Cost-effectiveness of respiratory syncytial virus prophylaxis with palivizumab

Adherence to the 2014 American Academy of Pediatrics palivizumab prophylaxis recommendations

INTRODUCTION

This study aims to describe adherence rates to the 2014 American Academy of Pediatrics (AAP) Committee on Infectious Disease guidance document recommending which patients should receive palivizumab for prophylaxis against respiratory syncytial virus (RSV).

METHODS

A retrospective, single-center analysis of patients who received at least one dose of palivizumab between October 1, 2012, and March 1, 2017 was conducted. Data collected included demographics, medical history, palivizumab administration regimens, and incidence of RSV infection.

RESULTS

Data were collected on 457 patients who received palivizumab over five RSV seasons. Approximately half of the patients (45% and 55%, respectively) received palivizumab according to the AAP recommendations in place at the time (2012 or 2014 recommendations, respectively). One percent of patients had a breakthrough RSV infection after receiving at least one dose of palivizumab. There was no significant difference in the number of breakthrough infections before and after the 2014 recommendations were released (3 vs. 2).

CONCLUSIONS

Approximately half of the patients received prophylaxis in accordance with the 2014 AAP recommendations and infrequently suffered from a breakthrough RSV infection.

Cost of Respiratory Syncytial Virus-Associated Acute Lower Respiratory Infection Management in Young Children at the Regional and Global Level: A Systematic Review and Meta-Analysis

Background

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infection (ALRI) in young children aged <5 years.

Methods

We aimed to identify the global inpatient and outpatient cost of management of RSV-ALRI in young children to assist health policy makers in making decisions related to resource allocation for interventions to reduce severe morbidity and mortality from RSV in this age group. We searched 3 electronic databases including Global Health, Medline, and EMBASE for studies reporting cost data on RSV management in children under 60 months from 2000 to 2017. Unpublished data on the management cost of RSV episodes were collected through collaboration with an international working group (RSV GEN) and claim databases.

Results

We identified 41 studies reporting data from year 1987 to 2017, mainly from Europe, North America, and Australia, covering the management of a total of 365 828 RSV disease episodes. The average cost per episode was €3452 (95% confidence interval [CI], 3265–3639) and €299 (95% CI, 295–303) for inpatient and outpatient management without follow-up, and it increased to €8591(95% CI, 8489–8692) and €2191 (95% CI, 2190–2192), respectively, with follow-up to 2 years after the initial event.

Conclusions

Known risk factors (early and late preterm birth, congenital heart disease, chronic lung disease, intensive care unit admission, and ventilator use) were associated with €4160 (95% CI, 3237–5082) increased cost of hospitalization. The global cost of inpatient and outpatient RSV ALRI management in young children in 2017 was estimated to be approximately €4.82 billion (95% CI, 3.47–7.93), 65% of these in developing countries and 55% of global costs accounted for by hospitalization. We have demonstrated that RSV imposed a substantial economic burden on health systems, governments, and the society.

Severe Respiratory Syncytial Virus Infection in Hospitalized Children Less Than 3 Years of Age in a Temperate and Tropical Climate

BACKGROUND

Respiratory syncytial virus (RSV) infection is a frequent cause of hospitalization in infants younger than 3 years of age. We aimed to determine the factors associated with severe RSV disease.

METHODS

Retrospective medical review of children up to 3 years of age admitted for laboratory-proven RSV infection between January 1, 2013, and December 31, 2014, was conducted at the Women's and Children's Hospital, Adelaide, South Australia, and the Paediatric Department at Cairns Hospital, Cairns, North Queensland. Severity of infection was determined using the validated Brisbane RSV Infection Severity Score.

RESULTS

Four-hundred ninety-six children (383 at Women's and Children's Hospital and 113 at Cairns Hospital) were included in the study, with 76, 323 and 97 patients identified as having mild, moderate or severe disease, respectively. Decreasing age [odds ratio (OR) = 0.95; 95% confidence interval (CI) = 0.90-0.99, P = 0.020), and being Indigenous, increased (OR = 2.6; 95% CI = 1.4-4.9, P = 0.002) the risk of severe RSV infection in hospitalized children. Underlying respiratory (P = 0.029, OR = 2.5; 95% CI = 1.1-5.8) or cardiac (OR = 2.7; 95% CI = 1.1-6.4, P = 0.024) conditions, as well as the presence of tachypnoea on admission (OR = 2.2; 95% CI = 1.2-4.1, P = 0.009), were also independent predictors of severe RSV infection. Seasonal variation in hospitalization was observed between temperate and tropical climates but was not associated with disease severity.

CONCLUSIONS

Young infants, Indigenous patients and children with underlying respiratory and cardiac disease should be observed closely for signs of deterioration. Infants with tachypnoea on admission should be continuously monitored.

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.

Cost-effectiveness of palivizumab compared to no prophylaxis in term infants residing in the Canadian Arctic

BACKGROUND

Hospital admissions for respiratory syncytial virus infection result in large health expenditures for Inuit infants. Palivizumab has been shown to be highly effective in reducing such admissions in preterm Inuit infants. We performed a cost-effectiveness analysis estimating the incremental cost-effectiveness ratio (ICER) for palivizumab prophylaxis per admission related to respiratory syncytial virus avoided in healthy term infants across the Canadian Arctic.

METHODS

We compared universal palivizumab prophylaxis in term infants less than 6 months of age to no prophylaxis in 8 Arctic regions: the Northwest Territories, Nunavut, Nunavut without Iqaluit, the 3 subregions of Nunavut (Kitikmeot, Kivalliq and Qikiqtaaluk), the Qikiqtaaluk Region without Iqaluit, and Nunavik (northern Quebec). Costs were acquired from the territorial governments, hospitals and contracted agencies. The perspective is that of the public payer, with a 6-month timeline. In scenario A, universal prophylaxis was provided until the end of the respiratory syncytial virus season, and in scenario B, infants received prophylaxis until 5 months of age. The ICERs of scenario A were compared with those of scenario B.

RESULTS

Under scenario A, the cost per admission avoided was as high as $546 115 in the Northwest Territories, compared with a cost savings of $36 145 in the Kitikmeot Region. Under scenario B, the ICER showed cost savings of $48 549 in the Kitikmeot Region and $2731 in the Kivalliq Region, with low ICERs in Nunavik of $15 601.

INTERPRETATION

Considerable cost savings were found for the Kitikmeot Region with universal palivizumab prophylaxis in term infants with both scenarios, whereas cost savings were found for the Kivalliq Region with scenario B. Stopping prophylaxis at 5 months of age was a more cost-effective strategy in all regions except the Kitikmeot Region. Nunavik had low ICERs, and prophylaxis should be considered for this region.

Respiratory syncytial virus seasonality in tropical Australia

OBJECTIVE

Respiratory syncytial virus (RSV) is most common during the rainy season in a number of low- to middle-income tropical settings, a pattern driven by seasonal changes in climate and nutrition. We investigated the seasonality of RSV in the high-income tropical setting of North Queensland, Australia.

METHODS

We used RSV hospital admissions data from Cairns and Townsville to assess the seasonality of RSV. We examined the seasonal scale associations between selected meteorological exposures and RSV admissions using cross-correlation of weekly data.

RESULTS

In both Cairns and Townsville, RSV admissions were highest in the latter half of the rainy season. In Cairns, RSV admissions were most strongly correlated with rainfall four weeks previously. In Townsville, RSV admissions were most strongly correlated with rainfall six weeks previously.

CONCLUSIONS

The seasonality of RSV in the tropical setting of North Queensland appears to be driven by seasonal variations in rainfall. Further research is needed to assess the impact of climate on RSV incidence in the tropics.

Global systematic review of the cost-effectiveness of indigenous health interventions

BACKGROUND

Indigenous populations around the world have consistently been shown to bear a greater burden of disease, death and disability than their non-Indigenous counterparts. Despite this, little is known about what constitutes cost-effective interventions in these groups. The objective of this paper was to assess the global cost-effectiveness literature in Indigenous health to identify characteristics of successful and unsuccessful interventions and highlight areas for further research.

METHODS AND FINDINGS

A systematic review of the published literature was carried out. MEDLINE, PSYCINFO, ECONLIT, EMBASE and CINAHL were searched with terms to identify cost-effectiveness evaluations of interventions in Indigenous populations around the world. The WHO definition was followed in identifying Indigenous populations. 19 studies reporting on 27 interventions were included in the review. The majority of studies came from high-income nations with only two studies of interventions in low and middle-income nations. 22 of the 27 interventions included in the analysis were found to be cost-effective or cost-saving by the respective studies. There were only two studies that focused on Indigenous communities in urban areas, neither of which was found to be cost-effective. There was little attention paid to Indigenous conceptions of health in included studies. Of the 27 included studies, 23 were interventions that specifically targeted Indigenous populations. Outreach programs were shown to be consistently cost-effective.

CONCLUSION

The comprehensive review found only a small number of studies examining the cost-effectiveness of interventions into Indigenous communities around the world. Given the persistent disparities in health outcomes faced by these populations and commitments from governments around the world to improving these outcomes, it is an area where the health economics and public health fields can play an important role in improving the health of millions of people.

Palivizumab prophylaxis during nosocomial outbreaks of respiratory syncytial virus in a neonatal intensive care unit: predicting effectiveness with an artificial neural network model

STUDY OBJECTIVE

To identify subgroups of premature infants who may benefit from palivizumab prophylaxis during nosocomial outbreaks of respiratory syncytial virus (RSV) infection.

DESIGN

Retrospective analysis using an artificial intelligence model.

SETTING

Level IIIB, 35-bed, neonatal intensive care unit (NICU) at a tertiary care hospital in the United Arab Emirates.

PATIENTS

One hundred seventy six premature infants, born at a gestational age of 22-34 weeks, and hospitalized during four RSV outbreaks that occurred between April 2005 and July 2007.

MEASUREMENTS AND MAIN RESULTS

We collected demographic and clinical data for each patient by using a standardized form. Input data consisted of seven categoric and continuous variables each. We trained, tested, and validated artificial neural networks for three outcomes of interest: mortality, days of supplemental oxygen, and length of NICU stay after the index case was identified. We compared variable impacts and performed reassignments with live predictions to evaluate the effect of palivizumab. Of the 176 infants, 31 (17.6%) received palivizumab during the outbreaks. All neural network configurations converged within 4 seconds in less than 400 training cycles. Infants who received palivizumab required supplemental oxygen for a shorter duration compared with controls (105.2 ± 7.2 days vs 113.2 ± 10.4 days, p=0.003). This benefit was statistically significant in male infants whose birth weight was less than 0.7 kg and who had hemodynamically significant congenital heart disease. Length of NICU stay after identification of the index case and mortality were independent of palivizumab use.

CONCLUSION

Palivizumab may be an effective intervention during nosocomial outbreaks of RSV in a subgroup of extremely low-birth-weight male infants with hemodynamically significant congenital heart disease.

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.

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.

Impact of respiratory syncytial virus: the nurse's perspective

Respiratory syncytial virus (RSV) is a highly contagious virus, and is the major cause of lower respiratory tract infections in infants and toddlers worldwide. RSV infection poses serious health risks to young children during the first 2 years of life. Several infant populations have been classified as high risk, and additional risk factors are known to increase the likelihood of severe RSV infection. Treatment for active RSV infection is limited to the symptoms of infection rather than the underlying cause; therefore, it is critical to reduce the transmission of RSV. As nurses, we highlight the importance of educating healthcare professionals, both in the hospital and community settings, as well as parents and other caregivers about the risks and outcomes associated with RSV infection, and necessary measures to decrease the risk of infection. We also highlight the importance of the successful identification of those children who are at high risk of RSV infection. RSV prophylaxis (RSVP) with palivizumab has been shown to improve clinical outcome in infants who are considered high risk compared with those who have not received RSVP. The failure of healthcare staff and primary caregivers to protect children against an RSV infection can have lasting detrimental effects on the health and lives of affected children and their families.

Economic evaluation of palivizumab in children with congenital heart disease: a Canadian perspective

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of bronchiolitis in infants. In children with congenital heart disease (CHD), it is associated with significant morbidity and mortality. Palivizumab is a monoclonal antibody that reduces the number of RSV-associated hospitalizations in children with CHD. We sought to assess cost savings and cost-effectiveness of palivizumab in children < 2 years old with hemodynamically significant CHD in a provincially administered RSV prophylaxis program.

METHODS

A cohort of children who received palivizumab (N = 292) from 2003-2007 was compared to a historical cohort of children (N = 412) from 1998-2003 who met the eligibility criteria for palivizumab prior to initiation of the prophylaxis program. Direct and indirect costs and benefits were determined.

RESULTS

The direct and indirect costs in the historical cohort were $838 per patient season compared to $9130 per patient season in the palivizumab cohort. Risk of admission was reduced by 42%, and days in hospital were reduced by 83%. The incremental cost of the RSV prophylaxis program was $8292 per patient for 1 RSV season. The incremental cost to prevent 1 day of hospitalization was $15,514. The cost of palivizumab accounted for 87.9% of the cost of prophylaxis.

CONCLUSIONS

Palivizumab is clinically effective; however, the cost was exceptionally high relative to the outcomes in this population. Given the financial constraints in a public health care setting, more strict criteria for patient selection or reduced drug costs would improve the cost-effectiveness of RSV prophylaxis.

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.

Respiratory syncytial virus infections in Central Australia

BACKGROUND

Little is known about the epidemiology of respiratory syncytial virus (RSV) infection in arid desert regions and in the Aboriginal population. We describe the seasonality and epidemiology of RSV infection in Central Australia, an arid area with a large Aboriginal population.

METHODS

Five-year retrospective study from 2000 through 2004 of children less than 2 years old admitted to Alice Springs Hospital with documented RSV infection.

RESULTS

RSV infection was documented in 173 children <2 years old admitted over a 5-year period, 165 community-acquired and 8 nosocomial. The annual incidence rate of community-acquired RSV infection in hospitalised Central Australian children <2 years old was 20.4 per 1000. The rate in Aboriginal children of 29.6 per 1000 children was significantly greater than in non-Aboriginal children of 10.9 per 1000 (P < 0.0001). Associated risk factors were common; 52% of infected children had at least one other comorbidity. Younger children had more severe illness and longer duration of hospital stay. RSV-related illness peaked in winter but infections occurred throughout the year, and the winter predominance was less marked than in temperate climates.

CONCLUSIONS

In the arid, desert region of Central Australia, RSV infection occurs throughout the year, but is more frequent in winter and more common in Aboriginal children. These data are important for understanding RSV epidemiology in desert regions, and for planning active or passive RSV immunoprophylaxis in these and other similar populations.

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.

Prevention of respiratory syncytial virus infection

Respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract infection in young children, with significant numbers of premature infants and those with other risk factors requiring hospitalization in Canada each year. Palivizumab, an RSV-specific monoclonal antibody, can reduce the hospitalization rate and severity of illness for a small group of high-risk or premature infants during their first RSV season. The present statement reviews the published literature and provides recommendations regarding its use in premature and other at-risk infants, for Canadian physicians.

The influence over a period of 8 years of patterns of prescribing palivizumab for patients with and without congenitally malformed hearts, and in admissions to paediatric intensive care

OBJECTIVES

To describe the pattern of prescribing for palivizumab in the Glasgow area over the period 1999 through 2007, and to compare recent prescribing to the current recommendations by the Joint Committee on Vaccination and Immunisation of the United Kingdom Department of Health. Our secondary objective was to describe admissions to paediatric intensive care in patients with respiratory syncytial virus receiving palivizumab.

SETTING

Tertiary children's hospital out-patient immunisation clinic and paediatric intensive care unit.

DESIGN

Prospective analysis of prescribing and admissions data for the period 1999 through 2007.

OUTCOME MEASURES

Number of prescriptions and admissions to the paediatric intensive care unit.

RESULTS

The number of children receiving palivizumab annually initially rose more than 5-fold, from 17 in the season of 1999 and 2000 versus 115 in 2004 and 2005, although it has declined in the past 2 years, to 63 in 2006 and 2007, following publication of the recommendations of the Joint Committee on Vaccination and Immunisation established by the United Kingdom Department of Health. There has been no significant change in demographics of patients during this period. Prior to publication of these recommendations, 35 of 44 (80%) patients with congenitally malformed hearts who received palivizumab in the season of 2005 and 2006 deviated from the current recommendations, compared to 5 of 51 (10%) who received palivizumab for non-cardiac indications. No patients who received palivizumab required admission to the paediatric intensive care unit with proven respiratory syncytial virus infection over the 8 year period.

CONCLUSIONS

The number of children receiving palivizumab initially increased significantly, although it has now fallen following implementation of national recommendations. Much prescribing, particularly for children with congenitally malformed hearts, did not fulfil current recommendations. The absence of admissions to paediatric intensive care reflects the success of targeted immunisation in our population.

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.

Prospective population-based study of RSV-related intermediate care and intensive care unit admissions in Switzerland over a 4-year period (2001-2005)

OBJECTIVES

Respiratory syncytial virus (RSV) infections are a leading cause of hospital admissions in small children. A substantial proportion of these patients require medical and nursing care, which can only be provided in intermediate (IMC) or intensive care units (ICU). This article reports on all children aged < 3 years who required admission to IMC and/or ICU between October 1, 2001 and September 30, 2005 in Switzerland.

PATIENTS AND METHODS

We prospectively collected data on all children aged < 3 years who were admitted to an IMC or ICU for an RSV-related illness. Using a detailed questionnaire, we collected information on risk factors, therapy requirements, length of stay in the IMC/ICU and hospital, and outcome.

RESULTS

Of the 577 cases reported during the study period, 90 were excluded because the patients did not fulfill the inclusion criteria; data were incomplete in another 25 cases (5%). Therefore, a total of 462 verified cases were eligible for analysis. At the time of hospital admission, only 31 patients (11%) were older than 12 months. Since RSV infection was not the main reason for IMC/ICU admission in 52% of these patients, we chose to exclude this subgroup from further analyses. Among the 431 infants aged < 12 months, the majority (77%) were former near term or full term (NT/FT) infants with a gestational age > or = 35 weeks without additional risk factors who were hospitalized at a median age of 1.5 months. Gestational age (GA) < 32 weeks, moderate to severe bronchopulmonary dysplasia (BPD), and congenital heart disease (CHD) were all associated with a significant risk increase for IMC/ICU admission (relative risk 14, 56, and 10, for GA < or = 32 weeks, BPD, and CHD, respectively). Compared with NT/FT infants, high-risk infants were hospitalized at an older age (except for infants with CHD), required more invasive and longer respiratory support, and had longer stays in the IMC/ICU and hospital.

CONCLUSIONS

In Switzerland, RSV infections lead to the IMC/ICU admission of approximately 1%-2% of each annual birth cohort. Although prematurity, BPD, and CHD are significant risk factors, non-pharmacological preventive strategies should not be restricted to these high-risk patients but also target young NT/FT infants since they constitute 77% of infants requiring IMC/ICU admission.

Chemokines and their receptors in respiratory disease: a therapeutic target for respiratory syncytial virus infection

Cell recruitment is a multistep process orchestrated by chemokines and their receptors. The chemokine/receptor system is central to many inflammatory diseases, making it a key target for therapeutic intervention. Despite complexity and redundancy within the system, effective antagonists are in development and undergoing clinical trials, for example, maraviroc, for use in HIV treatment. Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection in infants, with global annual infection estimated at 64 million people. Current treatment is purely supportive, with no effective vaccine available. RSV pathology is partly due to excessive airway inflammation. Evidence is growing for a key role for chemokine receptors. Receptor blockade may therefore provide a feasible therapeutic option to inhibit RSV-induced inflammation and thereby reduce disease severity.

Prospects of RNA interference therapy in respiratory viral diseases: update 2006

Respiratory viruses, such as influenza, parainfluenza and respiratory syncytial virus (RSV), claim millions of lives annually. At present, there is no completely effective vaccine or drug against these highly mutable RNA viruses. Passive antibody therapies for RSV, despite their limited application and staggering cost, enjoy a virtual monopoly in a multibillion-dollar global market. Recently, however, pioneering discoveries have launched RNA interference as a novel, nucleic acid-based therapy against viral pathogens. Specifically, small interfering RNAs (siRNAs) offered protection against respiratory syncytial virus, parainfluenza and influenza. siRNA against RSV has entered Phase I clinical trials in humans, and preliminary reports are promising. If appropriately formulated for improved specificity, delivery and pharmacokinetics, siRNAs may indeed become effective antivirals in the clinics of the future. This paper provides an overview of the prospects and hurdles facing the antiviral siRNA drugs, with special emphasis on RSV.