Preferences for health outcomes associated with Group A Streptococcal disease and vaccination

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.

A review of health-related quality of life associated with pneumococcal disease: pooled estimates by age and type of disease

BACKGROUND

Estimates in the research literature on the health-related quality of life (QOL) associated with pneumococcal disease exhibit variation. It complicates the selection of estimates in modeling projects that evaluate the health impact and economic value of the prevention and treatment. This study reviewed the literature and developed pooled QOL estimates associated with pneumococcal disease states.

METHODS

We searched peer-reviewed literature for studies that reported pneumococcal disease-related QOL estimates. For each study, we extracted QOL estimates and categorized by age group and disease state. QOL estimates were converted to quality-adjusted life-years (QALYs). Pooled QALY estimates were calculated using simple average, sample-size weighting and inverse-variance weighting.

RESULTS

From 18 studies, we organized QOL estimates into 20 groups based on age and disease state. We observed the largest within-disease state variations of QALY estimates in meningitis-related disease states compared to other disease states. Across all age-disease state categories, the pooled QALY estimates ranged from 0.39 for meningitis with long-term sequelae among 0- to 18-year-olds, to 1.00 for non-inpatient pneumonia among 0- to 18-year-olds.

CONCLUSIONS

Our results indicated disparities in QOL estimates associated with pneumococcal disease from the literature. Pooled estimates provided a source of consistency that can be used in future modeling efforts.

Estimating the willingness to pay for a quality-adjusted life year in Thailand: does the context of health gain matter?

BACKGROUND

This study aims to elicit the value of the willingness to pay (WTP) for a quality-adjusted life year (QALY) and to examine the factors associated with the WTP for a QALY (WTP/QALY) value under the Thai health care setting.

METHODS

A community-based survey was conducted among 1191 randomly selected respondents. Each respondent was interviewed face-to-face to elicit his/her health state preference in each of three pairs of health conditions: (1) unilateral and bilateral blindness, (2) paraplegia and quadriplegia, and (3) mild and moderate allergies. A visual analog scale (VAS) and time trade off (TTO) were used as the eliciting methods. Subsequently, the respondents were asked about their WTP for the treatment and prevention of each pair of health conditions by using a bidding-game technique.

RESULTS

With regards to treatment, the mean WTP for a QALY value (WTP/QALY(treatment)) estimated by the TTO method ranged from 59,000 to 285,000 baht (16.49 baht = US$1 purchasing power parity [PPP]). In contrast, the mean WTP for a QALY value in terms of prevention (WTP/QALY(prevention)) was significantly lower, ranging from 26,000 to 137,000 baht. Gender, household income, and hypothetical scenarios were also significant factors associated with the WTP/QALY values.

CONCLUSION

The WTP/QALY values elicited in this study were approximately 0.4 to 2 times Thailand's 2008 GDP per capita. These values were in line with previous studies conducted in several different settings. This study's findings clearly support the opinion that a single ceiling threshold should not be used for the resource allocation of all types of interventions.

Parental and societal values for the risks and benefits of childhood combination vaccines

BACKGROUND

New combination vaccines reduce the number of injections needed for immunization. However, possible drawbacks include higher prices, extra doses of vaccine antigens and increased minor adverse events. Our objective was to measure parental and societal values for attributes of childhood combination vaccines.

METHODS

We conducted a discrete choice experiment using an online survey of adults administered by Knowledge Networks. Values were measured for attributes of combination vaccines for a hypothetical child aged 6 months: (1) number of injections, (2) extra dose of hepatitis B vaccine, (3) 20% higher chance of fever, (4) community-level immunization coverage of 2-year-olds of 90% or 80%, and (5) cost per visit. Logistic regression with generalized estimating equations was used to analyze the value of different attributes and generate a marginal willingness-to-pay for a change in attribute level.

RESULTS

The response rate was 64% (N=558). Most respondents were parents (63%) and most respondents agreed that combination vaccines were safe (77%). Respondents were willing to pay $7.68 to avoid an injection (compared to $9.94 when looking at parents only). However, respondents were willing to pay $41.57 to avoid higher risk of fever after one set of immunizations (10% versus 30%) and $65.42 for higher immunization coverage rates. These results were very similar for parents only. There was no significant preference to avoid an extra dose of hepatitis B vaccine.

CONCLUSIONS

Respondents were willing to pay larger amounts to avoid increased risk of minor adverse events and to increase community-level immunization coverage than to avoid injections. These values should be taken into account when determining the risks and benefits of combination vaccines.

Acute rheumatic fever in the Central Anatolia Region of Turkey: a 30-year experience in a single center

The study was carried out in Dr. Sami Ulus Children's Hospital to investigate and to compare the incidence and findings of acute rheumatic fever patients (ARF) seen in the past 30 years. The medical records of 1,115 patients with ARF admitted to Dr. Sami Ulus Children's Hospital Department of Pediatric Cardiology during 1980-2009 were retrospectively analyzed. Twenty-one percent of those patients were admitted between 1980 and 1989, 44.6% between 1990 and 1999, and 34.2% between 2000 and 2009. The highest incidence was detected in the second decade with a rate of 60.0:100,000. Male/female ratio was 1:18. The age of patients ranged between 2 and 15 years. Carditis was detected in 64.7% of patients, arthritis in 59.1%, and chorea in 14.1%. Mitral regurgitation was the most common echocardiographic finding. Heart failure was detected in 13.8%. Recurrent attacks occurred in 8.1% of patients. The median follow-up was 6.8 years (range, 1.2-10.5 years). The prevalence of chronic rheumatic valvular disease was 58%. Mortality rate was 0.8%.

CONCLUSION

Although the incidence of ARF has decreased in the last decade, it still continues to be an important public health problem in Turkish pediatric population.

How do children at special schools and their parents perceive their HRQoL compared to children at open schools?

Background

There has been some debate in the past as to who should determine values for different health states for economic evaluation. The aim of this study was to compare the Health Related Quality of Life (HRQoL) in children attending open schools (OS) and children with disabilities attending a special school (SS) and their parents in Cape Town South Africa.

Methods

The EQ-5D-Y and a proxy version were administered to the children and their parents were requested to fill in the EQ-5D-Y proxy version without consultation with their children on the same day.

Results

A response rate of over 20% resulted in 567 sets of child/adult responses from OS children and 61 responses from SS children. Children with special needs reported more problems in the "Mobility" and "Looking after myself" domains but their scores with regard to "Doing usual activities", "Pain or discomfort" and "Worried, sad or unhappy" were similar to their typically developing counterparts. The mean Visual Analogue Scale (VAS) score of SS children was (88.4, SD18.3, range 40-100) which was not different to the mean score of the OS respondents (87.9, SD16.5, range 5-100).

The association between adult and child scores was fair to moderate in the domains. The correlations in VAS scores between Open Schools children and female care-givers' scores significant but low (r = .33, p < .001) and insignificant between Special School children and adult (r = .16, p = .24).

Discussion

It would appear that children with disabilities do not perceive their HRQoL to be worse than their able bodied counterparts, although they do recognise their limitations in the domains of "Mobility" and "Doing usual activities".

Conclusions

This finding lends weight to the argument that valuation of health states by children affected by these health states should not be included for the purpose of economic analysis as the child's resilience might result in better values for health states and possibly a correspondingly smaller resource allocation. Conversely, if HRQoL is to be used as a clinical outcome, then it is preferable to include the children's values as proxy report does not appear to be highly correlated with the child's own perceptions.