Values for preventing influenza-related morbidity and vaccine adverse events in children

Systematic Review of the Relative Social Value of Child and Adult Health

OBJECTIVES

We aimed to synthesise knowledge on the relative social value of child and adult health.

METHODS

Quantitative and qualitative studies that evaluated the willingness of the public to prioritise treatments for children over adults were included. A search to September 2023 was undertaken. Completeness of reporting was assessed using a checklist derived from Johnston et al. Findings were tabulated by study type (matching/person trade-off, discrete choice experiment, willingness to pay, opinion survey or qualitative). Evidence in favour of children was considered in total, by length or quality of life, methodology and respondent characteristics.

RESULTS

Eighty-eight studies were included; willingness to pay (n = 9), matching/person trade-off (n = 12), discrete choice experiments (n = 29), opinion surveys (n = 22) and qualitative (n = 16), with one study simultaneously included as an opinion survey. From 88 studies, 81 results could be ascertained. Across all studies irrespective of method or other characteristics, 42 findings supported prioritising children, while 12 provided evidence favouring adults in preference to children. The remainder supported equal prioritisation or found diverse or unclear views. Of those studies considering prioritisation within the under 18 years of age group, nine findings favoured older children over younger children (including for life saving interventions), six favoured younger children and five found diverse views.

CONCLUSIONS

The balance of evidence suggests the general public favours prioritising children over adults, but this view was not found across all studies. There are research gaps in understanding the public's views on the value of health gains to very young children and the motivation behind the public's views on the value of child relative to adult health gains.

CLINICAL TRIAL REGISTRATION

The review is registered at PROSPERO number: CRD42021244593. There were two amendments to the protocol: (1) some additional search terms were added to the search strategy prior to screening to ensure coverage and (2) a more formal quality assessment was added to the process at the data extraction stage. This assessment had not been identified at the protocol writing stage.

A Quantitative Framework for Medication Non-Adherence: Integrating Patient Treatment Expectations and Preferences

Introduction

Medication non-adherence remains a significant challenge in healthcare, impacting treatment outcomes and the overall effectiveness of medical interventions. This article introduces a novel approach to understanding and predicting medication non-adherence by integrating patient beliefs, efficacy expectations, and perceived costs. Existing theoretical models often fall short in quantifying the impact of barrier removal on medication adherence and struggle to address cases where patients consciously choose not to follow prescribed medication regimens. In response to these limitations, this study presents an empirical framework that seeks to provide a quantifiable model for both individual and population-level prediction of non-adherence under different scenarios.

Methods

We present an empirical framework that includes a health production function, specifically applied to antihypertensive medications nonadherence. Data collection involved a pilot study that utilized a double-bound contingent-belief (DBCB) questionnaire. Through this questionnaire, participants could express how efficacy and side effects were affected by controlled levels of non-adherence, allowing for the estimation of sensitivity in health outcomes and costs.

Results

Parameters derived from the DBCB questionnaire revealed that on average, patients with hypertension anticipated that treatment efficacy was less sensitive to non-adherence than side effects. Our derived health production function suggests that patients may strategically manage adherence to minimize side effects, without compromising efficacy. Patients' inclination to manage medication intake is closely linked to the relative importance they assign to treatment efficacy and side effects. Model outcomes indicate that patients opt for full adherence when efficacy outweighs side effects. Our findings also indicated an association between income and patient expectations regarding the health of antihypertensive medications.

Conclusion

Our framework represents a pioneering effort to quantitatively link non-adherence to patient preferences. Preliminary results from our pilot study of patients with hypertension suggest that the framework offers a viable alternative for evaluating the potential impact of interventions on treatment adherence.

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.

Influence of the child's perceived general health on the primary caregiver's health status

BACKGROUND

In estimating the impact of an intervention, ignoring the effect of improving the health of one member of the caregiver/child dyad on the Health Related Quality of Life (HRQoL) of the other member may lead to an underestimation of the utility gained. This may be particularly true for infants/young children and their caregivers. The aim of this study was to quantify the interaction between the child's perceived general health as assessed by the newly developed Toddler and Infant Questionnaire (TANDI) on the reporting of the caregiver's own HRQoL as assessed by the EQ-5D-3 L.

METHODS

A sample of 187 caregivers participated. A total of 60 caregivers of acutely-ill (AI) and 60 caregivers of chronically-ill (CI) children were recruited from a children's hospital. The 67 caregivers of general population (GP) children were recruited at a pre-school. Each caregiver completed the proxy rating of their child's HRQoL on the TANDI (The TANDI is an experimental HRQoL instrument, modelled on the EQ-5D-Y proxy, for children aged 1-36 months), which comprises of six dimensions of health and a rating of general health on a Visual Analogue Scale (VAS). The caregiver completed the EQ-5D-3 L, a self-report measure of their own HRQoL. Forward stepwise regression models were developed with 1) the VAS score of the caregiver and 2) the VAS score of the child as dependent variables. The independent variables for the caregiver included dummy variables for the presence or absence of problems on the EQ-5D-3 L and the VAS score of the child. The independent variables for the child included dummy variables for each TANDI dimension and the VAS of the caregiver.

RESULTS

The TANDI results indicated that in five of the six dimensions AI children had more problems than the other two groups and the GP children were reported to have a significantly higher VAS than the other two groups. The child's VAS was significantly correlated with the caregiver's VAS in all groups, but most strongly in the AI group. The preference based scores (using the UK TTO tariff) were only correlated in the AI group. The inclusion of the child's VAS increased the variance accounted for 11% of the VAS score of the caregiver. Anxiety and depression was the only dimension which accounted for more variance (18%). Similarly the perceived health state, VAS of the caregiver accounted for 14% of the variance in the child's VAS, second only to problems with play (25%).

CONCLUSION

There does indeed appear to be a strong relationship between the VAS scores of the children and their caregivers. The perceived general health of the child influences the caregivers reporting of their general health, more than their own report of experiencing pain or discomfort or problems with mobility. Thus, improving the HRQoL of the very young child may improve the caregiver's HRQoL as well. Conversely, if the caregiver has a lower perceived HRQoL this may result in a decrement in the reported VAS of the child, independent of the presence or absence of problems in the different dimensions. This improvement is not currently captured by Cost Utility Analysis (CUA). It is recommended that future research investigates this effect with regards to CUA calculations.

Cost-effectiveness of Strategies for Offering Influenza Vaccine in the Pediatric Emergency Department

IMPORTANCE

Influenza is a significant public health burden, causing morbidity and mortality in children, yet vaccination rates remain low. Vaccination in the pediatric emergency department (PED) setting may be beneficial but, to date, has not been proven to be cost-effective.

OBJECTIVE

To compare the cost-effectiveness of 4 strategies for PED-based influenza vaccine: offering vaccine to all patients, only to patients younger than 5 years, only to high-risk patients (all ages), or to no patients.

DESIGN, SETTING, AND PARTICIPANTS

Using commercial decision analysis software, a cost-effectiveness analysis was performed from January 1, 2016, to June 1, 2017, to compare influenza vaccine strategies at a tertiary, urban, freestanding PED with an estimated 60 000 visits per year among a hypothetical cohort of children visiting the above PED during influenza season. Sensitivity analyses estimated the effect of uncertainties across a variety of input variables (eg, influenza prevalence, vaccine price and effectiveness, and costs of complications).

MAIN OUTCOMES AND MEASURES

The primary outcomes were cost and incremental cost-effectiveness ratio in dollars per influenza case averted. Secondary outcomes included total societal costs, hospitalizations and deaths averted, and quality-adjusted life-years gained.

RESULTS

Offering influenza vaccine to all eligible patients has the lowest cost, at $114.45 (95% CI, $55.48-$245.45) per case of influenza averted. This strategy saves $33.51 (95% CI, $18-$62) per case averted compared with no vaccination, and averages 27 fewer cases of influenza per 1000 patients. Offering vaccine to all patients resulted in 0.72 days (95% CI, 0.18-1.78 days) of quality-adjusted life-years lost, whereas offering to none resulted in 0.91 days (95% CI, 0.25-2.2 days) of quality-adjusted life-years lost. In sensitivity analyses, this strategy remains robustly cost-effective across a wide range of assumptions. In addition to being the most cost-effective strategy regardless of age or risk status, routine vaccination in the PED results in a net societal monetary benefit under many circumstances. In Monte Carlo analysis, offering vaccine to all patients was superior to other strategies in at least 99.8% of cases.

CONCLUSIONS AND RELEVANCE

Although few PEDs routinely offer influenza vaccination, doing so appears to be cost-effective, with the potential to significantly reduce the economic (and patient) burden of pediatric influenza.

Cost effectiveness of a targeted age-based West Nile virus vaccination program

BACKGROUND

West Nile virus (WNV) is the leading cause of domestically-acquired arboviral disease in the United States. Several WNV vaccines are in various stages of development. We estimate the cost-effectiveness of WNV vaccination programs targeting groups at increased risk for severe WNV disease.

METHODS

We used a mathematical model to estimate costs and health outcomes of vaccination with WNV vaccine compared to no vaccination among seven cohorts, spaced at 10year intervals from ages 10 to 70years, each followed until 90-years-old. U.S. surveillance data were used to estimate WNV neuroinvasive disease incidence. Data for WNV seroprevalence, acute and long-term care costs of WNV disease patients, quality-adjusted life-years (QALYs), and vaccine characteristics were obtained from published reports. We assumed vaccine efficacy to either last lifelong or for 10years with booster doses given every 10years.

RESULTS

There was a statistically significant difference in cost-effectiveness ratios across cohorts in both models and all outcomes assessed (Kruskal-Wallis test p<0.0001). The 60-year-cohort had a mean cost per neuroinvasive disease case prevented of $664,000 and disability averted of $1,421,000 in lifelong model and $882,000 and $1,887,000, respectively in 10-year immunity model; these costs were statistically significantly lower than costs for other cohorts (p<0.0001). Vaccinating 70-year-olds had the lowest cost per death averted in both models at around $4.7 million (95%CI $2-$8 million). Cost per disease case averted was lowest among 40- and 50-year-old cohorts and cost per QALY saved lowest among 60-year cohorts in lifelong immunity model. The models were most sensitive to disease incidence, vaccine cost, and proportion of persons developing disease among infected.

CONCLUSIONS

Age-based WNV vaccination program targeting those at higher risk for severe disease is more cost-effective than universal vaccination. Annual variation in WNV disease incidence, QALY weights, and vaccine costs impact the cost effectiveness ratios.

Cost-Effectiveness of Quadrivalent versus Trivalent Influenza Vaccine in the United States

BACKGROUND

Designed to overcome influenza B mismatch, new quadrivalent influenza vaccines (QIVs) contain one additional B strain compared with trivalent influenza vaccines (TIVs).

OBJECTIVE

To examine the expected public health impact, budget impact, and incremental cost-effectiveness of QIV versus TIV in the United States.

METHODS

A dynamic transmission model was used to predict the annual incidence of influenza over the 20-year-period of 2014 to 2034 under either a TIV program or a QIV program. A decision tree model was interfaced with the transmission model to estimate the public health impact and the cost-effectiveness of replacing TIV with QIV from a societal perspective. Our models were informed by published data from the United States on influenza complication probabilities and relevant costs. The incremental vaccine price of QIV as compared with that of TIV was set at US $5.40 per dose.

RESULTS

Over the next 20 years, replacing TIV with QIV may reduce the number of influenza B cases by 27.2% (16.0 million cases), resulting in the prevention of 137,600 hospitalizations and 16,100 deaths and a gain of 212,000 quality-adjusted life-years (QALYs). The net societal budget impact would be US $5.8 billion and the incremental cost-effectiveness ratio US $27,411/QALY gained. In the probabilistic sensitivity analysis, 100% and 96.5% of the simulations fell below US $100,000/QALY and US $50,000/QALY, respectively.

CONCLUSIONS

Introducing QIV into the US immunization program may prevent a substantial number of hospitalizations and deaths. QIV is also expected to be a cost-effective alternative option to TIV.

Cost-effectiveness of seasonal quadrivalent versus trivalent influenza vaccination in the United States: A dynamic transmission modeling approach

Trivalent inactivated influenza vaccines (IIV3s) protect against 2 A strains and one B lineage; quadrivalent versions (IIV4s) protect against an additional B lineage. The objective was to assess projected health and economic outcomes associated with IIV4 versus IIV3 for preventing seasonal influenza in the US. A cost-effectiveness model was developed to interact with a dynamic transmission model. The transmission model tracked vaccination, influenza cases, infection-spreading interactions, and recovery over 10 y (2012–2022). The cost-effectiveness model estimated influenza-related complications, direct and indirect costs (2013–2014 US$), health outcomes, and cost-effectiveness. Inputs were taken from published/public sources or estimated using regression or calibration. Outcomes were discounted at 3% per year. Scenario analyses tested the reliability of the results. Seasonal vaccination with IIV4 versus IIV3 is predicted to reduce annual influenza cases by 1,973,849 (discounted; 2,325,644 undiscounted), resulting in 12–13% fewer cases and influenza-related complications and deaths. These reductions are predicted to translate into 18,485 more quality-adjusted life years (QALYs) accrued annually for IIV4 versus IIV3. Increased vaccine-related costs ($599 million; 5.7%) are predicted to be more than offset by reduced influenza treatment costs ($699 million; 12.2%), resulting in direct medical cost saving annually ($100 million; 0.6%). Including indirect costs, savings with IIV4 are predicted to be $7.1 billion (5.6%). Scenario analyses predict IIV4 to be cost-saving in all scenarios tested apart from low infectivity, where IIV4 is predicted to be cost-effective. In summary, seasonal influenza vaccination in the US with IIV4 versus IIV3 is predicted to improve health outcomes and reduce costs.

Cost-effectiveness of seasonal inactivated influenza vaccination among pregnant women

OBJECTIVE

To evaluate the cost-effectiveness of seasonal inactivated influenza vaccination among pregnant women using data from three recent influenza seasons in the United States.

DESIGN, SETTING, AND PARTICIPANTS

We developed a decision-analytic model following a cohort of 5.2 million pregnant women and their infants aged <6 months to evaluate the cost-effectiveness of vaccinating women against seasonal influenza during pregnancy from a societal perspective. The main outcome measures were quality-adjusted life-year (QALY) gained and cost-effectiveness ratios. Data sources included surveillance data, epidemiological studies, and published vaccine cost data. Sensitivity analyses were also performed. All costs and outcomes were discounted at 3% annually.

MAIN OUTCOME MEASURES

Total costs (direct and indirect), effects (QALY gains, averted case numbers), and incremental cost-effectiveness of seasonal inactivated influenza vaccination among pregnant women (cost per QALY gained).

RESULTS

Using a recent benchmark of 52.2% vaccination coverage among pregnant women, we studied a hypothetical cohort of 2,753,015 vaccinated pregnant women. With an estimated vaccine effectiveness of 73% among pregnant women and 63% among infants <6 months, QALY gains for each season were 305 (2010-2011), 123 (2011-2012), and 610 (2012-2013). Compared with no vaccination, seasonal influenza vaccination during pregnancy was cost-saving when using data from the 2010-2011 and 2012-2013 influenza seasons. The cost-effectiveness ratio was greater than $100,000/QALY with the 2011-2012 influenza season data, when CDC reported a low attack rate compared to other recent seasons.

CONCLUSIONS

Influenza vaccination for pregnant women can reduce morbidity from influenza in both pregnant women and their infants aged <6 months. Seasonal influenza vaccination during pregnancy is cost-saving during moderate to severe influenza seasons.

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

BACKGROUND

Cost-effectiveness analysis of pediatric vaccines for infectious diseases often requires quality-of-life (utility) weights.

OBJECTIVE

To investigate how utility weights have been elicited and used in this context.

METHODS

A systematic review was conducted of studies published between January 1990 and July 2013 that elicited or used utility weights in cost-effectiveness analyses of vaccines for pediatric populations. The review focused on vaccines for 17 infectious diseases and is presented following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology.

RESULTS

A total of 6410 titles and abstracts and 225 full-text articles were reviewed. Of those selected for inclusion (n = 101), 15 articles described the elicitation of utility weights and 86 described economic modeling studies using utilities. Various methods were used to generate utilities, including time trade-off, contingent valuation, and willingness to pay, as well as a preference-based measure with associated value sets, such as the EuroQol five-dimensional questionnaire or the Health Utilities Index. In modeling studies, the source of utilities used was often unclear, poorly reported, or based on weak underlying evidence. We found no articles that reported on the elicitation or use of utilities in diphtheria, polio, or tetanus.

CONCLUSIONS

The scarcity of appropriate utility weights for vaccine-preventable infectious diseases in children and a lack of standardization in their use in economic assessments limit the ability to accurately assess the benefits associated with interventions to prevent infectious diseases. This is an issue that should be of concern to those making decisions regarding the prevention and treatment of infectious childhood illnesses.

Seasonal influenza vaccination for children in Thailand: a cost-effectiveness analysis

BACKGROUND

Seasonal influenza is a major cause of mortality worldwide. Routine immunization of children has the potential to reduce this mortality through both direct and indirect protection, but has not been adopted by any low- or middle-income countries. We developed a framework to evaluate the cost-effectiveness of influenza vaccination policies in developing countries and used it to consider annual vaccination of school- and preschool-aged children with either trivalent inactivated influenza vaccine (TIV) or trivalent live-attenuated influenza vaccine (LAIV) in Thailand. We also compared these approaches with a policy of expanding TIV coverage in the elderly.

METHODS AND FINDINGS

We developed an age-structured model to evaluate the cost-effectiveness of eight vaccination policies parameterized using country-level data from Thailand. For policies using LAIV, we considered five different age groups of children to vaccinate. We adopted a Bayesian evidence-synthesis framework, expressing uncertainty in parameters through probability distributions derived by fitting the model to prospectively collected laboratory-confirmed influenza data from 2005-2009, by meta-analysis of clinical trial data, and by using prior probability distributions derived from literature review and elicitation of expert opinion. We performed sensitivity analyses using alternative assumptions about prior immunity, contact patterns between age groups, the proportion of infections that are symptomatic, cost per unit vaccine, and vaccine effectiveness. Vaccination of children with LAIV was found to be highly cost-effective, with incremental cost-effectiveness ratios between about 2,000 and 5,000 international dollars per disability-adjusted life year averted, and was consistently preferred to TIV-based policies. These findings were robust to extensive sensitivity analyses. The optimal age group to vaccinate with LAIV, however, was sensitive both to the willingness to pay for health benefits and to assumptions about contact patterns between age groups.

CONCLUSIONS

Vaccinating school-aged children with LAIV is likely to be cost-effective in Thailand in the short term, though the long-term consequences of such a policy cannot be reliably predicted given current knowledge of influenza epidemiology and immunology. Our work provides a coherent framework that can be used for similar analyses in other low- and middle-income countries.

Methodological and applied concerns surrounding age-related weighting within health economic evaluation

Economic evaluations that measure the benefits of health interventions in terms of units of health gain inevitably require decision-makers to make judgments about the 'value for money' of those health gains. Decision-making bodies have also commonly returned to the position that a unit of health gain, such as an additional quality-adjusted life year, is of equal value regardless of the characteristics of the recipient. This paper focuses on whether and how health gains in economic evaluation should be differentially weighted by age of recipient. The paper presents a structured overview of evidence from the revealed preference and stated preference literature in this area. It discusses a number of methodological issues raised by differential weighting of health gains by age of recipient. These include identifying appropriate samples for the derivation of age-related weights, methodological issues surrounding the application of the quality-adjusted life year measure, the relative merits of alternative valuation techniques for weighting exercises, the impact of context and design effects on derived values and operational concerns surrounding the application of age-related weights within economic evaluation. The paper ends with pointers for potential future research in this area.

Valuing human leptospirosis prevention using the opportunity cost of labor

Leptospirosis is a serious public health concern in the Philippines, not only because of its increasing incidence rate, but also because of its significant health and economic impacts. Despite its relatively high seroprevalence, knowledge on the economic burden of disease, particularly on the value that the society places on disease prevention remains limited. Obtaining such information is important within the context of public health policy. This study was conducted in Metro Manila to determine the economic burden of leptospirosis, by asking respondents about their willingness to contribute to labor (WTCL) for the prevention of leptospirosis. The respondents pledged an average labor contribution of 10.66 h/month. The average WTCL corresponded to a monetary value of US$4.01 per month when valued using the opportunity cost of labor (leisure rate of time). From the monetized labor contribution, the total economic value of preventing leptospirosis was estimated at US$124.97 million per annum, which represents 1.13% of Metro Manila's gross domestic product (GDP). Estimates from a Tobit regression model identified the respondents' knowledge regarding leptospirosis, the susceptibility of their homes to flooding, and the proximity of their homes to sewers as significant factors to consider when developing resource contribution programs for leptospirosis prevention. More efforts need to be made in developing community level preventive programs, and in improving public's knowledge and awareness about leptospirosis.

Using a discrete choice experiment to elicit time trade-off and willingness-to-pay amounts for influenza health-related quality of life at different ages

BACKGROUND

Recent research suggests that values for health-related quality of life may vary with the age of the patient. Traditional health state valuation questions and discrete choice experiments are two approaches that could be used to value health.

OBJECTIVE

To measure whether public values for health vary with the age of the affected individual.

METHODS

A discrete choice experiment was administered via the Internet in December 2007 to measure preferences for different attributes of influenza-related health-related quality of life: age of hypothetical affected individual (range 1-85 years), length of episode (days of illness), severity of illness (workdays lost) and time trade-off or willingness-to-pay amounts. Each respondent answered identical choice questions for a hypothetical family member and for himself/herself. Data on sociodemographic characteristics and influenza illness experience were also collected. Respondents were US adults randomly sampled from an Internet survey panel (n = 1,012). The relative value of attributes was estimated using generalized estimating equations and controlling for sociodemographic characteristics and illness experience. Marginal time traded and marginal willingness to pay using discrete choice and traditional time trade-off or willingness-to-pay questions were compared.

RESULTS

Respondents preferred shorter influenza episodes but did not significantly prefer fewer workdays lost if episode length was held constant. Respondents were more likely to choose to avert uncomplicated illness in children and less likely to choose to avert uncomplicated illness in working-age adults. Marginal time trade-off and willingness-to-pay amounts elicited using discrete choice questions were larger than those elicited using direct valuation questions.

CONCLUSIONS

Approaches that assume values for health-related quality of life do not vary with the age of a patient may bias economic analyses that use these values. If patient age could affect valuations, then age should be included in the valuation exercise. Additional research should evaluate the effect of patient age on values for other conditions.

Impact of influenza on health-related quality of life among confirmed (H1N1)2009 patients

BACKGROUND

We aimed to assess the changes in health-related quality of life (HRQL) in patients with confirmed diagnosis of influenza (H1N1)2009, and to estimate the individual and societal loss of quality-adjusted life years (QALYs) caused by the pandemic.

METHODS AND RESULTS

Longitudinal study of patients recruited at major hospitals and primary care centers in Spain. Patients reported their HRQL (EQ-5D) during their influenza episode and seven days prior to it. A subsample was monitored to evaluate HRQL after recovery. HRQL loss was estimated as the difference between EQ-5D prior to the influenza episode and during it. Individual QALY loss (disutility multiplied by the duration of the influenza episode in days) for confirmed cases was calculated and used to estimate the societal loss in Spain (with the official estimations). A total of 432 inpatients and 563 outpatients were included, of whom 145 and 184, respectively, were followed up. Baseline mean HRQL loss was 0.58 (95% CI, 0.53-0.63) for inpatients and 0.43 (95% CI, 0.40-0.46) for outpatients. The majority of the 145 inpatients and 184 outpatients who were followed up regained initial HRQL levels, presenting a mean difference of 0.01 between the EQ-5D score prior to and after the influenza episode. Individual QALY losses for inpatients (0.031, 95% CI, 0.025-0.037) were higher than for outpatients (0.009, 95% CI, 0.007-0.011), while societal QALY losses were reversed: 94 years for inpatients and 6,778 years for outpatients. For fatal cases (an official number of 318), we estimated a QALY loss of 11,981.

CONCLUSIONS

The influenza (H1N1)2009 pandemic had a significant but temporary impact on the HRQL of the majority of confirmed in- and outpatients. The societal impact of the influenza pandemic in Spain was estimated to be higher than other acute conditions. These results provide useful data for future cost-utility analyses.

Evidence of spillover of illness among household members: EQ-5D scores from a US sample

BACKGROUND/OBJECTIVES

The effects of illness extend beyond the individual to caregivers and family members. This study identified evidence of spillover of illness onto household members' health-related quality of life.

METHODS

Medical Expenditures Panel Survey (MEPS) data from 2000-2003 were analyzed using multivariable regression to identify spillover of household members' chronic conditions onto individuals' health-related quality of life as measured by the EuroQol-5D (EQ-5D) score (N = 24,188). Spillover was assessed by disease category, timing of occurrence (preexisting or new conditions), and age of the household member (adult or child).

RESULTS

Controlling for an individual's own health conditions and other known predictors of EQ-5D scores, the authors found that the odds of an individual reporting full health (an EQ-5D score of 1.0, relative to <1.0) were lower with the presence of existing mental (odds ratio 0.71; 95% confidence interval, 0.64-0.79), respiratory (0.85; 0.75-0.97), and musculoskeletal (0.83; 0.75-0.93) conditions among adults and with mental (0.72; 0.62-0.82) and respiratory (0.80; 0.81-0.96) conditions among children in the household. The odds of an individual reporting full health were also lower for newly occurring chronic conditions in the household, including adults' mental (0.79; 0.65-0.97), nervous/sensory system (0.76; 0.61-0.96), and musculoskeletal (0.78; 0.65-0.95) conditions and children's mental conditions (0.64; 0.48-0.86). EQ-5D dimensions may be unsuited to fully capture spillover utility among household members, and MEPS lacks condition severity and caregiver status among household members.

CONCLUSIONS

Evidence from a US sample suggests that individuals who live with chronically ill household members have lower EQ-5D scores than those who live either alone or with healthy household members. Averting spillover effects may confer substantial additional benefit at the population level for interventions that prevent or alleviate conditions that incur such effects.

Autism spectrum disorders: a review of measures for clinical, health services and cost-effectiveness applications

Autism spectrum disorders (ASDs) are characterized by impairments in social interaction, communication and behavioral functioning that can affect the health-related quality-of-life outcomes of the affected child and the family. ASDs have increased in prevalence, leading to a demand for improved understanding of the comparative effectiveness of different pharmacologic, behavioral, medical and alternative treatments for children as well as systems for providing services. This review describes outcome instruments that can be used for clinical, health services and cost-effectiveness applications. There is a pressing need to identify the most appropriate instruments for measuring health-related quality-of-life outcomes in this population. Studies evaluating the cost-effectiveness of interventions or treatments for children with ASDs using the cost per quality-adjusted life year metric are lacking. Researchers have the potential to contribute greatly to the field of autism by quantifying outcomes that can inform optimal treatment strategies.

Assessing households' willingness to pay for an immediate pandemic influenza vaccination programme

AIMS

This study sought to contribute to the existing literature on pandemic influenza vaccination studies by providing additional evidences of households' willingness to pay (WTP) for protection against influenza during a pandemic situation from North America.

METHODS

A standard dichotomous-choice contingent valuation survey was designed and completed in a sample of 306 individuals living in the Greater Toronto Area, Ontario, Canada.

RESULTS

This study shows that, on average, households are willing to pay $417.35 for immediate pandemic influenza (H1N1) vaccination. Results show that the vaccine price, age, gender, occupation, organisation, annual family income, receiving annual flu shot, having additional insurance, having someone with a serious illness in the house, knowledge about pandemics, trusting official information on pandemics, supporting government expenditure, and rating government pandemic planning have significant effects on the decision to accept the vaccine bids.

CONCLUSIONS

The results reconfirm the findings of similar studies that influenza vaccine programmes are highly cost-effective despite the high programme cost, because people's WTP (benefits) for this programme is much higher than the actual costs. Pandemic influenza vaccination programmes should consider the demographic and economic status of the target population as such characteristics have significant impacts on the benefits that people place on such programmes.

Cost-effectiveness of oseltamivir treatment for children with uncomplicated seasonal influenza

OBJECTIVE

To evaluate the cost-effectiveness of oseltamivir treatment for seasonal influenza in children and consider the impact of oseltamivir resistance on these findings.

STUDY DESIGN

We developed a model to evaluate 1-year clinical and economic outcomes associated with 3 outpatient management strategies for unvaccinated children with influenza-like-illness: no antiviral treatment; diagnostic testing and oseltamivir treatment when positive; and empiric oseltamivir treatment. The model depicted a hypothetical non-pandemic influenza season with a 29% level of oseltamivir resistance in circulating viruses, and 14% to 54% probability of seasonal influenza with influenza-like-illness. Strategies were compared with incremental cost-effectiveness ratios.

RESULTS

In our primary analysis, empiric oseltamivir treatment consistently produced the greatest benefit. The incremental cost-effectiveness of this alternative, compared with testing and treating, was <$100,000 per quality-adjusted life year gained in all age groups except the oldest. The testing strategy was consistently more effective compared with no treatment and cost between $25,900 and $71,200 per quality-adjusted life year gained, depending on age. Results were sensitive to the prevalence of oseltamivir resistance in circulating viruses.

CONCLUSION

Empiric oseltamivir treatment of seasonal influenza is associated with favorable cost-effectiveness ratios, particularly in children aged 1 to <12 years, but ratios are highly dependent on the prevalence of oseltamivir resistance among circulating influenza viruses.

Community-based values for 2009 pandemic influenza A H1N1 illnesses and vaccination-related adverse events

OBJECTIVE

To evaluate community-based values for avoiding pandemic influenza (A) H1N1 (pH1N1) illness and vaccination-related adverse events in adults and children.

METHODS

Adult community members were randomly selected from a nationally representative research panel to complete an internet survey (response rate = 65%; n = 718). Respondents answered a series of time trade-off questions to value four hypothetical health state scenarios for varying ages (1, 8, 35, or 70 years): uncomplicated pH1N1 illness, pH1N1 illness-related hospitalization, severe allergic reaction to the pH1N1 vaccine, and Guillain-Barré syndrome. We calculated descriptive statistics for time trade-off amounts and derived quality adjusted life year losses for these events. Multivariate regression analyses evaluated the effect of scenario age, as well as respondent socio-demographic and health characteristics on time trade-off amounts.

RESULTS

Respondents were willing to trade more time to avoid the more severe outcomes, hospitalization and Guillain-Barré syndrome. In our adjusted and unadjusted analyses, age of the patient in the scenario was significantly associated with time trade-off amounts (p-value<0.05), with respondents willing to trade more time to prevent outcomes in children versus adults. Persons who had received the pH1N1 vaccination were willing to trade significantly more time to avoid hospitalization, severe allergic reaction, and Guillain-Barré syndrome, controlling for other variables in adjusted analyses.(p-value<0.05)

CONCLUSIONS

Community members placed the highest value on preventing outcomes in children, compared with adults, and the time trade-off values reported were consistent with the severity of the outcomes presented. Considering these public values along with other decision-making factors may help policy makers improve the allocation of pandemic vaccine resources.

Serious adverse events following receipt of trivalent inactivated influenza vaccine in Korea, 2003-2010

BACKGROUND

Vaccination is very important for the control and prevention of influenza, yet no vaccine is perfectly safe. Little is known, however, about influenza vaccination-associated serious adverse events following immunization (AEFI). This study aimed to identify background information on influenza vaccination-related serious AEFI in Korea.

METHODS

Retrospective review of data from Korea National Vaccine Injury Compensation Program from 2003 to 2010.

RESULTS

Distribution of approximately 75 million doses of influenza vaccine by end of 2010 gave rise to 42 potentially serious AEFI. In all, nine Guillain-Barré syndrome, eighteen other neurologic events, eight local events, and seven miscellaneous events were included. 62% of these events were identified to have unlike causal association with the vaccine. The reporting rate of serious AEFI ranged from 0.006 to 0.07 cases per 100,000 distributed doses of the vaccine.

CONCLUSION

GBS was the most common influenza vaccination-related serious AEFI. Enhancing post-vaccination GBS surveillance may increase public confidence in future routine and pandemic influenza vaccination.

Cost-effectiveness of 2009 pandemic influenza A(H1N1) vaccination in the United States

BACKGROUND

Pandemic influenza A(H1N1) (pH1N1) was first identified in North America in April 2009. Vaccination against pH1N1 commenced in the U.S. in October 2009 and continued through January 2010. The objective of this study was to evaluate the cost-effectiveness of pH1N1 vaccination.

METHODOLOGY

A computer simulation model was developed to predict costs and health outcomes for a pH1N1 vaccination program using inactivated vaccine compared to no vaccination. Probabilities, costs and quality-of-life weights were derived from emerging primary data on pH1N1 infections in the US, published and unpublished data for seasonal and pH1N1 illnesses, supplemented by expert opinion. The modeled target population included hypothetical cohorts of persons aged 6 months and older stratified by age and risk. The analysis used a one-year time horizon for most endpoints but also includes longer-term costs and consequences of long-term sequelae deaths. A societal perspective was used. Indirect effects (i.e., herd effects) were not included in the primary analysis. The main endpoint was the incremental cost-effectiveness ratio in dollars per quality-adjusted life year (QALY) gained. Sensitivity analyses were conducted.

RESULTS

For vaccination initiated prior to the outbreak, pH1N1 vaccination was cost-saving for persons 6 months to 64 years under many assumptions. For those without high risk conditions, incremental cost-effectiveness ratios ranged from $8,000-$52,000/QALY depending on age and risk status. Results were sensitive to the number of vaccine doses needed, costs of vaccination, illness rates, and timing of vaccine delivery.

CONCLUSIONS

Vaccination for pH1N1 for children and working-age adults is cost-effective compared to other preventive health interventions under a wide range of scenarios. The economic evidence was consistent with target recommendations that were in place for pH1N1 vaccination. We also found that the delays in vaccine availability had a substantial impact on the cost-effectiveness of vaccination.

Ordering errors, objections and invariance in utility survey responses: a framework for understanding who, why and what to do

BACKGROUND

Utilities are the quantification of the perceived quality of life associated with any health state. They are used to calculate QALYs, the outcome measure in cost-utility analysis. Generally measured through surveys of individuals, utilities often contain apparent or unapparent errors that can bias resulting values and QALYs calculated from these values.

OBJECTIVE

The aim of this study was to improve direct health utility elicitation methodology through the identification of the types of survey responses that indicate errors and objections, and the reasons underlying them.

METHODS

We conducted a systematic review of the medical (PubMed), economics (EconLit) and psychology (PsycINFO) literature from 1975 through June 2010 for articles describing the types and frequency of errors and objections in directly elicited utility survey responses, and strategies to address these responses. Primary data were collected through an internet-based utility survey (standard gamble) of community members to identify responses that indicate error or objections. A qualitative telephone survey was conducted among a subset of respondents with these types of responses using an open-ended protocol to elicit rationales for them.

RESULTS

A total of 11 papers specifically devoted to errors, objections and invariance in utility responses have been published since the mid-1990s. Error/objection responses can be broadly categorized into ordering errors (which include illogical and inconsistent responses) and objections/invariance (which include missing data, protest responses and refusals to trade time or risk in utility questions). Reported frequencies of respondents making ordering errors ranged from 5% to 100%, and up to 35% of respondents have been reported as objecting to the survey or task in some manner. Changes in the design, administration and analysis of surveys can address these potentially problematic responses. Survey data (n = 398) showed that individuals who provided invariant responses (n = 26) reported the lowest level of difficulty with the survey and often identified as religious (23% of invariant responders found the survey difficult vs 63% of all responders, and 77% of invariant responders identified as religious compared with 56% of entire sample; p < 0.05 for both). Respondents who provided illogical responses (n = 50) were less likely to be college educated (56% of illogical responders vs 73% of entire sample; p < 0.05), and less likely to be confident in their responses (62% vs 75% of entire sample; p < 0.05). Qualitative interviews (n = 42) following the survey revealed that the majority of ordering errors were a result of confusion, lack of attention or difficulty in responding to the survey on the part of the respondent, while invariant responses were often considered and thoughtful reactions to the premise of valuing health using the standard gamble task.

CONCLUSIONS

Rationales for error/objection responses include difficulty in articulating preferences or misunderstanding with a complex survey task, and also thoughtful and considered protestations to the task. Mechanisms to correct unintentional errors may be useful, but cannot address intentional responses to elements of the measurement task. Identification and analysis of the prevalence of errors and objections in responses in utility data sets are essential to understanding the accuracy and precision of utility estimates and analyses that depend thereon.

Influence of timing of seasonal influenza vaccination on effectiveness and cost-effectiveness in pregnancy

The purpose of this review was to estimate the impact of timing of seasonal influenza vaccination during pregnancy on health and economic outcomes. Cost-effectiveness analysis with a dynamic model of the US population of pregnant women and infants who were <6 months incorporated seasonal variation in influenza incidence. Compared with no vaccination, seasonal influenza vaccination in pregnancy costs $70,089 per quality-adjusted life year. Most of the benefit for infants was limited to those whose mothers were vaccinated within the first 4 weeks of vaccine availability. Once all women who were pregnant at the time of vaccine availability were vaccinated, vaccination of newly pregnant women had benefits for mothers but not infants. Delay of vaccination beyond November reduced both effectiveness and cost-effectiveness. The greatest population benefit from seasonal influenza vaccination in pregnancy was realized if pregnant women were vaccinated as soon as possible after trivalent inactivated influenza vaccine became available. Efforts to increase vaccine rates should be concentrated early in the influenza season.

The Vaccine Safety Datalink: a model for monitoring immunization safety

The Vaccine Safety Datalink (VSD) project is a collaborative project between the Centers for Disease Control and Prevention and 8 managed care organizations (MCOs) in the United States. Established in 1990 to conduct postmarketing evaluations of vaccine safety, the project has created an infrastructure that allows for high-quality research and surveillance. The 8 participating MCOs comprise a large population of 8.8 million members annually (3% of the US population), which enables researchers to conduct studies that assess adverse events after immunization. Each MCO prepares computerized data files by using a standardized data dictionary containing demographic and medical information on its members, such as age and gender, health plan enrollment, vaccinations, hospitalizations, outpatient clinic visits, emergency department visits, urgent care visits, and mortality data, as well as additional birth information (eg, birth weight) when available. Other information sources, such as medical chart review, member surveys, and pharmacy, laboratory, and radiology data, are often used in VSD studies to validate outcomes and vaccination data. Since 2000, the VSD has undergone significant changes including an increase in the number of participating MCOs and enrolled population, changes in data-collection procedures, the creation of near real-time data files, and the development of near real-time postmarketing surveillance for newly licensed vaccines or changes in vaccine recommendations. Recognized as an important resource in vaccine safety, the VSD is working toward increasing transparency through data-sharing and external input. With its recent enhancements, the VSD provides scientific expertise, continues to develop innovative approaches for vaccine-safety research, and may serve as a model for other patient safety collaborative research projects.

The impact of pandemic influenza H1N1 on health-related quality of life: a prospective population-based study

Background

While the H1N1v influenza pandemic in 2009 was clinically mild, with a low case-fatality rate, the overall disease burden measured in quality-adjusted life years (QALY) lost has not been estimated. Such a measure would allow comparison with other diseases and assessment of the cost-effectiveness of pandemic control measures.

Methods and Findings

Cases of H1N1v confirmed by polymerase chain reaction (PCR) and PCR negative cases with similar influenza-like illness (ILI controls) in 7 regions of England were sent two questionnaires, one within a week of symptom onset and one two weeks later, requesting information on duration of illness, work loss and antiviral use together with EQ-5D questionnaires. Results were compared with those for seasonal influenza from a systematic literature review. A total QALY loss for the 2009 pandemic in England was calculated based on the estimated total clinical cases and reported deaths. A total of 655 questionnaires were sent and 296 (45%) returned. Symptoms and average illness duration were similar between confirmed cases and ILI controls (8.8 days and 8.7 days respectively). Days off work were greater for cases than ILI controls (7.3 and 4.9 days respectively, p = 0.003). The quality-adjusted life days lost was 2.92 for confirmed cases and 2.74 for ILI controls, with a reduction in QALY loss after prompt use of antivirals in confirmed cases. The overall QALY loss in the pandemic was estimated at 28,126 QALYs (22,267 discounted) of which 40% was due to deaths (24% with discounting).

Conclusion

Given the global public health significance of influenza, it is remarkable that no previous prospective study of the QALY loss of influenza using standardised and well validated methods has been performed. Although the QALY loss was minor for individual patients, the estimated total burden of influenza over the pandemic was substantial when compared to other infectious diseases.

Measuring health and well-being effects in family caregivers of children with craniofacial malformations

PURPOSE

This research explores the sensitivity of three generic instruments for preference-weighting health states of family caregivers of children with craniofacial malformations (CFM). We also examine the construct validity of the new CarerQol instrument measuring caregiver burden and general quality of life.

METHODS

Caregivers of children born with CFM were identified through the Arkansas Reproductive Health Monitoring System. A mailed survey included the HUI3, the SF-6D, the QWB-SA to measure health-related quality of life; the CES-D measuring depressive symptoms as well as the SRB scale, and the CarerQol. The HUI3, the SF-6D, and the QWB-SA were examined in relation to the CES-D the SRB, the CarerQol, and each other.

RESULTS

A total of 65 (63%) parents of children (≤17 years) responded. The mean SF-6D, HUI3, and QWB-SA scores were 0.81 (SD = 0.13), 0.84 (SD = 0.23), and 0.67 (SD = 0.14), respectively. The mean CES-D score was 13.3 (SD = 13.4) and 28.6% of the sample met a threshold for depressive symptoms (CES-D ≥ 16). The mean CarerQol-VAS and SRB scores were 7.5 (SD = 2.3) and 15.1 (SD = 23.5), respectively. The Spearman correlations (ρ) of the HUI3 and the SF-6D with the CES-D were similar (-0.81 and -0.76) while the ρ was lower (-0.57) for the QWB-SA. Preference-weighted scores of caregivers with CES-D scores ≥ 16 differed significantly for both the SF-6D and the HUI3, but not the QWB-SA. All three generic instruments showed moderate to strong relationships with the CarerQol.

CONCLUSIONS

The HUI3 and SF-6D were more sensitive predictors of depressive symptoms in this caregiver sample than was the QWB-SA. The CarerQol showed good construct validity and may be useful for measuring well-being effects associated with caregiving.

From the patient perspective: the economic value of seasonal and H1N1 influenza vaccination

Although studies have suggested that a patient's perceived cost-benefit of a medical intervention could affect his or her utilization of the intervention, the economic value of influenza vaccine from the patient's perspective remains unclear. Therefore, we developed a stochastic decision analytic computer model representing an adult's decision of whether to get vaccinated. Different scenarios explored the impact of the patient being insured versus uninsured, influenza attack rate, vaccine administration costs and vaccination time costs. Results indicated that the cost of avoiding influenza was fairly low (with one driver being required vaccination time). To encourage vaccination, decision makers may want to focus on ways to reduce this time, such as vaccinating at work, churches, or other normally frequented locations.

Valuing health across the lifespan: health state preferences for seasonal influenza illnesses in patients of different ages

OBJECTIVE

This study sought to measure whether public values for health states vary with the age of the affected individual.

METHODS

Health state preferences were measured via a 15-minute survey administered through the Internet in December 2007 using a probability sample of the adult population of the United States (N = 1012). Respondents were asked to value hypothetical descriptions of seasonal influenza illness (uncomplicated influenza illness, hospitalization) and possible vaccine-related adverse events (anaphylaxis, Guillain-Barré syndrome) using time trade-off or willingness-to-pay questions. Respondents were randomized to four different ages for an affected hypothetical individual: 1-year-old, 8-year-old, 35-year-old, 85-year-old. All other aspects of the health state description were held constant. Summary statistics for each health state and age were calculated. The Kruskal-Wallis test was used to measure differences in responses across ages of affected individuals in the hypothetical scenarios. Regression analyses were used to evaluate the effect of age on time trade-off or willingness-to-pay amounts controlling for respondent characteristics.

RESULTS

Median values for time trade-off and willingness-to-pay were highest for young children. This pattern was generally consistent across responses and type of valuation.

CONCLUSIONS

Approaches that assume health state values do not differ with the age of a patient may bias economic analyses that use these values. If patient age is likely to affect health state valuations, then age should be included as an attribute in the valuation exercise.

Determinants of influenza immunization uptake in Canadian youths

OBJECTIVE

To describe rate and determinants of influenza vaccination among Canadian youths.

METHODS

We conducted an analysis of cross-sectional data from the Canadian Community Health Survey (CCHS) cycle 3.1 collected by Statistics Canada in 2005. This is a population-based survey collecting information pertaining to the Canadian population health status, health care utilization and health determinants. The CCHS 3.1 included 12,170 respondents age 12-17 years old who answered questions pertaining to influenza vaccination. We used multivariate logistic regression to estimate the odds of having received the influenza vaccination in the last 12 months, adjusting for potential confounders.

RESULTS

Less than a quarter of Canadian youth reported receiving the influenza vaccination in the previous year. The most common reason for not getting the vaccination was "did not think it was necessary" (40.82%). Having chronic illness, and being an immigrant was significantly associated with a higher odds of receiving the influenza vaccination, while having an allergy and increasing frequency of alcohol drinking was associated with lower odds of receiving influenza vaccination. Smoking status acted as an effect modifier for many variables except for immigration status.

CONCLUSIONS

Influenza vaccination rate in Canadian youths is low. Judgement values on its necessity are a major factor in the decision to receive influenza vaccination. Strategies to involve youths in influenza vaccination programs and campaigns will be essential to achieve better national coverage.

Is the societal approach wide enough to include relatives? Incorporating relatives' costs and effects in a cost-effectiveness analysis

It is important for economic evaluations in healthcare to cover all relevant information. However, many existing evaluations fall short of this goal, as they fail to include all the costs and effects for the relatives of a disabled or sick individual. The objective of this study was to analyse how relatives' costs and effects could be measured, valued and incorporated into a cost-effectiveness analysis. In this article, we discuss the theories underlying cost-effectiveness analyses in the healthcare arena; the general conclusion is that it is hard to find theoretical arguments for excluding relatives' costs and effects if a societal perspective is used. We argue that the cost of informal care should be calculated according to the opportunity cost method. To capture relatives' effects, we construct a new term, the R-QALY weight, which is defined as the effect on relatives' QALY weight of being related to a disabled or sick individual. We examine methods for measuring, valuing and incorporating the R-QALY weights. One suggested method is to estimate R-QALYs and incorporate them together with the patient's QALY in the analysis. However, there is no well established method as yet that can create R-QALY weights. One difficulty with measuring R-QALY weights using existing instruments is that these instruments are rarely focused on relative-related aspects. Even if generic quality-of-life instruments do cover some aspects relevant to relatives and caregivers, they may miss important aspects and potential altruistic preferences. A further development and validation of the existing caregiving instruments used for eliciting utility weights would therefore be beneficial for this area, as would further studies on the use of time trade-off or Standard Gamble methods for valuing R-QALY weights. Another potential method is to use the contingent valuation method to find a monetary value for all the relatives' costs and effects. Because cost-effectiveness analyses are used for decision making, and this is often achieved by comparing different cost-effectiveness ratios, we argue that it is important to find ways of incorporating all relatives' costs and effects into the analysis. This may not be necessary for every analysis of every intervention, but for treatments where relatives' costs and effects are substantial there may be some associated influence on the cost-effectiveness ratio.

Oseltamivir for influenza postexposure prophylaxis: economic evaluation for children aged 1-12 years in the U.S

BACKGROUND

Postexposure prophylaxis (PEP) with oseltamivir (Tamiflu) has been shown to be effective and is approved in children exposed to a case of influenza in a household setting. Given limited healthcare budgets, it is important to understand the costs and cost effectiveness of PEP in children.

PURPOSE

This study aims to estimate the cost effectiveness of oseltamivir PEP for children aged 1-12 years in the U.S.

METHODS

A decision-tree model with a 1-year time horizon was used to assess the cost effectiveness of oseltamivir PEP for 10 days at approved doses compared with no prophylaxis for children aged 1-12 years who were exposed to a household index case of influenza from the U.S. societal and payer perspectives. Model inputs included U.S. influenza epidemiology data, efficacy data from oseltamivir PEP clinical trials, direct medical resource use and costs for PEP and influenza treatment derived from large U.S. databases, and indirect costs based on caregiver lost productivity. Base-case estimates were tested in extensive sensitivity analyses.

RESULTS

For the societal perspective, the model estimated 12,184 fewer cases of influenza per 100,000 children exposed and an incremental cost-effectiveness ratio of $41,452 per quality-adjusted life-year (QALY) gained. Results were most sensitive to the influenza attack rate, PEP protective efficacy, and prescribing patterns for initiating PEP. Probabilistic sensitivity analyses showed that oseltamivir PEP was likely to be cost effective for all willingness-to-pay threshold values above $34,300 per QALY gained. Results were similar for the payer perspective.

CONCLUSIONS

Although there is no official cost-effectiveness threshold in the U.S., results from the current study show that when compared with no prophylaxis, oseltamivir PEP for children has cost-effectiveness ratios similar to those of vaccines for preventing influenza.

Valuation of the economic benefits of human papillomavirus vaccine in Taiwan

OBJECTIVES

The study aims to apply the contingent valuation method to elicit the willingness-to-pay (WTP), and measure the value of a statistic life (VSL), for human papillomavirus (HPV) vaccine in Taiwan.

METHODS

A total of 512 questionnaires were completed on women aged 20 to 55 years with at least one daughter, during March through May 2007. The respondents' WTP for the vaccines was elicited by double-bounded binary-choice questions under two scenarios: one was to protect themselves from cervical cancer (CC) and the other was for their daughter(s). The WTP was modeled as a function of the respondents' knowledge score, attitudes toward CC and HPV vaccine, the vaccination outcome scenarios, and individual characteristics. A log-normal survival model was constructed and the maximum-likelihood method was used for estimation.

RESULTS

The median regression-adjusted WTP was estimated at US$1098 to US$1233 (US$913-1004) for vaccinating the daughter (mother); and the VSL was estimated at approximately US$0.65 to US$4.09 (US$0.56-3.16) million for vaccinating the daughter (mother).

CONCLUSIONS

The study results provided important evidences on the monetary value women placed on a HPV vaccine, and the differential benefits between vaccinating the women and their daughters.

An economic analysis of anemia prevention during infancy

OBJECTIVE

To compare the cost-benefit profile of reticulocyte hemoglobin content (CHr) with hemoglobin (Hb) alone and Hb as a component of the complete blood count (CBC) for detection and treatment of iron deficiency in 9- to 12-month-old infants.

STUDY DESIGN

Cohort simulations were used to compare CHr with Hb from a societal perspective. Assumptions included a 9% prevalence of iron deficiency and testing characteristics/costs of CHr, Hb, and CBC (CHr <27.5 pg: sensitivity 83%, specificity 72%, $11; Hb <11 g/dL: sensitivity 26%, specificity 95%, $5; CBC Hb<11g/dL, $15), as well as cost of iron therapy ($61 for established anemia). Sensitivity analyses were performed.

RESULTS

Under current market conditions, the incremental cost to diagnose and treat iron deficiency, compared with diagnosing and treating anemia by Hb, was only $22 per patient screened ($440 per case of anemia prevented; number needed to treat = 20). With a 10-year time horizon incorporating risks and costs of neurocognitive delays associated with untreated iron deficiency, the cost of the CHr strategy was $280 per case of anemia prevented.

CONCLUSIONS

CHr is an affordable strategy to prevent anemia in infants with possible iron deficiency.

Prevention of influenza: recommendations for influenza immunization of children, 2007-2008

The American Academy of Pediatrics recommends annual influenza immunization for all children with high-risk conditions who are 6 months of age and older, for all healthy children ages 6 through 59 months, for all household contacts and out-of-home caregivers of children with high-risk conditions and of healthy children younger than 5 years, and for all health care professionals. To more fully protect against the morbidity and mortality of influenza, increased efforts are needed to identify and immunize all children at high risk and all healthy children ages 6 through 59 months and to inform their parents when annual immunizations are due. Previously unimmunized children who are at least 6 months of age but younger than 9 years should receive 2 doses of influenza vaccine, given 1 month apart, beginning as soon as possible on the basis of local availability during the influenza season. If children in this cohort received only 1 dose for the first time in the previous season, it is recommended that 2 doses be administered in the current season. This recommendation applies only to the influenza season that follows the first year that a child younger than 9 years receives influenza vaccine. A child who then also fails to receive 2 doses the next year should be given only 1 dose per year from that point on. Influenza vaccine should also continue to be offered throughout the influenza season, even after influenza activity has been documented in a community. On the basis of global surveillance of circulating virus strains, the influenza vaccine may change from year to year; indeed, 1 of the 3 strains in the 2007-2008 vaccine is different from the previous year's vaccine. All health care professionals, influenza campaign organizers, and public health agencies should develop plans for expanding outreach and infrastructure to immunize all children for whom influenza vaccine is recommended. Appropriate prioritization of administering influenza vaccine will also be necessary when vaccine supplies are delayed or limited. Because the influenza season often extends into March, immunization against influenza is recommended to continue through late winter and early spring. Lastly, it is recommended that for the 2007-2008 season, and likely beyond, health care professionals do not prescribe amantadine or rimantadine for influenza treatment or chemoprophylaxis, because widespread resistance to these antiviral medications now exists among influenza A viral strains. However, oseltamivir and zanamivir can be prescribed for treatment or chemoprophylaxis, because influenza A and B strains remain susceptible.

Non-traditional settings for influenza vaccination of adults: costs and cost effectiveness

OBJECTIVE

Influenza vaccination rates remain far below national goals in the US. Expanding influenza vaccination in non-traditional settings such as worksites and pharmacies may be a way to enhance vaccination coverage for adults, but scant data exist on the cost effectiveness of this strategy. The aims of this study were to (i) describe the costs of vaccination in non-traditional settings such as pharmacies and mass vaccination clinics; and (ii) evaluate the projected health benefits, costs and cost effectiveness of delivering influenza vaccination to adults of varying ages and risk groups in non-traditional settings compared with scheduled doctor's office visits. All analyses are from the US societal perspective.

METHODS

We evaluated the costs of influenza vaccination in non-traditional settings via detailed telephone interviews with representatives of organizations that conduct mass vaccination clinics and pharmacies that use pharmacists to deliver vaccinations. Next, we constructed a decision tree to compare the projected health benefits and costs of influenza vaccination delivered via non-traditional settings or during scheduled doctor's office visits with no vaccination. The target population was stratified by age (18-49, 50-64 and >or=65 years) and risk status (high or low risk for influenza-related complications). Probabilities and costs (direct and opportunity) for uncomplicated influenza illness, outpatient visits, hospitalizations, deaths, vaccination and vaccine adverse events were derived from primary data and from published and unpublished sources.

RESULTS

The mean cost (year 2004 values) of vaccination was lower in mass vaccination (dollars US 17.04) and pharmacy (dollars US 11.57) settings than in scheduled doctor's office visits (dollars US 28.67). Vaccination in non-traditional settings was projected to be cost saving for healthy adults aged >or=50 years, and for high-risk adults of all ages. For healthy adults aged 18-49 years, preventing an episode of influenza would cost dollars US 90 if vaccination were delivered via the pharmacy setting, dollars US 210 via the mass vaccination setting and dollars US 870 via a scheduled doctor's office visit. Results were sensitive to assumptions on the incidence of influenza illness, the costs of vaccination (including recipient time costs) and vaccine effectiveness.

CONCLUSION

Using non-traditional settings to deliver routine influenza vaccination to adults is likely to be cost saving for healthy adults aged 50-64 years and relatively cost effective for healthy adults aged 18-49 years when preferences for averted morbidity are included.

Exploring preference anomalies in double bounded contingent valuation

Double bounded dichotomous choice (DBDC) contingent valuation offers increased efficiency of willingness to pay (WTP) estimates compared with the single bounded format. However, evidence suggests DBDC generates anomalous respondent behaviour. This paper provides the first investigation and explanation of these anomalies in health. Results suggest the incentives for truthful preference revelation are altered in the presence of a follow up question. This result is found using both regression techniques and analysis of raw responses. Although findings suggest 'very certain' respondents exhibit less anomalous behaviour inconsistencies remain across bounds. The results of this study question the use of iterative valuation formats.

Health benefits, risks, and cost-effectiveness of influenza vaccination of children

Vaccinating children aged 6–23 months, plus all other children at high-risk, will likely be more effective than vaccinating all children against influenza.

We estimated cost-effectiveness of annually vaccinating children not at high risk with inactivated influenza vaccine (IIV) to range from US $12,000 per quality-adjusted life year (QALY) saved for children ages 6–23 months to $119,000 per QALY saved for children ages 12–17 years. For children at high risk (preexisting medical conditions) ages 6–35 months, vaccination with IIV was cost saving. For children at high risk ages 3–17 years, vaccination cost $1,000–$10,000 per QALY. Among children not at high risk ages 5–17 years, live, attenuated influenza vaccine had a similar cost-effectiveness as IIV. Risk status was more important than age in determining the economic effects of annual vaccination, and vaccination was less cost-effective as the child's age increased. Thus, routine vaccination of all children is likely less cost-effective than vaccination of all children ages 6–23 months plus all other children at high risk.

Measuring health preferences for use in cost-utility and cost-benefit analyses of interventions in children: theoretical and methodological considerations

Valuing the health of children for cost-utility or cost-benefit analysis poses a number of additional challenges when compared with valuing adult health. Some of these challenges relate to the inability of young children to value changes in health directly and the potential biases associated with using proxy respondents. Other challenges arise from children not being able to perform as independent economic actors, but dependent on others for care and decision making. In addition, illness in children may affect parent/caregiver quality of life, further complicating the measurement of value associated with a change in a child's health status. We review the most common approaches (QALYs and willingness-to-pay values) for valuing health in economic evaluations and consider the methodological and practical issues associated with measuring child health using each framework. Recommendations for advancing the field of valuing child health for economic evaluations will vary by age; a 'one size fits all' approach does not readily fit. Although limitations exist for all of the methods considered for valuing child health, the currently recommended approach for infants and preschoolers is direct valuation by a proxy respondent. For school-age children and adolescents, existing multi-attribute instruments can be applied in some situations but direct valuation may be required for others. Future research should focus on minimising bias from proxy respondents, consideration of a family- or household-based approach to valuing health effects, and development of generic instruments with domains that are appropriate to children and that vary with age.

Conjoint analysis of French and German parents' willingness to pay for meningococcal vaccine

OBJECTIVE

To estimate the willingness of parents in France and Germany to pay for meningococcal conjugate vaccines for their teenage children.

METHODS

A conjoint analysis survey was administered to parents who had received counselling on the nature and risks of meningococcal disease in young people. In each country, half were randomly assigned to view a video with graphical depictions of the effects of meningococcaemia. Subjects were then shown a series of 18 sets of three vaccine descriptions. Each description listed the price of a hypothetical vaccine (range 15-304 euro; 2001 values), the duration of protection, and the number of serogroups of the bacteria covered. The survey asked which vaccine they preferred and whether they would buy it. Conditional logit and generalised linear-random effects logit models assessed the effect of product attributes, personal background and video viewership on the probability of indicating a purchase.

RESULTS

92.6% of subjects would purchase at least one of the vaccines they encountered. Price elasticity ranged from -1.20 (France) to -2.48 (Germany). Exposure to graphical depictions of disease consequences negligibly increased the overall willingness to purchase vaccine in French participants, but lowered the overall willingness in German participants.

CONCLUSION

In Germany and France, where there is still limited out-of-pocket health spending, the majority of sampled respondents stated that they would purchase meningococcal vaccines with their own money.