of the Lifetime Quality-Adjusted Life Years (QALYs) Lost Due to Syphilis Acquired in the United States in 2018

BACKGROUND

The purpose of this study was to estimate the health impact of syphilis in the United States in terms of the number of quality-adjusted life years (QALYs) lost attributable to infections in 2018.

METHODS

We developed a Markov model that simulates the natural history and management of syphilis. The model was parameterized by sex and sexual orientation (women who have sex with men, men who have sex with women [MSW], and men who have sex with men [MSM]), and by age at primary infection. We developed a separate decision tree model to quantify health losses due to congenital syphilis. We estimated the average lifetime number of QALYs lost per infection, and the total expected lifetime number of QALYs lost due to syphilis acquired in 2018.

RESULTS

We estimated the average number of discounted lifetime QALYs lost per infection as 0.09 (95% uncertainty interval [UI] .03-.19). The total expected number of QALYs lost due to syphilis acquired in 2018 was 13 349 (5071-31 360). Although per-case loss was the lowest among MSM (0.06), MSM accounted for 47.7% of the overall burden. For each case of congenital syphilis, we estimated 1.79 (1.43-2.16) and 0.06 (.01-.14) QALYs lost in the child and the mother, respectively. We projected 2332 (1871-28 250) and 79 (17-177) QALYs lost for children and mothers, respectively, due to congenital syphilis in 2018.

CONCLUSIONS

Syphilis causes substantial health losses in adults and children. Quantifying these health losses in terms of QALYs can inform cost-effectiveness analyses and can facilitate comparisons of the burden of syphilis to that of other diseases.

The Challenges of Measuring and Valuing Quality of Life in Preschool Children: A Retrospective Review of NICE Appraisals

Health technology assessment agencies evaluate interventions across the lifespan. However, there is no consensus about best-practice methods to measure health-related quality of life (HRQoL) in preschool children (<5 years) and data are often scarce. We reviewed methods used to capture the HRQoL of preschool children in past National Institute for Health and Care Excellence (NICE) appraisals to establish whether there is a need for better methods in this area and if so, to identify priority research areas. We identified past NICE appraisals that included preschool children, examining the methods used to generate utility values and whether committees believed these captured HRQoL adequately. Of the 12 appraisals, most used generic HRQoL measures designed for adults. Measures were usually completed by adult patients or clinical experts. Committees frequently commented on limitations in the HRQoL data. While acknowledging that data collection may be challenging, committees would value evidence based on HRQoL data from parents or guardians collected as part of a clinical trial. We identified several research priorities including the psychometric properties of existing measures; the feasibility and validity of valuation studies; and mapping. Progress in these areas will help ensure that the aspects of HRQoL which matter to children and their families are captured in NICE evaluations.

What's the Cost? Measuring the Economic Impact of Pediatric Sepsis

Sepsis, life-threatening organ dysfunction secondary to infection, hospitalizes nearly 75,000 children each year in the United States. Most children survive sepsis. However, there is increasing recognition of the longer-term consequences of pediatric sepsis hospitalization on both the child and their family, including medical, psychosocial, and financial impacts. Here, we describe family spillover effects (the impact of illness on caregivers) of pediatric sepsis, why measurement of family spillover effects is important, and the ways in which family spillover effects can be measured.

Review of Valuation Methods of Preference-Based Measures of Health for Economic Evaluation in Child and Adolescent Populations: Where are We Now and Where are We Going?

Methods for measuring and valuing health benefits for economic evaluation and health technology assessment in adult populations are well developed. In contrast, methods for assessing interventions for child and adolescent populations lack detailed guidelines, particularly regarding the valuation of health and quality of life in these age groups. This paper critically examines the methodological considerations involved in the valuation of child- and adolescent-specific health-related quality of life by existing preference-based measures. It also describes the methodological choices made in the valuation of existing generic preference-based measures developed with and/or applied in child and adolescent populations: AHUM, AQoL-6D, CHU9D, EQ-5D-Y, HUI2, HUI3, QWB, 16D and 17D. The approaches used to value existing child- and adolescent-specific generic preference-based measures vary considerably. While the choice of whose preferences and which perspective to use is a matter of normative debate and ultimately for decision by reimbursement agencies and policy makers, greater research around these issues would be informative and would enrich these discussions. Research can also inform the other methodological choices required in the valuation of child and adolescent health states. Gaps in research evidence are identified around the impact of the child described in health state valuation exercises undertaken by adults, including the possibility of informed preferences; the appropriateness and acceptability of valuation tasks for adolescents, in particular tasks involving the state 'dead'; anchoring of adolescent preferences; and the generation and use of combined adult and adolescent preferences.

Cost-Effectiveness Analysis in Pediatric Imaging: The Evidence (or Lack Thereof) Thus Far

OBJECTIVE

To systematically review all published cost-effectiveness analyses (CEAs) of imaging technologies in children.

METHODS

We identified all CEAs involving fetal and pediatric imaging included in a publicly available repository of CEAs published since 1976. Information on publication characteristics, methods, costs, quality of life weights, and incremental cost-effectiveness ratios (ICERs) was recorded for each article.

RESULTS

Of 480 diagnostic CEAs, only 10 focused on fetal and pediatric imaging. The 10 studies reported 43 quality of life weights based on previously published adult data (n = 20, 46.5%); pregnant women perspective (n = 11, 25.6%), and treating physician perspective (n = 12, 27.9%). None of the studies elicited quality of life weights from children nor took into consideration the postnatal impact of disease on family's quality of life. All studies used a health care payer perspective without incorporating patients' incurred cost such as loss wages or travel related cost. Of 37 ICERs, 7 (18.9%) were cost saving and 6 (16.2%) were more expensive and less effective. The remaining ICERs ranged from $1,400 per quality-adjusted life-year (MRI versus ultrasound in newborns with moderate risk of occult spinal dysraphism) to $10,000,000 per quality-adjusted life-year (CT versus no imaging in children at low risk for craniosynostosis).

CONCLUSION

There is a striking paucity of cost-effectiveness studies evaluating imaging technologies in children. Existing studies do not incorporate the patient and family perspectives regarding utilities (eg, impact of child's disease on families' quality of life) or cost (eg, loss wages, travel, time off). Future studies should elicit and incorporate the impact of disease on families to better reflect real-world scenarios.

Utility values for childhood obesity interventions: a systematic review and meta-analysis of the evidence for use in economic evaluation

Rigorous estimates of preference-based utilities are important inputs into economic evaluations of childhood obesity interventions, yet no published review currently exists examining utility by weight status in paediatric populations. A comprehensive systematic literature review and meta-analysis was therefore undertaken, pooling data on preference-based health state utilities by weight status in children using a random-effects model. Tests for heterogeneity were performed, and publication bias was assessed. Of 3,434 potentially relevant studies identified, 11 met our eligibility criteria. Estimates of Cohen's d statistic suggested a small effect of weight status on preference-based utilities. Mean utility values were estimated as 0.85 (95% uncertainty interval [UI] 0.84-0.87), 0.83 (95% UI 0.81-0.85), 0.82 (95% UI 0.79-0.84) and 0.83 (95% UI 0.80-0.86) for healthy weight, overweight, obese and overweight/obese states, respectively. Meta-analysis of studies reporting utility values for both healthy weight and overweight/obese participants found a statistically significant weighted mean difference (0.015, 95% UI 0.003-0.026). A small but statistically significant difference was also estimated between healthy weight and overweight participants (0.011, 95% UI 0.004-0.018). Study findings suggest that paediatric-specific benefits of obesity interventions may not be well reflected by available utility measures, potentially underestimating cost-effectiveness if weight loss in childhood/adolescence improves health or well-being.

Impact of publicly available vaccination rates on parental school and child care choice

OBJECTIVE

Several states require schools and child cares to report vaccination rates, yet little is known about the impact of these policies. Our objectives were to assess: (1) predicted impact of vaccination rates on school/child care choice, (2) differences between vaccine hesitant and non-hesitant parents, and (3) differences by child's age.

METHODS

In 2016, a cross-sectional email survey of Colorado mothers with children ≤12 years old assessed value of vaccination rates in the context of school/child care choice. A willingness-to-pay framework measured preference for schools/child cares with different vaccination rates using tradeoff with commute time.

RESULTS

Response rate was 42% (679/1630). Twelve percent of respondents were vaccine hesitant. On a scale where 1 is "not important at all" and 4 is "very important" parents rated the importance of vaccination rates at 3.08. Respondents (including vaccine-hesitant respondents) would accept longer commutes to avoid schools/child cares with lower vaccination rates. Parents of child-care-age children were more likely to consider vaccination rates important.

CONCLUSIONS

This study shows parents highly value vaccination rates in the context of school and child care choice. Both hesitant and non-hesitant parents are willing to accept longer commute times to protect their children from vaccine-preventable diseases.

The impact of influenza on the health related quality of life in China: an EQ-5D survey

BACKGROUND

Influenza causes considerable morbidity and mortality in China, but its impact on the health-related quality of life (HRQoL) has not been previously measured.

METHODS

We conducted a retrospective telephone survey to assess the impact of influenza on the HRQoL among outpatients and inpatients using the EuroQoL EQ-5D-3 L instrument. Participants were individuals with laboratory-confirmed influenza infection registered by the National Influenza-like-illness Surveillance Network in 2013.

RESULTS

We interviewed 839 of 11,098 eligible influenza patients. After excluding those who were unable to complete the HRQoL for the registered influenza episode, 778 patients were included in the analysis. Both outpatients (n = 529) and inpatients (n = 249) most commonly reported problems with pain/discomfort (71.8% of outpatients and 71.9% of inpatients) and anxiety/depression (62.0% of outpatients and 75.1% of inpatients). For individual influenza outpatients, the mean health utility was 0.6142 (SD 0.2006), and the average quality adjusted life days (QALD) loss was 1.62 (SD 1.84) days. The HRQoL of influenza inpatients was worse (mean health utility 0.5851, SD 0.2197; mean QALD loss 3.51 days, SD 4.25) than that of outpatients (p < 0.05). The presence of underlying medical conditions lowered the HRQoL for both outpatients and inpatients (p < 0.05).

CONCLUSIONS

Influenza illness had a substantial impact on HRQoL. QALD loss due to an acute influenza episode in younger children was comparable to that due to enterovirus A71-associated hand, foot and mouth disease. Our findings are key inputs into disease burden estimates and cost-effectiveness evaluations of influenza-related interventions in China.

Economic costs and health-related quality of life for hand, foot and mouth disease (HFMD) patients in China

BACKGROUND

Hand, foot and mouth disease (HFMD) is a common illness in China that mainly affects infants and children. The objective of this study is to assess the economic cost and health-related quality of life associated with HFMD in China.

METHOD

A telephone survey of caregivers were conducted in 31 provinces across China. Caregivers of laboratory-confirmed HFMD patients who were registered in the national HFMD enhanced surveillance database during 2012-2013 were invited to participate in the survey. Total costs included direct medical costs (outpatient care, inpatient care and self-medication), direct non-medical costs (transportation, nutrition, accommodation and nursery), and indirect costs for lost income associated with caregiving. Health utility weights elicited using EuroQol EQ-5D-3L and EQ-Visual Analogue Scale (VAS) were used to calculate associated loss in quality adjusted life years (QALYs).

RESULTS

The subjects comprised 1136 mild outpatients, 1124 mild inpatients, 1170 severe cases and 61 fatal cases. The mean total costs for mild outpatients, mild inpatients, severe cases and fatal cases were $201 (95%CI $187, $215), $1072 (95%CI $999, $1144), $3051 (95%CI $2905, $3197) and $2819 (95%CI $2068, $3571) respectively. The mean QALY losses per HFMD episode for mild outpatients, mild inpatients and severe cases were 3.6 (95%CI 3.4, 3,9), 6.9 (95%CI 6.4, 7.4) and 13.7 (95%CI 12.9, 14.5) per 1000 persons. Cases who were diagnosed with EV-A71 infection and had longer duration of illness were associated with higher total cost and QALY loss.

CONCLUSION

HFMD poses a high economic and health burden in China. Our results provide economic and health utility data for cost-effectiveness analysis for HFMD vaccination in China.