Respiratory syncytial virus prophylaxis: cost-effective analysis in Argentina

Cost of childhood RSV management and cost-effectiveness of RSV interventions: a systematic review from a low- and middle-income country perspective

BACKGROUND

Approximately 97% of global deaths due to RSV occur in low- and middle-income countries (LMICs). Until recently, the only licensed preventive intervention has been a shortacting monoclonal antibody (mAb), palivizumab (PVZ) that is expensive and intensive to administer, making it poorly suited for low-resource settings. Currently, new longer acting RSV mAbs and maternal vaccines are emerging from late-stage clinical development with promising clinical effectiveness. However, evidence of economic value and affordability must also be considered if these interventions are to be globally accessible. This systematic review's objective was to summarise existing evidence on the cost-of-illness (COI) and cost-effectiveness of RSV prevention interventions in LMICs.

METHODS

We conducted a systematic literature review using the Embase, MEDLINE, and Global Index Medicus databases for publications between Jan 2000 and Jan 2022. Two categories of studies in LMICs were targeted: cost-of-illness (COI) of RSV episodes and cost-effectiveness analyses (CEA) of RSV preventive interventions including maternal vaccines and long-acting mAbs. Of the 491 articles reviewed, 19 met the inclusion criteria.

RESULTS

COI estimates varied widely: for severe RSV, the cost per episode ranged from $92 to $4114. CEA results also varied-e.g. evaluations of long-acting mAbs found ICERs from $462/DALY averted to $2971/DALY averted. Study assumptions of input parameters varied substantially and their results often had wide confidence intervals.

CONCLUSIONS

RSV represents a substantial disease burden; however, evidence of economic burden is limited. Knowledge gaps remain regarding the economic value of new technologies specifically in LMICs. Further research is needed to understand the economic burden of childhood RSV in LMICs and reduce uncertainty about the relative value of anticipated RSV prevention interventions. Most CEA studies evaluated palivizumab with fewer analyses of interventions in development that may be more accessible for LMICs.

Challenges in the prevention or treatment of RSV with emerging new agents in children from low- and middle-income countries

INTRODUCTION

Respiratory syncytial virus (RSV) causes approximately 120,000 deaths annually in children <5 years, with 99% of fatalities occurring in low- and middle-income countries (LMICs).

AREAS COVERED

There are numerous RSV interventions in development, including long-acting monoclonal antibodies, vaccines (maternal and child) and treatments which are expected to become available soon. We reviewed the key challenges and issues that need to be addressed to maximize the impact of these interventions in LMICs. The epidemiology of RSV in LMICs was reviewed (PubMed search to 30 June 2020 inclusive) and the need for more and better-quality data, encompassing hospital admissions, community contacts, and longer-term respiratory morbidity, emphasized. The requirement for an agreed clinical definition of RSV lower respiratory tract infection was proposed. The pros and cons of the new RSV interventions are reviewed from the perspective of LMICs.

EXPERT OPINION

We believe that a vaccine (or combination of vaccines, if practicable) is the only viable solution to the burden of RSV in LMICs. A coordinated program, analogous to that with polio, involving governments, non-governmental organizations, the World Health Organization, the manufacturers and the healthcare community is required to realize the full potential of vaccine(s) and end the devastation of RSV in LMICs.

Should we use Palivizumab immunoprophylaxis for infants against respiratory syncytial virus? - a cost-utility analysis

BACKGROUND

Passive immunization against RSV (Respiratory Syncytial Virus) is given in most western countries (including Israel) to infants of high risk groups such as premature babies, and infants with Congenital Heart Disease or Congenital Lung Disease. However, immunoprophylaxis costs are extremely high ($2800-$4200 per infant). Using cost-utility analysis criteria, we evaluate whether it is justified to expand, continue or restrict nationwide immunoprophylaxis using palivizumab of high risk infants against RSV.

METHODS

Epidemiological, demographic, health service utilisation and economic data were integrated from primary (National Hospitalization Data, etc.) and secondary data sources (ie: from published articles) into a spread-sheet to calculate the cost per averted disability-adjusted life year (DALY) of vaccinating various infant risk groups. Costs of intervention included antibody plus administration costs. Treatment savings and DALYs averted were estimated from applying vaccine efficacy data to relative risks of being hospitalised and treated for RSV, including possible long-term sequelae like asthma and wheezing.

RESULTS

For all the groups RSV immunoprophylaxis is clearly not cost effective as its cost per averted DALY exceeds the $105,986 guideline representing thrice the per capita Gross Domestic Product. Vaccine price would have to fall by 48.1% in order to justify vaccinating Congenital Heart Disease or Congenital Lung Disease risk groups respectively on pure cost-effectiveness grounds. For premature babies of < 29 weeks, 29-32 and 33-36 weeks gestation, decreases of 36.8%, 54.5% and 83.3% respectively in vaccine price are required.

CONCLUSIONS

Based solely on cost-utility analysis, at current price levels it is difficult to justify the current indications for passive vaccination with Palivizumab against RSV. However, if the manufacturers would reduce the price by 54.5% then it would be cost-effective to vaccinate the Congenital Heart Disease or Congenital Lung Disease risk groups as well as premature babies born before the 33rd week of gestation.

Timing of respiratory syncytial virus and influenza epidemic activity in five regions of Argentina, 2007-2016

Background

Within‐country differences in the timing of RSV and influenza epidemics have not been assessed in Argentina, the eighth largest country in the world by area.

Objective

We aimed to compare seasonality for RSV and influenza both nationally and in each of the five regions to inform Argentina’s prevention and treatment guidelines.

Method

The Argentine National Laboratories and Health Institutes Administration collected respiratory specimens from clinical practices, outbreak investigations, and respiratory virus surveillance in 2007‐2016; these were tested using immunofluorescence or RT‐PCR techniques. We calculated weekly percent positive (PP) and defined season onset as >2 consecutive weeks when PP exceeded the annual mean for the respective year and region. Median season measures (onset, offset and peak) and the established mean method were calculated for each virus.

Results

An annual median 59 396 specimens were tested for RSV and 60 931 for influenza; 21–29% tested positive for RSV and 2–7% for influenza. National RSV activity began in April; region‐specific start weeks varied by 7 weeks. Duration of RSV activity did not vary widely by region (16–18 weeks in duration). National influenza activity started in June; region‐specific start weeks varied by 3 weeks. Duration of influenza epidemic activity varied more by region than that of RSV (7–13 weeks in duration).

Conclusion

In Argentina, RSV and influenza activity overlapped during the winter months. RSV season tended to begin prior to the influenza season, and showed more variation in start week by region. Influenza seasons tended to vary more in duration than RSV seasons.

Risk of respiratory syncytial virus infection in preterm infants: reviewing the need for prevention

Premature infants are at substantial risk for a spectrum of morbidities that are gestational age dependent. Respiratory syncytial virus (RSV) infection is most common in the first two years of life with the highest burden in children aged <6 months. Preterm infants ≤35 weeks' gestation are handicapped by incomplete immunological and pulmonary maturation and immature premorbid lung function with the added risk of bronchopulmonary dysplasia. Superimposed RSV infection incites marked neutrophilic airway inflammation and innate immunological responses that further compromise normal airway modeling. This review addresses the epidemiology and burden of RSV disease, focusing on the preterm population. Risk factors that determine RSV-disease severity and hospitalization and the impact on healthcare resource utilization and potential long-term respiratory sequelae are discussed. The importance of disease prevention and the evidence-based rationale for prophylaxis with palivizumab is explored, while awaiting the development of a universal vaccine.

The Argentina Premature Asthma and Respiratory Team (APART): objectives, design, and recruitment results of a prospective cohort study of viruses and wheezing in very low birth weight infants

Background

Asthma and wheezing account for a substantial disease burden around the world. Very low birth weight (VLBW, <1500 grams) infants are at an increased risk for the development of severe acute respiratory illness (ARI) and recurrent wheeze/asthma. The role of respiratory viruses in asthma predisposition in premature infants is not well understood. Preliminary evidence suggests that infection with human rhinovirus (RV) early in life may contribute to greater burden of asthma later in life.

Methods

A prospective cohort study of premature VLBW infants from Buenos Aires, Argentina, was enrolled year-round during a three-year period in the neonatal intensive care unit and followed during every ARI and with monthly well visits during the first year of life. Longitudinal follow-up up until age five years is ongoing.

Results

This report describes the objectives, design, and recruitment results of this prospective cohort. Two hundred and five patients were enrolled from August 2011 through January 2014, and follow-up is ongoing. A total of 319 ARI episodes were observed from August 2011 to July 2014, and 910 well visits occurred during this time period.

Conclusions

The Argentina Premature Asthma and Respiratory Team (APART) is a unique cohort consisting of over 200 patients and over 1200 specimens who have been and will continue to be followed intensively from NICU discharge to capture baseline risk factors and every ARI, with interceding well visits during the first year of life, as well as longitudinal follow-up to age 5 years for asthma and atopy outcomes.

Systematic review and meta-analysis of respiratory syncytial virus infection epidemiology in Latin America

Respiratory syncytial virus (RSV) is a frequent cause of acute respiratory infection and the most common cause of bronchiolitis in infants. The aim of this systematic review and meta-analysis was to obtain a comprehensive epidemiological picture of the data available on disease burden, surveillance, and use of resources in Latin America. Pooled estimates are useful for cross-country comparisons. Data from published studies reporting patients with probable or confirmed RSV infection in medical databases and gray literature were included from 74 studies selected from the 291 initially identified. When considering all countries, the largest pooled percentage RSV in low respiratory tract infection patients was found in the group between 0 and 11 months old, 41.5% (95% CI 32.0–51.4). In all countries, percentages were increasingly lower as older children were included in the analyses. The pooled percentage of RSV in LRTIs in the elderly people was 12.6 (95% CI 4.2–24.6). The percentage of RSV infection in hospitalized newborns was 40.9% (95% CI 28.28–54.34). The pooled case fatality ratio for RSV infection was 1.74% (95% CI 1.2–2.4) in the first 2 years of life. The average length of stay excluding intensive care unit admissions among children with risk factors for severe disease was 12.8 (95% CI 8.9–16.7) days, whereas it averaged 7.3 (95% CI 6.1/8.5) days in otherwise healthy children.We could conclude that infants in their first year of age were the most vulnerable population. To our knowledge, this is the first systematic review on RSV disease burden and use of health resources in Latin America.

Pediatricians' attitudes and costs of bronchiolitis in the emergency department: a prospective multicentre study

BACKGROUND

How pediatricians manage bronchiolitis and the derived total costs (direct and indirect) in the emergency department (ED) have not been fully characterized. The aim of the present study is to calculate those costs in a European country.

METHODS

A prospective and observational study, including 10 EDs of tertiary hospitals throughout Spain and during the bronchiolitis season 2010-2011, was performed. Every ED recruited children on random days of the week (3 days per week; always including one non-working day per every week). Recruitment aimed at a total sample size of 600 children. Direct (diagnostic procedures, time spent in the ED and medication) and indirect costs (work hours lost by parents, babysitting, travels, and meals) were collected. Comparisons between bronchiolitis caused by respiratory syncytial virus (RSV) and non-RSV bronchiolitis, as well as costs across severity categories were performed with the Kruskal-Wallis test. A multiple regression model was built to assess the influence of several of the studied factors on the total costs, including a RSV positive test and episode severity as independent variables; and gender, age, attending nursery school, preterm birth, low birth weight, smoker mother during pregnancy, and current smoker father as covariates.

RESULTS

From the 664 recruited children, direct mean costs were €213.2 ± 91.8 and indirect ones were €35.9 ± 55.3; the total costs being €249.2 ± 122.9. Costs were significantly higher in children positive to RSV and rose with increased severity. Those associations were maintained in the multiple regression analysis.

CONCLUSIONS

Although relatively low at the individual level (€249.2, mean total cost) the costs for just the ED expenses of bronchiolitis in Spain would add up to about €20 million per year.

Monoclonal antibody for reducing the risk of respiratory syncytial virus infection in children

BACKGROUND

Respiratory syncytial virus (RSV) is one of the most important viral pathogens causing acute respiratory infections in children. It results in about 3.4 million hospitalisations annually in children under five. Palivizumab is an anti-RSV monoclonal antibody, administered intramuscularly at a dose of 15 mg/kg once every 30 days. The efficacy and safety of palivizumab has been evaluated in multicentre, randomised controlled trials (RCTs) and a large number of economic evaluations (EEs) have tested its cost-effectiveness.

OBJECTIVES

To assess the effectiveness and safety of palivizumab prophylaxis compared with placebo, or another type of prophylaxis, in reducing the risk of complications (hospitalisation due to RSV infection) in high-risk infants and children. To assess the cost-effectiveness (or cost-utility) of palivizumab prophylaxis compared with no prophylaxis in infants and children in different risk groups.

SEARCH METHODS

We searched CENTRAL 2012, Issue 7, MEDLINE (1996 to July week 4, 2012), EMBASE (1996 to August 2012), CINAHL (1996 to August 2012) and LILACS (1996 to August 2012) for studies of effectiveness and safety. We searched the NHS Economic Evaluations Database (NHS EED 2012, Issue 4), Health Economics Evaluations Database (HEED, 9 August 2012) and Paediatric Economic Database Evaluations (PEDE, 1980 to 2009), MEDLINE (1996 to July week 4, 2012) and EMBASE (1996 to August 2012) for economic evaluations.

SELECTION CRITERIA

We included RCTs comparing palivizumab prophylaxis with a placebo, no prophylaxis or another type of prophylaxis in preventing serious lower respiratory tract disease caused by RSV in paediatric patients at high risk. We included cost-effectiveness analyses and cost-utility analyses comparing palivizumab prophylaxis with no prophylaxis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias for the included studies and extracted data for both the RCTs and EEs. We calculated risk ratios (RRs) and their associated 95% confidence intervals (CIs) for dichotomous outcomes and for adverse events (AEs). We provided a narrative summary of results for continuous outcomes, due to missing data on standard deviations. We performed fixed-effect meta-analyses for the estimation of pooled effects whenever there was no indication of heterogeneity between included RCTs. We summarised the results reported in included EEs, such as incremental costs, incremental effectiveness, and incremental cost-effectiveness and/or cost-utility ratios (ICERs), and we calculated ICER present values in 2011 Euros for all studies.

MAIN RESULTS

Of the seven available RCTs, three compared palivizumab with a placebo in a total of 2831 patients, and four compared palivizumab with motavizumab in a total of 8265 patients. All RCTs were sponsored by the drug manufacturing company. The overall quality of RCTs was good, but for most of the outcomes assessed only data from two studies contributed to the analysis. Palivizumab prophylaxis was associated with a statistically significant reduction in RSV hospitalisations (RR 0.49, 95% CI 0.37 to 0.64) when compared to placebo. When compared to motavizumab, palivizumab recipients showed a non-significant increase in the risk of RSV hospitalisations (RR 1.36, 95% CI 0.97 to 1.90). In both cases, the proportion of children with any AE or any AE related to the study drug was similar between the two groups.In terms of economic evidence, we included 34 studies that reported cost-effectiveness and/or cost-utility data for palivizumab prophylaxis compared with no prophylaxis, in high-risk children with different underlying medical conditions. The overall quality of EEs was good, but the variations in modelling approaches were considerable across the studies, leading to big differences in cost-effectiveness results. The cost-effectiveness of palivizumab prophylaxis depends on the consumption of resources taken into account by the study authors; and on the cost-effectiveness threshold set by the healthcare sector in each country.

AUTHORS' CONCLUSIONS

There is evidence that palivizumab prophylaxis is effective in reducing the frequency of hospitalisations due to RSV infection, i.e. in reducing the incidence of serious lower respiratory tract RSV disease in children with chronic lung disease, congenital heart disease or those born preterm.Results from economic evaluations of palivizumab prophylaxis are inconsistent, implying that economic findings must be interpreted with caution. ICER values varied considerably across studies, from highly cost-effective to not cost-effective. The availability of low-cost palivizumab would reduce its inequitable distribution, so that RSV prophylaxis would be available to the poorest countries where children are at greatest risk.

Use of number needed to treat in cost-effectiveness analyses

OBJECTIVE

To review the use of number needed to treat (NNT) and/or number needed to harm (NNH) values to determine their relevance in helping clinicians evaluate cost-effectiveness analyses (CEAs).

DATA SOURCES

PubMed and EconLit were searched from 1966 to September 2012.

STUDY SELECTION AND DATA EXTRACTION

Reviews, editorials, non-English-language articles, and articles that did not report NNT/NNH or cost-effectiveness ratios were excluded. CEA studies reporting cost per life-year gained, per quality-adjusted life-year (QALY), or other cost per effectiveness measure were included. Full texts of all included articles were reviewed for study information, including type of journal, impact factor of the journal, focus of study, data source, publication year, how NNT/NNH values were reported, and outcome measures.

DATA SYNTHESIS

A total of 188 studies were initially identified, with 69 meeting our inclusion criteria. Most were published in clinician-practice-focused journals (78.3%) while 5.8% were in policy-focused journals, and 15.9% in health-economics-focused journals. The majority (72.4%) of the articles were published in high-impact journals (impact factor >3.0). Many articles focused on either disease treatment (40.5%) or disease prevention (40.5%). Forty-eight percent reported NNT as a part of the CEA ratio per event. Most (53.6%) articles used data from literature reviews, while 24.6% used data from randomized clinical trials, and 20.3% used data from observational studies. In addition, 10% of the studies implemented modeling to perform CEA.

CONCLUSIONS

CEA studies sometimes include NNT ratios. Although it has several limitations, clinicians often use NNT for decision-making, so including NNT information alongside CEA findings may help clinicians better understand and apply CEA results. Further research is needed to assess how NNT/NNH might meaningfully be incorporated into CEA publications.

Palivizumab in preventing respiratory syncytial virus-related hospitalization in high-risk infants

Respiratory syncytial virus (RSV) causes seasonal epidemics (winter or wet-season) of serious lower respiratory tract infections in young infants with subsequent increased frequency of recurrent wheezing during early childhood. Palivizumab is a humanized monoclonal antibody that provides immunoprophylaxis against RSV when administered monthly over the RSV season. It significantly reduced hospitalizations in high-risk infants including preterm infants with and without bronchopulmonary dysplasia and infants with hemodynamically significant congenital heart disease. Since its license in 1998, approximately 36 methodologically different economic studies have been performed to prove cost-effectiveness of the product. The majority of cost-effectiveness analyses revealed costs of palivizumab exceeding anticipated savings from reduced RSV hospitalizations. A minority of studies performed cost-effectiveness analyses using incremental cost-effectiveness ratios as costs per quality-adjusted life-year gained. The wide variability in the results of economic studies with estimates ranging from cost savings to incremental costs of a high order of magnitude with its use is discussed, in the light of the continuing burden of RSV disease, the limited treatment modalities, and the continuing research for a vaccine.

Cost-effectiveness of palivizumab in infancy

Respiratory syncytial virus is the most common cause of bronchiolitis, a lower respiratory tract infection occurring in infancy. It is responsible for several rehospitalizations, substantial morbidity and occasional deaths in the UK every year. Palivizumab is a recombinant monoclonal antibody that has been shown to reduce hospitalizations in infected infants. It is licensed for high-risk infants, primarily those born pre-term or with chronic pulmonary or cardiac conditions. Palivizumab is expensive, but several economic analyses have determined highly discrepant costs. This article reviews the limitations of the available efficacy and economic data, and highlights problems in interpretation and extrapolation. We also present the results of a cost-effectiveness analysis relevant to populations of high-risk infants in the UK.

Neonatology in the emerging countries: the strategies and health-economics challenges related to prevention of neonatal and infant infections

The prevalence of neonatal and infant infections is higher in emerging countries when compared to the developed world. Major factors associated to this increased frequency include the scarcity of trained health personnel, overcrowding of the neonatal units, late onset and slow advance of feeding, use of formula instead of breastfeeding, failure to comply with handwashing recommendations, and excessive use of antibiotics, resulting in the emergence of resistant strains. Infants discharged home frequently share rooms with a large number of siblings and other cohabitants, increasing the risk of infection by respiratory viruses. Several strategies are described that could decrease these serious problems which impact increasing significantly neonatal and infant mortality rates in developing countries.

Human rhinoviruses in severe respiratory disease in very low birth weight infants

OBJECTIVES

To assess incidence, burden of illness, and risk factors for human rhinoviruses (HRVs) in a cohort of very low birth weight (VLBW) infants.

METHODS

A 2-year prospective cohort study was conducted among VLBW premature infants in Buenos Aires, Argentina. Infants were enrolled in the NICU from June 1, 2003, to May 31, 2005, and managed monthly and with every acute respiratory illness (ARI) during the first year of life. Nasal wash samples were obtained during every respiratory episode and tested for HRV, respiratory syncytial virus (RSV), human parainfluenza viruses, influenza viruses, and human metapneumovirus using reverse transcriptase-polymerase chain reaction.

RESULTS

Of 119 patients, 66 (55%) had HRV-associated ARIs. The incidence of HRV-associated ARI was 123 events per 100 child-years of follow-up. Of those infants experiencing an episode of bronchiolitis, 40% had HRV versus 7% with RSV. The incidence of HRV-associated bronchiolitis was 75 per 100 infant-years of follow-up. HRV was associated with 12 of 36 hospitalizations (33%), and RSV was associated with 9 of 36 hospitalizations (25%). The incidence of HRV-associated hospitalization was 12 per 100 infant-years of follow-up. The risk of HRV-associated hospitalization was higher for infants with bronchopulmonary dysplasia and those who were not breastfed.

CONCLUSIONS

HRV is an important and frequent pathogen associated with severe respiratory infections in VLBW infants. Bronchopulmonary dysplasia and the absence of breastfeeding are risk factors for hospitalization. The results of our study reveal that HRV is the predominant pathogen of respiratory infections in premature infants.

Cost-effectiveness analysis of palivizumab among pre-term infant populations covered by Medicaid in the United States

OBJECTIVE

Medicaid infants are at high risk of severe respiratory syncytial virus (RSV) disease. The study objective was to estimate the cost-effectiveness of palivizumab in a Medicaid population.

METHODS

A societal cost-utility analysis was conducted of prophylaxis with palivizumab vs no prophylaxis among four groups of premature infants: (1) <32 weeks gestational age (wGA) and ≤ 6 months chronologic age (CA); (2) 32-34 wGA, ≤ 3 months CA with 2009 American Academy of Pediatrics (AAP) risk factors (RF); (3) 32-35 wGA, ≤ 6 months CA with 2006 AAP RF; and (4) 32-35 wGA, ≤ 6 months CA with ≤ 1 RF. Full dosing of palivizumab was assumed throughout the RSV season (consistent with the FDA-approved label). All costs were in 2010 US dollars. The societal public payer spend for palivizumab was estimated using Medicaid reimbursement methodologies for the top 10 palivizumab-using states in 2010 minus mandatory manufacturer rebates. This study reports the incremental cost-effectiveness ratios (ICERs) in cost per quality-adjusted life-year (QALY) gained. Sensitivity and probabilistic analyses were also conducted.

RESULTS

Palivizumab saved costs and improved QALYs among infants <32 wGA. Palivizumab was cost-effective in infants 32-34 wGA with 2009 AAP RF ($16,037 per QALY) and in infants 32-35 wGA with 2006 AAP RF ($38,244 per QALY). The ICER for infants 32-35 wGA with ≤ 1 RF was $281,892 per QALY. Influential variables in the sensitivity analysis included the background rate of RSV hospitalization, the cost of palivizumab, and the efficacy of palivizumab.

KEY LIMITATIONS

These results are not generalizable to commercially insured infants or infants outside of the US.

CONCLUSIONS

This is the first cost-utility analysis of palivizumab in a Medicaid population. Palivizumab, when dosed consistent with the FDA-approved labeling, was either cost-saving or cost-effective among current guideline-eligible infants in the Medicaid population. Palivizumab did not demonstrate cost-effectiveness in 32-35 wGA infants with ≤ 1 RF.

An evaluation of the emerging interventions against Respiratory Syncytial Virus (RSV)-associated acute lower respiratory infections in children

Background

Respiratory Syncytial Virus (RSV) is the leading cause of acute lower respiratory infections (ALRI) in children. It is estimated to cause approximately 33.8 million new episodes of ALRI in children annually, 96% of these occurring in developing countries. It is also estimated to result in about 53,000 to 199,000 deaths annually in young children. Currently there are several vaccine and immunoprophylaxis candidates against RSV in the developmental phase targeting active and passive immunization.

Methods

We used a modified CHNRI methodology for setting priorities in health research investments. This was done in two stages. In Stage I, we systematically reviewed the literature related to emerging vaccines against RSV relevant to 12 criteria of interest. In Stage II, we conducted an expert opinion exercise by inviting 20 experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies). The policy makers and industry representatives accepted our invitation on the condition of anonymity, due to the sensitive nature of their involvement in such exercises. They answered questions from the CHNRI framework and their “collective optimism” towards each criterion was documented on a scale from 0 to 100%.

Results

In the case of candidate vaccines for active immunization of infants against RSV, the experts expressed very low levels of optimism for low product cost, affordability and low cost of development; moderate levels of optimism regarding the criteria of answerability, likelihood of efficacy, deliverability, sustainability and acceptance to end users for the interventions; and high levels of optimism regarding impact on equity and acceptance to health workers. While considering the candidate vaccines targeting pregnant women, the panel expressed low levels of optimism for low product cost, affordability, answerability and low development cost; moderate levels of optimism for likelihood of efficacy, deliverability, sustainability and impact on equity; high levels of optimism regarding acceptance to end users and health workers. The group also evaluated immunoprophylaxis against RSV using monoclonal antibodies and expressed no optimism towards low product cost; very low levels of optimism regarding deliverability, affordability, sustainability, low implementation cost and impact on equity; moderate levels of optimism against the criteria of answerability, likelihood of efficacy, acceptance to end-users and health workers; and high levels of optimism regarding low development cost. They felt that either of these vaccines would have a high impact on reducing burden of childhood ALRI due to RSV and reduce the overall childhood ALRI burden by a maximum of about 10%.

Conclusion

Although monoclonal antibodies have proven to be effective in providing protection to high-risk infants, their introduction in resource poor settings might be limited by high cost associated with them. Candidate vaccines for active immunization of infants against RSV hold greatest promise. Introduction of a low cost vaccine against RSV would reduce the inequitable distribution of burden due to childhood ALRI and will most likely have a high impact on morbidity and mortality due to severe ALRI.

A decade of respiratory syncytial virus epidemiology and prophylaxis: translating evidence into everyday clinical practice

Respiratory syncytial virus (RSV) is a common infection in infancy, with nearly all children affected by two years of age. Approximately 0.5% to 2.0% of all children are hospitalized with lower respiratory tract disease, of which 50% to 90% have bronchiolitis and 5% to 40% have pneumonia. Morbidity and mortality are highest in children with nosocomial infection and in those with underlying medical illnesses such as cardiac and chronic lung disease. Aboriginal children residing in remote northern regions are specifically considered to be at high risk for hospitalization due to RSV infection. Thorough hand washing and health education are the principal strategies in primary prevention. In the absence of a vaccine, palivizumab prophylaxis is currently the best intervention to reduce the burden of illness and RSV-related hospitalization in high-risk children. Health care professionals should provide palivizumab prophylaxis cost effectively in accordance with recommendations issued by pediatric societies and national advisory bodies. The present article reviews the epidemiology of RSV infection and the short- and long-term impact of disease in high-risk infants and special populations. Prevention strategies and treatment are discussed based on the existing scientific evidence, and future challenges in the management of RSV infection are addressed.

Comparative costs of hospitalisation among infants at high risk for respiratory syncytial virus lower respiratory tract infection during the first year of life

OBJECTIVE

This retrospective cohort study compared the total cost of hospitalisation due to respiratory syncytial virus (RSV) lower respiratory tract infection (LRI) during the first year of life between late-preterm (33-36 weeks gestational age [wGA]) and term (≥ 37 wGA) infants.

RESEARCH DESIGN AND METHODS

A large national claims database of commercially insured members was examined to identify hospital admissions associated with RSV between January 2003 and June 2007 among infants at high risk for RSV LRI, including late-preterm infants. Hospital use and costs were compared with those of a reference cohort of term infants with RSV.

RESULTS

The cost of hospitalisation for RSV among late-preterm infants with at least one hospital admission associated with RSV (n=173) was twice that of term infants (n=1,983; $20,269 vs. 9,635; p< 0.001). The mean length of stay was also higher (5.3 vs. 3.4 days; p< 0.001). Approximately 21.9% of hospitalisations for late-preterm infants included an intensive care unit admission compared with 9.6% among term infants (p< 0.001).

LIMITATIONS

Reliance on ICD-9 codes to identify potential cohort members may result in misclassification and underreporting the cohort size for conditions of interest.

CONCLUSIONS

Hospitalisation costs and length of stay due to RSV LRI were significantly greater among late-preterm infants compared with term infants and higher than general estimates previously reported in the broader paediatric population.

The cost effectiveness of palivizumab: a systematic review of the evidence

OBJECTIVE

Palivizumab is a prophylactic therapy shown to reduce the number of respiratory syncytial virus (RSV)-related hospitalizations but has a high acquisition cost. The objective was to systematically examine the cost effectiveness of palivizumab in defined infant groups and identify important cost and outcome determinants.

METHODS

Literature searches of MedLine, the Cost-Effectiveness Analysis registry and the UK NHS Economic Evaluation Database (NHS EED) were conducted to identify economic evaluations of palivizumab compared to no prophylactic treatment for RSV prevention in any infant population. Study quality was evaluated using Quality of Health Economic Studies (QHES) criteria and results converted to 2009 CAN$ for comparison.

RESULTS

A total of 23 articles meeting inclusion criteria were identified, including 11 cost-utility analyses (CUAs) and 12 cost-effectiveness analyses (CEAs). Quality of individual analyses was fairly high (range 60-100, median 86). Results ranged from cost dominance for prophylaxis to $3,365,769/QALY depending on population, outcome measures, and input parameters. Base-case and sensitivity-analysis mortality rates varied between studies and influenced results.

CONCLUSIONS

RSV prophylaxis with palivizumab is cost effective in specific groups of high-risk infants, especially those with multiple environmental risk factors. Cost-effectiveness estimates vary between populations and settings and are more positive in those at highest risk for RSV hospitalization.

LIMITATIONS

Direct comparison of the published reports was limited by restriction to English language articles and the varied methodologies, input measures, and populations across the studies reviewed. Although reported currencies were converted to a common unit for comparison, this does not completely account for monetary and inflation differences.

Cost effectiveness of respiratory syncytial virus prophylaxis: a critical and systematic review

Respiratory syncytial virus (RSV) is the leading cause of infant hospitalization in the US. The economic burden of severe disease is substantial, including hospitalization costs and out-of-pocket expenses. RSV prophylaxis with either RSV immune globulin intravenous (RSV-IGIV) or palivizumab has been shown to be effective in reducing RSV-related hospitalizations. Motavizumab, a new enhanced-potency humanized RSV monoclonal antibody, is presently in clinical trials. RSV-IGIV and palivizumab are associated with high acquisition costs. Cost-effectiveness analyses are therefore of great importance in helping to determine who should receive RSV prophylaxis. Six studies have analysed the cost effectiveness of RSV-IGIV, 14 have analysed the cost effectiveness of palivizumab and five have analysed the cost effectiveness of both agents, two of which directly compared palivizumab with RSV-IGIV. The cost effectiveness of motavizumab has not been studied. Significant variation exists in the modelling used in these analyses. Many studies have examined short-term benefits such as reducing hospitalizations and associated costs, while fewer studies have examined long-term benefits such as QALYs or life-years gained. The payer and society have been the most common perspectives used. The endpoints examined varied and generally did not account for the potential impact of RSV prophylaxis on RSV-related complications such as asthma. While some studies have reported acceptable cost-effectiveness ratios for RSV prophylaxis, the majority failed to show cost savings or cost-effectiveness ratios below commonly accepted thresholds for either RSV-IGIV or palivizumab. Cost effectiveness of RSV prophylaxis tended to be more favourable in populations with specific risk factors, including premature infants < or =32 weeks' gestational age, and infants or children aged < 2 years with chronic lung disease or congenital heart disease. Comparing the results of economic analyses of the two agents suggests palivizumab may be the more cost-effective option in the population for which RSV prophylaxis is recommended. Over time, the acquisition cost of RSV prophylaxis agents, a major cost driver, may decrease, and more acceptable outcomes of economic analyses may result. Albeit important, the results of economic analyses are not the only tool that decision makers rely on, as population-specific risk factors, and efficacy and safety data must be considered when developing treatment guidelines and making clinical decisions.

Comparison of the cost of hospitalization for respiratory syncytial virus disease versus palivizumab prophylaxis in Canadian Inuit infants

BACKGROUND

The objectives were to compare actual respiratory syncytial virus (RSV) hospitalization rates and costs in a cohort of Inuit infants to hypothetical palivizumab prophylaxis strategies for infants of all gestational ages in the Eastern Canadian Arctic.

METHODS

Incidence and costs of RSV hospitalization were collected for infants admitted to the Baffin Regional Hospital in 2002, before the initiation of palivizumab. There was a comparison of the actual costs to the costs associated with 8 palivizumab strategies stratified by age (<6 months, <1 year) and location (overall, town [Iqaluit], rural communities). It was assumed that each category would receive universal palivizumab prophylaxis resulting in a 78% decrease in RSV admissions. The net costs incurred, number needed to treat (NNT), and incremental costs per hospitalization avoided were calculated for each comparison.

RESULTS

There was a great variation in the rates and costs associated with RSV admissions between Iqaluit and the communities. For infants <1 year of age residing in Iqaluit, the mean admission cost was $3915, and palivizumab prophylaxis had an NNT of 20.4 and cost of $162,551 per admission avoided. For rural infants <6 months, the mean cost of admission was $23,030, and palivizumab prophylaxis resulted in an NNT of 3.9 to 2.5 and cost savings of up to $8118 per admission avoided.

CONCLUSIONS

Due to the high rates and costs associated with RSV admissions, administration of palivizumab in rural communities in the Canadian Arctic to infants less than 6 months of age could result in net cost savings.

Barriers to generalizability of health economic evaluations in Latin America and the Caribbean region

Use and acceptance of health economic evaluations (HEEs) has been much greater in developed than in developing nations. Nevertheless, while developing countries lag behind in the development of HEE methods, they could benefit from the progress made in other countries and concentrate on ways in which existing methods can be used or would need to be modified to fulfill their specific needs. HEEs, as context-specific tools, are not easily generalizable from setting to setting. Existing studies regarding generalizability and transferability of HEEs have primarily been conducted in developed countries. Therefore, a legitimate question for policy makers in Latin America and the Caribbean region (LAC) is to what extent HEEs conducted in industrialized economies and in LAC are generalizable to LAC (trans-regional) and to other LAC countries (intra-regional), respectively. We conducted a systematic review, searching the NHS Economic Evaluation Database (NHS EED), Office of Health Economics Health Economic Evaluation Database (HEED), LILACS (Latin America health bibliographic database) and NEVALAT (Latin American Network on HEE) to identify HEEs published between 1980 and 2004. We included individual patient- and model-based HEEs (cost-effectiveness, cost-utility, cost-benefit and cost-consequences analyses) that involved at least one LAC country. Data were extracted by three independent reviewers using a checklist validated by regional and international experts. From 521 studies retrieved, 72 were full HEEs (39% randomized controlled trials [RCTs], 32% models, 17% non-randomized studies and 12% mixed trial-modeling approach). Over one-third of identified studies did not specifically report the type of HEE. Cost-effectiveness and cost-consequence analyses accounted for almost 80% of the studies. The three Latin American countries with the highest participation in HEE studies were Brazil, Argentina and Mexico. While we found relatively good standards of reporting the study's question, population, interventions, comparators and conclusions, the overall reporting was poor, and evidence of unfamiliarity with international guidelines was evident (i.e. absence of incremental analysis, of discounting long-term costs and effects). Analysis or description of place-to-place variability was infrequent. Of the 49 trial-based analyses, 43% were single centre, 33% multinational and 18% multicentre national. Main reporting problems included issues related to sample representativeness, data collection and data analysis. Of the 32 model-based studies (most commonly using epidemiological models), main problems included the inadequacy of search strategy, range selection for sensitivity analysis and theoretical justifications. There are a number of issues associated with the reporting and methodology used in multinational and local HEE studies relevant for LAC that preclude the assessment of their generalizability and potential transferability. Although the quality of reporting and methodology used in model-based HEEs was somewhat higher than those from trial-based HEEs, economic evaluation methodology was usually weak and less developed than the analysis of clinical data. Improving these aspects in LAC HEE studies is paramount to maximizing their potential benefits such as increasing the generalizability/transferability of their results.

Respiratory syncytial virus prophylaxis in a high-risk population in Argentina: a cost-effectiveness analysis

Palivizumab has proved effective in reducing hospitalization rates because of respiratory syncytial virus in vulnerable groups. In Argentina its administration is not universal because of high costs. We made a cohort study and enrolled 159 children who met the American Academy of Pediatrics recommendations but did not receive palivizumab; 26% required hospitalization for respiratory syncytial virus infection. Siblings and bronchopulmonary dysplasia were associated with higher hospitalization. For high-risk patients, one averted hospitalization was associated with costs of U.S. dollars (USD)13, 198 [number needed to treat (NNT): 4.5].

Differential gender response to respiratory infections and to the protective effect of breast milk in preterm infants

OBJECTIVE

The protective role of breastfeeding against severe acute lung disease in infants is well established, but its mechanism is unclear. Most hypotheses assume that breastfeeding confers similar passive protection to every infant; however, a few observations have suggested that the benefits of breast milk against severe lung disease may differ according to gender. The objective of this study was to determine whether the effect of breastfeeding on susceptibility to severe acute lung disease among infants at high risk is different for girls and boys.

METHODS

A cohort was analyzed prospectively by use of 2 different strategies: (1) predictors of first episode of rehospitalization by univariate and multivariate analyses using robust Poisson regression and (2) mean number of rehospitalizations between groups using multiple regression negative binomial models.

RESULTS

A total of 119 high-risk, very low birth weight infants were enrolled. Breast milk protected girls but not boys against severe acute lung disease. The interaction between breastfeeding and gender was clinically and statistically significant, even after adjustment for variables that can affect severity of acute lung disease. Disease was most severe in formula-fed girls (versus formula-fed boys).

CONCLUSIONS

Breastfeeding decreased the risk for severe acute lung disease in girls but not in boys. These findings suggest that breast milk protection is not universally conferred by passive transfer of humoral immunity (which should be gender indifferent), show that respiratory symptoms may be amenable to nonspecific modulation, and identify nonbreastfed preterm infant girls as an at-risk group for severe acute lung disease.

Cost, causes and rates of rehospitalization of preterm infants

OBJECTIVE

To examine hospital readmissions for premature infants during the first year of life.

STUDY DESIGN

The California maternal and newborn/infant hospital discharge records were examined for subsequent readmission during the first year of life for all newborns from 1992 to 2000. Discharge diagnoses, hospital days, demographic data and hospital charges for infants born preterm (<36 weeks gestation) were identified and evaluated.

RESULT

About 15% of preterm infants required at least one rehospitalization within the first year of life (average cost per readmission 8,468 dollars, average annual cost in excess of 41 million dollars). Infants with gestational age <25 weeks had the highest rate of readmission (31%) and longest average length of stay (12 hospital days). The largest cohort, infants born at 35 weeks gestation, had the highest total cost of readmission (92.9 million dollars). The most common cause of rehospitalization was acute respiratory disease. There was no decrease in the number or cost of readmissions of premature infants for respiratory syncytial virus infections following the introduction of palivizumab in 1998.

CONCLUSION

After initial discharge, premature infants continue to have significant in-patient health-care needs and costs.

Reliability of medicaid claims versus medical record data: in a cost analysis of palivizumab

BACKGROUND

Palivizumab is one of the most costly paediatric medications for Medicaid and other health plans. It is uncertain whether the costs of palivizumab administration are justified in specific risk groups. Ongoing investigations of palivizumab require identification of reliable data sources.

OBJECTIVE

To estimate the reliability between Medicaid paid claims data and medical records documentation in a cost analysis of palivizumab.

STUDY DESIGN

A cross-sectional study of data reliability was performed within a cost analysis study of palivizumab in a cohort of at-risk patients during the US 2002/3 respiratory syncytial virus season. Exposure classification (to palivizumab prophylaxis) was compared using Medicaid claims and medical records data.

METHODS

The study was performed in 28 widely dispersed paediatric medical practices serving North Carolina, USA Medicaid patients within the AccessCare/Community Care of North Carolina (CCNC) Program, an enhanced primary care case management programme. Patients were eligible if they were born between 1 March 2002 and 28 February 2003 at 32-35 weeks estimated gestational age, were enrolled in the North Carolina primary care case management Medicaid programme during the study period and were patients of the participating practices. Medicaid healthcare claims were obtained in December 2003 for services provided between October 2002 and May 2003. Medical records were abstracted by community-based case managers. Primary variables included frequency, dates and dose of palivizumab injections. The main outcomes measures were agreement in the number of palivizumab injections, dates of administration and doses of palivizumab between Medicaid paid claims and medical record data.

RESULTS

Injection frequencies matched between medical record and Medicaid claims data for only 46.2% of study participants. Congruence in injection service dates occurred between data sources for only 1% of injections. Doses were similar between data sources for 81.9% of injections.

CONCLUSIONS

In Medicaid recipients receiving palivizumab injection, Medicaid claims data were inconsistent with medical records data. Use of multiple data sources and validation are recommended to identify temporal relationships between drug administration and endpoints of interest.

Quality Assessment of Published Health Economic Analyses from South America

Background:

Health economic analyses have become important to healthcare systems worldwide. No studies have previously examined South America's contribution in this area.

Objective:

To survey the literature with the purpose of reviewing, quantifying, and assessing the quality of published South American health economic analyses.

Methods:

A search of MEDLINE (1990–December 2004), EMBASE (1990–December 2004), International Pharmaceutical Abstracts (1990–December 2004), Literatura Latino-Americana e do Caribe em Ciências da Saûde (1982–December 2004), and Sistema de Informacion Esencial en Terapéutica y Salud (1980–December 2004) was completed using the key words cost-effectiveness analysis (CEA), cost-utility analysis (CUA), cost-minimization analysis (CMA), and cost-benefit analysis (CBA); abbreviations CEA, CUA, CMA, and CBA; and all South American country names. Papers were categorized by type and country by 2 independent reviewers. Quality was assessed using a 12 item checklist, characterizing scores as 4 (good), 3 (acceptable), 2 (poor), 1 (unable to judge), and 0 (unacceptable). To be included in our investigation, studies needed to have simultaneously examined costs and outcomes.

Results:

We retrieved 25 articles; one duplicate article was rejected, leaving 24 (CEA = 15, CBA = 6, CMA = 3; Brazil = 9, Argentina = 5, Colombia = 3, Chile = 2, Ecuador = 2, 1 each from Peru, Uruguay, Venezuela). Variability between raters was less than 0.5 point on overall scores (OS) and less than 1 point on all individual items. Mean OS was 2.6 (SD 1.0, range 1.4–3.8). CBAs scored highest (OS 2.8, SD 0.8), CEAs next (OS 2.7, SD 0.7), and CMAs lowest (OS 2.0, SD 0.5). When scored by type of question, definition of study aim scored highest (OS 3.0, SD 0.8), while ethical issues scored lowest (OS 1.5, SD 0.9). By country, Peru scored highest (mean OS 3.8) and Uruguay had the lowest scores (mean OS 2.2). A nonsignificant time trend was noted for OS (R2 = 0.12; p = 0.104).

Conclusions:

Quality scores of health economic analyses articles published in South America were rated poor to acceptable and lower than previous research from other countries. Thus, efforts are needed to improve the reporting quality of these analyses in South America. Future research should examine the region's level of expertise and educational opportunities for those in the field of health economics.

Community-based interventions for improving perinatal and neonatal health outcomes in developing countries: a review of the evidence

BACKGROUND

Infant and under-5 childhood mortality rates in developing countries have declined significantly in the past 2 to 3 decades. However, 2 critical indicators, maternal and newborn mortality, have hardly changed. World leaders at the United Nations Millennium Summit in September 2000 agreed on a critical goal to reduce deaths of children <5 years by two thirds, but this may be unattainable without halving newborn deaths, which now comprise 40% of all under-5 deaths. Greater emphasis on wide-scale implementation of proven, cost-effective measures is required to save women's and newborns' lives. Approximately 99% of neonatal deaths take place in developing countries, mostly in homes and communities. A comprehensive review of the evidence base for impact of interventions on neonatal health and survival in developing-country communities has not been reported.

OBJECTIVE

This review of community-based antenatal, intrapartum, and postnatal intervention trials in developing countries aimed to identify (1) key behaviors and interventions for which the weight of evidence is sufficient to recommend their inclusion in community-based neonatal care programs and (2) key gaps in knowledge and priority areas for future research and program learning.

METHODS

Available published and unpublished data on the impact of community-based strategies and interventions on perinatal and neonatal health status outcomes were reviewed. Evidence was summarized systematically and categorized into 4 levels of evidence based on study size, location, design, and reported impact, particularly on perinatal or neonatal mortality. The evidence was placed in the context of biological plausibility of the intervention; evidence from relevant developed-country studies; health care program experience in implementation; and recommendations from the World Health Organization and other leading agencies.

RESULTS

A paucity of community-based data was found from developing-country studies on health status impact for many interventions currently being considered for inclusion in neonatal health programs. However, review of the evidence and consideration of the broader context of knowledge, experience, and recommendations regarding these interventions enabled us to categorize them according to the strength of the evidence base and confidence regarding their inclusion now in programs. This article identifies a package of priority interventions to include in programs and formulates research priorities for advancing the state of the art in neonatal health care.

CONCLUSIONS

This review emphasizes some new findings while recommending an integrated approach to safe motherhood and newborn health. The results of this study provide a foundation for policies and programs related to maternal and newborn health and emphasizes the importance of health systems research and evaluation of interventions. The review offers compelling support for using research to identify the most effective measures to save newborn lives. It also may facilitate dialogue with policy makers about the importance of investing in neonatal health.

Hospital admission of high risk infants for respiratory syncytial virus infection: implications for palivizumab prophylaxis

OBJECTIVES

To determine the rates of hospital admission for respiratory syncytial virus (RSV) infection among children born at different gestational ages. To assess the theoretical impact of palivizumab prophylaxis on admissions for RSV infection.

DESIGN

Retrospective cohort study of children born in 1991-2000.

SETTING

Tertiary care university hospital.

METHODS

Data on all children born during the 10 year period were combined with information on laboratory confirmed RSV infections in these children until the end of 2002. The theoretical impact of palivizumab on RSV associated admissions was estimated by applying the current recommendations for prophylaxis to the study population and using the observed rates of admission in the calculations.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Rates of RSV infection and hospital admission in different subgroups of children.

RESULTS

Children with chronic lung disease (CLD) were admitted for RSV infection at a rate of 12.0%. The corresponding rates in children born at </=28 or 29-32 weeks gestation were 7.1% and 6.8% respectively. Children born at </=32 weeks gestation accounted for 6.6% of all admissions due to RSV. Of 586 children who would have met the criteria for palivizumab prophylaxis, 27 (4.6%) were admitted with RSV during the presumed prophylactic period. The number needed to treat to prevent one admission for RSV infection was 15 for children with CLD (with a total cost of 75 000) and 43 for children without CLD born at </=32 weeks gestation (with a total cost of 215 000).

CONCLUSIONS

The rates of hospital admission for RSV infection in premature infants were substantially lower than those in most previous reports from other countries. Determination of the local rates of RSV admissions in different groups of children would be useful in making decisions about the use of palivizumab.

Direct cost analyses of palivizumab treatment in a cohort of at-risk children: evidence from the North Carolina Medicaid Program

OBJECTIVE

Use of palivizumab prophylactic therapy reduces the occurrence of hospitalizations for serious respiratory syncytial virus (RSV) lower respiratory tract infections in at-risk infants. The direct cost-benefit of palivizumab prophylaxis for infants who are born at 32 to 35 weeks' estimated gestational age (EGA) during their first year of life has not been systematically examined. The objective of this study was to compare the direct costs of palivizumab prophylaxis and RSV treatment in infants who were born at 32 to 35 weeks EGA and received and did not receive palivizumab.

METHODS

A cohort study was performed of infants who were younger than 1 year and were enrolled in an enhanced primary care case management model within the North Carolina Medicaid Program. Comparisons were made between infants who received (Synagis prophylaxis group) and did not receive palivizumab (nonprophylaxis group) during the study period. Cost was examined using the sum of Medicaid paid services for prophylaxis with palivizumab and treatment for RSV infections that occurred between October 1, 2002, and May 31, 2003. The Anderson framework was used to specify the regression cost models to compare the participants who received (Synagis prophylaxis) and did not receive (nonprophylaxis group) palivizumab. The primary outcomes were actual 7-month seasonal costs and standardized seasonal costs adjusting for the varied months of infant participation.

RESULTS

The study sample included 185 Synagis prophylaxis and 182 nonprophylaxis participants who met the inclusion criteria. The average per-person total cost of RSV care and prophylaxis was 5117 dollars for the Synagis prophylaxis group and 371 dollars for the nonprophylaxis group. Five hospitalizations occurred in the prophylaxis group, and 12 occurred in the nonprophylaxis group (odds ratio: 0.27). No deaths occurred in either group.

CONCLUSIONS

Palivizumab administered to infants who were born at 32 to 35 weeks' EGA did not provide direct cost savings related to hospitalization or ambulatory care in a Medicaid population. The primary difference in cost between the groups was attributable to the palivizumab prophylaxis.

Anticipated costs of hospitalization for respiratory syncytial virus infection in young children at risk

BACKGROUND

Reliable estimates of hospitalization costs for severe respiratory syncytial virus (RSV) infection are necessary to perform economic analyses of preventive strategies of severe RSV disease. We aimed to develop a model that predicts anticipated mean RSV hospitalization costs of groups of young children at risk for hospitalization, but not yet hospitalized, based on readily available child characteristics.

METHODS

We determined real direct medical costs of RSV hospitalization from a societal perspective, using a bottom-up strategy, in 3458 infants and young children hospitalized for severe RSV disease during the RSV seasons 1996-1997 to 1999-2000 in the Southwest of the Netherlands. We used a linear regression model to predict anticipated mean RSV hospitalization costs of groups of children at risk, based on 4 child characteristics [age, gestational age, birth weight and bronchopulmonary dysplasia (BPD)], expressed in EC Euros as of the year 2000.

FINDINGS

The mean RSV hospitalization costs of all patients were 3110 Euros. RSV hospitalization costs were higher for patients with lower gestational age (5555 Euros; gestational age, </=28 weeks), lower birth weight (3895 Euros; birth weight </=2500 g), BPD (5785 Euros; with BPD) and young age (4730 Euros; first month of life). The linear regression model had an adjusted R of 0.08. This indicates a low explanatory ability for hospitalization costs of individual children. However, the model could accurately estimate the anticipated mean hospitalization costs of groups of children with the same characteristics.

INTERPRETATION

RSV hospitalization costs were substantial, especially of specific high risk groups. Anticipated mean hospitalization costs of groups of children at risk for RSV hospitalization, but not yet hospitalized, could well be estimated with 4 child characteristics (age, gestational age, birth weight and BPD). These estimated costs can be used for economic analyses of preventive strategies for severe RSV disease.

Current strategies in the prevention of respiratory syncytial virus disease

Infants infected with respiratory syncytial virus (RSV) develop both upper and lower respiratory tract infections resulting in laryngotracheobronchitis, bronchiolitis and pneumonia. Premature infants of less than 32 weeks' gestation and those with underlying chronic lung disease are particularly susceptible and incur significant morbidity and mortality following hospitalisation. Conservative RSV prevention strategies focus on the interruption of transmission by proper hand-washing techniques and reducing exposure to potential environmental risk factors. Major challenges have impeded the development of an RSV vaccine but a licensed product may be expected in the near future. Prophylaxis with a humanised mouse monoclonal antibody (palivizumab) has been effective in reducing the rate of RSV hospitalisation in high-risk premature infants in phase II-IV trials and is available for use within internationally approved guidelines. Experimental studies evaluating the use of palivizumab in patients with congenital heart disease, those with cystic fibrosis and immunosuppressed bone marrow transplant recipients are well underway, the results of which are eagerly awaited.

Impacto potencial y análisis coste-eficacia de la profilaxis con palivizumab, en la prevención de bronquiolitis, en prematuros menores de 33 semanas de gestación

INTRODUCTION

Respiratory syncytial virus (RSV) is the main cause of bronchiolitis in children aged less than 2 years. The effectiveness of palivizumab has recently been reported in several clinical trials.

OBJECTIVE

The aim of this study was to evaluate the hypothetical impact of a treatment strategy using palivizumab for the prevention of bronchiolitis in premature infants.

METHODS

Neonates born in our hospital between January 1995 and December 1998 who were admitted for bronchiolitis were included. Using information from the Impact-RSV study, the effects and impact of different cut-off points in the gestational age of the study group were measured. Cost-effectiveness analysis included the cost of hospitalization as well as the direct cost of palivizumab prescriptions.

RESULTS

Of 7,766 newborn infants, 56 had a gestational age of < or =32 weeks. Of these, bronchiolitis was diagnosed in eight infants (14.28%), and RSV was isolated in seven (14.28%). After hypothetical prophylaxis in premature infants the best results were obtained in the group with a gestational age of 30 weeks. In this group the relative risk of admission for bronchiolitis was 12.1 (95% CI: 4.8-30.5) and treatment would be required in nine infants to avoid one admission (cost Euros 12,915), with a cost 3.8 times greater than the current cost, without prophylaxis.

CONCLUSIONS

Measurement of the impact and cost-effectiveness analysis of palivizumab prophylaxis provides a useful method for determining recommendations for the prevention of bronchiolitis in premature infants.

Acute viral bronchiolitis and its sequelae in developing countries

Acute viral bronchiolitis (AVB) is a common disease found throughout the world. Various aspects of it are being studied: its epidemiology, diagnosis, prognosis and treatment. Most of these studies are being conducted in developed countries, with only a few taking place in developing countries. Risk factors such as poor nutrition, an adverse environment and early weaning should be studied where these features are common. Treatment aspects such as cost-effectiveness in low income settings need further study. Use of ribavirin and respiratory syncytial virus (RSV)-immunoglobulin are good examples. Post-bronchiolitic sequelae also need to be studied in low income countries. There is evidence that bronchiolitis obliterans is unusually frequent in some Latin-American countries such as Argentina and Brazil. It will be helpful to undertake combined studies in countries with the same socio-economics, investigating the preventive and management aspects of AVB and its sequelae to reduce the morbidity and mortality.