Epidemiological and economic burden of pneumococcal diseases in Canadian children

The epidemiology and healthcare costs of community-acquired pneumonia in Ontario, Canada: a population-based cohort study

OBJECTIVES

The aim of the present study was to determine incidence-based short- and long-term healthcare costs attributable to community-acquired pneumonia (CAP) from the healthcare payer perspective in Ontario, Canada.

METHODS

We conducted a retrospective population-based matched cohort study of residents in Ontario, Canada using health administrative data. We identified subjects with an incident episode of CAP (exposed subjects) between 1 January 2012 and 31 December 2014. The index date of each episode was based on the first inpatient or outpatient claim for pneumonia. Exposed subjects were matched without replacement to unexposed subjects from the general population using hard and propensity score matching on age, sex, income quintile, rural residence, comorbidities, and healthcare costs prior to index date. Attributable costs represented the mean difference in costs between the exposed subjects and their matched pairs.

RESULTS

We identified 692,090 subjects with at least one episode of CAP between 1 January 2012 and 31 December 2014. Adults aged 65 years and older had the highest annual incidence rate of 50.1 episodes per 1,000 person-years, while adults aged 18-64 years and children (aged 0-17) had incidence rates of 12.9 and 24.7 episodes per 1,000 person-years, respectively. The majority of episodes involved care exclusively in the outpatient setting (92.6%), with most of these episodes involving a single physician visit. The mean attributable costs were $1,595 (95% CI: $1,572-$1,616) per outpatient CAP episode and $12,576 (95% CI: $12.392-$12,761) per inpatient CAP episode. Attributable costs were significantly higher for adult subjects and those with time spent in the intensive care unit. Alternative case definitions yielded different results, although demonstrated the same overall trends across groups.

CONCLUSION

CAP is associated with substantially increased acute and long-term healthcare costs compared to unexposed subjects. This study highlights the burden of CAP in both the inpatient and outpatient setting, and will serve to inform strategic healthcare planning for future interventions and healthcare programs.

The cost of illness for childhood clinical pneumonia and invasive pneumococcal disease in Nigeria

BACKGROUND

Pneumococcal disease contributes significantly to childhood morbidity and mortality and treatment is costly. Nigeria recently introduced the pneumococcal conjugate vaccine (PCV) to prevent pneumococcal disease. The aim of this study is to estimate health provider and household costs for the treatment of pneumococcal disease in children aged <5 years (U5s), and to assess the impact of these costs on household income.

METHODS

We recruited U5s with clinical pneumonia, pneumococcal meningitis or pneumococcal septicaemia from a tertiary level hospital and a secondary level hospital in Kano, Nigeria. We obtained resource utilisation data from medical records to estimate costs of treatment to provider, and household expenses and income loss data from caregiver interviews to estimate costs of treatment to households. We defined catastrophic health expenditure (CHE) as household costs exceeding 25% of monthly household income and estimated the proportion of households that experienced it. We compared CHE across tertiles of household income (from the poorest to least poor).

RESULTS

Of 480 participants recruited, 244 had outpatient pneumonia, and 236 were hospitalised with pneumonia (117), septicaemia (66) and meningitis (53). Median (IQR) provider costs were US$17 (US$14-22) for outpatients and US$272 (US$271-360) for inpatients. Median household cost was US$51 (US$40-69). Overall, 33% of households experienced CHE, while 53% and 4% of the poorest and least poor households, experienced CHE, respectively. The odds of CHE increased with admission at the secondary hospital, a diagnosis of meningitis or septicaemia, higher provider costs and caregiver having a non-salaried job.

CONCLUSION

Provider costs are substantial, and households incur treatment expenses that considerably impact on their income and this is particularly so for the poorest households. Sustaining the PCV programme and ensuring high and equitable coverage to lower disease burden will reduce the economic burden of pneumococcal disease to the healthcare provider and households.

Retrospective Impact Analysis and Cost-Effectiveness of the Pneumococcal Conjugate Vaccine Infant Program in Australia

Australia introduced the 7-valent pneumococcal conjugate vaccine (7vPCV) on the universal infant National Immunisation Program (NIP) in 2005 and replaced it with the 13-valent pneumococcal conjugate vaccine (13vPCV) in 2011, both under a 3 + 0 schedule. The objective of this analysis was to quantify the clinical and economic impact of the universal infant PCV program in Australia from its introduction. A decision-analytic model was developed to estimate the historical impact of pneumococcal conjugate vaccine (PCV) programs in Australia from a direct health care perspective. Historical incidence of invasive pneumococcal disease (IPD), pneumonia, and otitis media (OM) were obtained from available Australian epidemiologic databases supplemented with published data. Costs were from Medicare Benefits Schedule in 2018 Australian dollars and utility weights from published sources. Historical observed changes in disease for the universal PCV NIP era (2005–2017) were compared against a “no-vaccine” scenario. The expected incidence for the no-vaccine scenario in years 2005–2017 was calculated using pre-universal PCV NIP era (2001–2004) data. Averted cases, deaths, incremental costs, and quality-adjusted life years (QALYs) were obtained by subtracting the vaccine scenario totals from the no-vaccine scenario totals. From the inclusion in the universal infant NIP, 7vPCV and 13vPCV are estimated to have prevented 1,770,024 cases of pneumococcal disease (IPD = 16,392; OM = 1,575,491; pneumonia = 102,059) and 1195 associated deaths. Over this period, there was a total 24,335 QALYs gained. Costs for the universal infant NIP were offset by $733 million direct costs saved, resulting in an incremental cost-effectiveness ratio of $3347 per QALY gained. PCVs have provided substantial public health and economic value from sustained use in Australia. Results are conservative, since long-term pneumococcal disease consequences and broader socioeconomic benefits were not considered. Maintaining 13vPCV on the Australian infant NIP under the newly implemented 2 + 1 schedule will likely provide more return on investment and sustained reductions in pneumococcal disease.

Effects of Delayed Antibiotic Therapy on Outcomes in Children with Streptococcus pneumoniae Sepsis

Delayed antimicrobial therapy is associated with poor outcomes in sepsis, but the optimal antibiotic administration time remains unclear. We aimed to investigate the effects of the time of antimicrobial administration on outcomes and evaluate an optimal empirical antibiotic administration time window for children with Streptococcus pneumoniae sepsis. This retrospective study enrolled children with S. pneumoniae sepsis who presented to the Children's Hospital of Chongqing Medical University from May 2011 to December 2018. Classification and regression tree (CART) analysis was used to determine the time-to-appropriate-therapy (TTAT) breakpoint. Outcomes were compared between patients receiving early or delayed therapy, defined by CART-derived TTAT breakpoint. During the study period, 172 patients were included. The CART-derived TTAT breakpoint was 13.6 h. After adjustment for confounding factors, a TTAT of ≥13.6 hours was found to be an independent predictor of sepsis-related in-hospital mortality (odds ratio [OR] = 39.26; 95% confidence interval [CI] = 6.10 to 252.60), septic shock (OR = 4.58; 95% CI = 1.89 to 11.14), and requiring mechanical ventilation (OR = 2.70; 95% CI = 1.01 to 7.35). A Pediatric Risk of Mortality (PRISM) III score of ≥10 was independently associated with delayed therapy. Delayed antibiotic therapy was associated with poor outcomes in children with S. pneumoniae sepsis. The optimal empirical antibiotic administration time window in children with S. pneumoniae sepsis was within 13.6 h. Efforts should be made to ensure timely and appropriate therapy.

Pneumococcal Vaccines: Host Interactions, Population Dynamics, and Design Principles

Streptococcus pneumoniae (the pneumococcus) is a nasopharyngeal commensal and respiratory pathogen. Most isolates express a capsule, the species-wide diversity of which has been immunologically classified into ∼100 serotypes. Capsule polysaccharides have been combined into multivalent vaccines widely used in adults, but the T cell independence of the antibody response means they are not protective in infants. Polysaccharide conjugate vaccines (PCVs) trigger a T cell–dependent response through attaching a carrier protein to capsular polysaccharides. The immune response stimulated by PCVs in infants inhibits carriage of vaccine serotypes (VTs), resulting in population-wide herd immunity. These were replaced in carriage by non-VTs. Nevertheless, PCVs drove reductions in infant pneumococcal disease, due to the lower mean invasiveness of the postvaccination bacterial population; age-varying serotype invasiveness resulted in a smaller reduction in adult disease. Alternative vaccines being tested in trials are designed to provide species-wide protection through stimulating innate and cellular immune responses, alongside antibodies to conserved antigens.

Clinical and Economic Impact of a Potential Switch from 13-Valent to 10-Valent Pneumococcal Conjugate Infant Vaccination in Canada

INTRODUCTION

Pneumococcal conjugate vaccines (PCVs) have been available in Canada since 2001, with 13-valent PCV (PCV13) added to the infant routine immunization program throughout all Canadian provinces by 2011. The use of PCVs has dramatically reduced the burden of pneumococcal disease in Canada. As a result, decision-makers may consider switching from a more costly, higher-valent vaccine to a lower-cost, lower-valent vaccine in an attempt to allocate funds for other vaccine programs. We assessed the health and economic impact of switching the infant vaccination program from PCV13 to 10-valent PCV (PCV10) in the context of the Canadian health care system.

METHODS

We performed a review of Canadian databases supplemented with published and unpublished data to obtain the historical incidence of pneumococcal disease and direct and indirect medical costs. Observed invasive pneumococcal disease (IPD) trends from surveillance data were used as a basis to forecast the future number of cases of IPD, pneumococcal pneumonia, and acute otitis media given a PCV13- or PCV10-based program. Costs and outcomes over 10 years were then estimated and presented in 2017 Canadian dollars discounted at 3% per year.

RESULTS

Switching from PCV13 to PCV10 would result in an additional 762,531 cases of pneumococcal disease over 10 years. Although PCV13 has a higher acquisition cost, switching to PCV10 would increase overall costs by over $500 million. Forecasted overall disease incidence was estimated substantially higher with PCV10 than with PCV13 primarily because of the potential reemergence of serotypes 3 and 19A. PCV13 was also cost saving compared with PCV10, even within a 5-year time horizon. Probabilistic sensitivity analysis showed that a PCV13-based program remained cost saving in all simulations.

CONCLUSION

Although switching to a PCV10-based infant vaccination program in Canada might result in lower acquisition costs, it would also result in higher public health cost and burden because of serotype reemergence.

FUNDING

Pfizer Inc.

Streptococcus pneumoniae serotype 1 burden in the African meningitis belt: exploration of functionality in specific antibodies

Streptococcus pneumoniae serotype 1 (Sp1) constitutes an important cause of seasonal endemic meningitis in all age groups in the African meningitis belt. Despite a higher meningitis incidence, the Burkinabé population has an Sp1-specific antibody seroprevalence similar to that reported in the United Kingdom (UK). We aimed to establish whether the opsonophagocytic activity (OPA) of pneumococcal IgG naturally present in Burkina Faso differs from that seen in individuals in the UK and to compare the OPAs generated by natural and vaccine-induced immunity. Samples collected from pneumococcal vaccine-naive Burkinabé and UK subjects were matched for age (1 to 39 years) and anti-Sp1 IgG level, analyzed for OPA to 3 S. pneumoniae serotypes (1, 5, and 19A), and compared to postvaccine samples. Furthermore, the Burkinabé samples were assessed for IgG avidity and serotype-specific IgM concentrations. One hundred sixty-nine matched serum samples from both populations were selected. A greater proportion of Burkinabé subjects aged 1 to 19 years had functional Sp1 activity (OPA ≥ 8) compared to UK subjects (12% versus 2%, P < 0.001); however, the proportions were similar among adults (9%). The correlation between Sp1 IgG concentration and OPA was good (P < 0.001), but many individuals had nonfunctional IgG, which was not related to avidity. While the Sp1 IgM concentrations correlated with OPA, not all of the function in serum samples with low IgG could be attributed to IgM. Finally, vaccine-induced Sp1-specific IgG was more functional than equivalent amounts of naturally occurring IgG. In conclusion, despite a substantially higher pneumococcal meningitis incidence, no decreased functional immunity to Sp1 could be evidenced in the Burkinabé population compared to that in the population from the UK. Furthermore, the naturally induced antibodies were less functional than vaccine-induced antibodies.

Antipneumococcal seroprevalence and pneumococcal carriage during a meningococcal epidemic in Burkina Faso, 2006

BACKGROUND

To better understand the high incidence of pneumococcal meningitis in the African meningitis belt, we conducted a pneumococcal seroprevalence study during a meningococcal meningitis epidemic in Western Burkina Faso, March 2006.

METHODS

In 3 villages experiencing epidemics, we included 624 healthy persons (1-39 years) by cluster sampling. We determined pneumococcal serum immunoglobulin G (IgG) antibody concentrations against 12 serotypes contained in 13-valent pneumococcal conjugate vaccine, and evaluated determinants for IgG ≥ 0.35 μg/mL by multivariate logistic regression.

RESULTS

The percentage of subjects with serotype-specific IgG concentrations ≥0.35 μg/mL increased with age and was similar for the different serotypes: it was 20%-43% among 1-4-year-olds and 56%-90% among 20-39-year-olds. Prevalence of IgG ≥ 0.35 μg/mL against serotype 1 was up to 71% after age 10 years. During multivariate analyses, determinants of IgG concentrations ≥0.35 μg/mL varied by serotype; for 5 and 6 serotypes, respectively, female sex (around 2-fold increased odds) and cigarette smoking (about 5-fold reduced odds) predicted elevated titers.

CONCLUSIONS

Despite a substantially higher historical pneumococcal meningitis incidence in Burkina Faso, the general population has an antibody seroprevalence against 12 pneumococcal serotypes similar to that reported from the United Kingdom. The role of putatively protective antibody seroprevalence in preventing pneumococcal meningitis in the meningitis belt requires more thorough evaluation.

Cost-effectiveness of 2 + 1 dosing of 13-valent and 10-valent pneumococcal conjugate vaccines in Canada

Background

Thirteen-valent pneumococcal conjugate vaccine (PCV13) and 10-valent pneumococcal conjugate vaccine (PCV10) are two recently approved vaccines for the active immunization against Streptococcus pneumoniae causing invasive pneumococcal disease in infants and children. PCV13 offers broader protection against Streptococcus pneumoniae; however, PCV10 offers potential protection against non-typeable Haemophilus influenza (NTHi). We examined public health and economic impacts of a PCV10 and PCV13 pediatric national immunization programs (NIPs) in Canada.

Methods

A decision-analytic model was developed to examine the costs and outcomes associated with PCV10 and PCV13 pediatric NIPs. The model followed individuals over the remainder of their lifetime. Recent disease incidence, serotype coverage, population data, percent vaccinated, costs, and utilities were obtained from the published literature. Direct and indirect effects were derived from 7-valent pneumococcal vaccine. Additional direct effect of 4% was attributed to PCV10 for moderate to severe acute otitis media to account for potential NTHi benefit. Annual number of disease cases and costs (2010 Canadian dollars) were presented.

Results

In Canada, PCV13 was estimated to prevent more cases of disease (49,340 when considering both direct and indirect effects and 7,466 when considering direct effects only) than PCV10. This translated to population gains of 258 to 13,828 more quality-adjusted life-years when vaccinating with PCV13 versus PCV10. Annual direct medical costs (including the cost of vaccination) were estimated to be reduced by $5.7 million to $132.8 million when vaccinating with PCV13. Thus, PCV13 dominated PCV10, and sensitivity analyses showed PCV13 to always be dominant or cost-effective versus PCV10.

Conclusions

Considering the epidemiology of pneumococcal disease in Canada, PCV13 is shown to be a cost-saving immunization program because it provides substantial public health and economic benefits relative to PCV10.

Health and economic impact of PHiD-CV in Canada and the UK: a Markov modelling exercise

OBJECTIVE

The spectrum of diseases caused by Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) represents a large burden on healthcare systems around the world. Meningitis, bacteraemia, community-acquired pneumonia (CAP), and acute otitis media (AOM) are vaccine-preventable infectious diseases that can have severe consequences. The health economic model presented here is intended to estimate the clinical and economic impact of vaccinating birth cohorts in Canada and the UK with the 10-valent, pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) compared with the newly licensed 13-valent pneumococcal conjugate vaccine (PCV-13).

METHODS

The model described herein is a Markov cohort model built to simulate the epidemiological burden of pneumococcal- and NTHi-related diseases within birth cohorts in the UK and Canada. Base-case assumptions include estimates of vaccine efficacy and NTHi infection rates that are based on published literature.

RESULTS

The model predicts that the two vaccines will provide a broadly similar impact on all-cause invasive disease and CAP under base-case assumptions. However, PHiD-CV is expected to provide a substantially greater reduction in AOM compared with PCV-13, offering additional savings of Canadian $9.0 million and £4.9 million in discounted direct medical costs in Canada and the UK, respectively.

LIMITATIONS

The main limitations of the study are the difficulties in modelling indirect vaccine effects (herd effect and serotype replacement), the absence of PHiD-CV- and PCV-13-specific efficacy data and a lack of comprehensive NTHi surveillance data. Additional limitations relate to the fact that the transmission dynamics of pneumococcal serotypes have not been modelled, nor has antibiotic resistance been accounted for in this paper.

CONCLUSION

This cost-effectiveness analysis suggests that, in Canada and the UK, PHiD-CV's potential to protect against NTHi infections could provide a greater impact on overall disease burden than the additional serotypes contained in PCV-13.

Cost-effectiveness of 13-valent pneumococcal conjugate vaccine: Germany, Greece, and The Netherlands

BACKGROUND

Seven-valent pneumococcal conjugate vaccine (PCV7) had profound public-health impacts and is considered cost-effective and potentially cost saving. Two new PCVs have been launched, a 10-valent vaccine (PCV10) and a 13-valent vaccine (PCV13). We examined public-health and economic impacts of PCV pediatric national immunization programs (NIPs) in Germany, Greece, and the Netherlands.

METHODS

A decision-analytic model was developed to estimate the impact of PCV13, PCV7, and 10-valent pneumococcal conjugate vaccine (PCV10) on invasive pneumococcal disease (IPD), pneumonia (PNE), and acute otitis media (AOM). Using epidemiological data, we calculated the cases of IPD, PNE, and AOM, using country-specific incidence, serotype coverage, disease sequelae, mortality, vaccine effectiveness, indirect effects, costs, and utilities. Direct effects for PCV13- and PCV10-covered serotypes were assumed similar to PCV7. PCV13 was assumed to confer an indirect effect, while PCV10 was not. Assumptions were tested in sensitivity analyses.

RESULTS

In a NIP, PCV13 was estimated to eliminate 31.7%, 46.4%, and 33.8% of IPD in Germany, Greece, and the Netherlands, respectively. Compared with PCV7 and PCV10, PCV13 was found to be cost-effective or cost saving in all cases when PCV13 indirect effects were included.

CONCLUSIONS

Pediatric NIPs with PCV13 in Europe are expected to have dramatic public-health impacts and be cost-effective or cost saving.

Update on acute otitis media in children younger than 2 years of age

QUESTION

As concern about antimicrobial resistance grows, I am aware of the need to reduce unnecessary antibiotic treatment; however, in my practice I see many children with acute otitis media (AOM) and this is the most common reason I prescribe antibiotics. Most of these children are young and otherwise healthy, and I am uncertain about when to prescribe antibiotics and when to endorse "watchful waiting." Which children will benefit from antibiotic treatment?

ANSWER

Current Canadian guidelines recommend all children younger than 2 years of age with otalgia due to AOM and fever greater than 39°C be considered for treatment with amoxicillin. Watchful waiting is indicated only for children older than 6 months with mild-to-moderate AOM. Recent evidence suggests young children with a definitive diagnosis of AOM will benefit from antibiotics and experience fewer treatment failures compared with placebo, regardless of the severity of otitis. These studies do not challenge watchful waiting directly, and determining which children will improve spontaneously remains an enigma.

Pneumococcal conjugate vaccination in Canadian infants and children younger than five years of age: Recommendations and expected benefits

INTRODUCTION

Streptococcus pneumoniae infection may result in invasive pneumococcal disease (IPD), such as bacteremia, meningitis and bacteremic pneumonia, or in non-IPD, such as pneumonia, sinusitis and otitis media. In June 2001, a heptavalent pneumococcal conjugate vaccine (PCV7) (Prevnar, Wyeth Pharmaceuticals, Canada) was approved for use in children in Canada. The objective of the present paper is to review S pneumoniae-induced disease incidence and vaccine recommendations in Canadian infants and children younger than five years of age. Particular attention is given to the expected benefits of vaccination in Canada based on postmarketing data and economic modelling.

METHODS

Searches were performed on PubMed and Web of Science databases and specific Canadian journals using the key words 'pneumococc*', 'vaccine', 'conjugate', 'infant' and 'Canadian'.

RESULTS AND DISCUSSION

PCV7 appears to be safe and effective against IPD and non-IPD in children younger than five years of age and, more importantly, in children younger than two years of age (who are at highest risk for IPD). An examination of postmarketing data showed a reduction in incidence of pneumococcal disease in age groups that were vaccinated and in older age groups, indicating the likelihood of herd protection. Concurrently, there was a reduction in the occurrence of antimicrobial-resistant isolates.

CONCLUSIONS

The results from the present review suggest that PCV7 is currently benefiting Canadian children and society by lowering S pneumoniae-associated disease. Additional gains from herd protection and further reductions in antimicrobial resistance will be achieved as more Canadian children younger than five years of age are routinely vaccinated with PCV7.

The burden of pneumococcal disease in children less than 5 years of age in Abu Dhabi, United Arab Emirates

BACKGROUND AND OBJECTIVE

Streptococcus pneumoniae is a major cause of mortality and morbidity in both developing and industrialized countries, especially among young children and in both immunocompromised and immunocompetent individuals. It is implicated in both invasive (e.g. meningitis and septicemia) as well as noninvasive disease (community-acquired pneumonia and otitis media). The objective of the current study was to describe the overall epidemiology of both invasive and noninvasive pneumococcal disease in Abu Dhabi over a 5-year period.

DESIGN AND SETTING

Retrospective review of all pediatric (≤ 5 year old) pneumococcal disease admissions to Shaikh Khalifa Medical City (SKMC) and Mafraq Hospital in Abu Dhabi from 1 January 2001 till 31 December 2005.th

METHODS

We retrieved computerized data from the health information management systems (International Classification of Diseases, 9th Revision (ICD9) diagnosis codes) as well as manual surveillance in the laboratory record of pneumococcal isolates.

RESULTS

The incidence of invasive pneumococcal disease was 13.6/100, 000 per year (95% CI, 6.5-24.9) and the incidence of noninvasive pneumococcal disease was 172.5/100,000 per year (95% CI, 143.8-205.2). The total incidence rate was 186.0/100, 000 per year (95% CI, 156.2-219.9).

CONCLUSION

This epidemiological survey indicates that the incidence rates in the United Arab Emirate are higher than in Western countries where conjugate pneumococcal vaccine has been introduced. This study is important as it documents the incidence of pneumococcal disease in the era before introduction of the conjugate pneumococcal vaccine and allows for future research to document the impact of a new vaccine considering the geographic variation of pneumococcal serotypes.

Cost effectiveness of pneumococcal conjugate vaccination against acute otitis media in children: a review

While pneumococcal conjugate vaccines have shown to be highly effective against invasive pneumococcal disease, their potential effectiveness against acute otitis media (AOM) might become a major economic driver for implementing these vaccines in national immunization programmes. However, the relationship between the costs and benefits of available vaccines remains a controversial topic. Our objective is to systematically review the literature on the cost effectiveness of pneumococcal conjugate vaccination against AOM in children. We searched PubMed, Cochrane and the Centre for Reviews and Dissemination databases (Database of Abstracts of Reviews of Effects [DARE], NHS Economic Evaluation Database [NHS EED] and Health Technology Assessment database [HTA]) from inception until 18 February 2010. We used the following keywords with their synonyms: 'otitis media', 'children', 'cost-effectiveness', 'costs' and 'vaccine'. Costs per AOM episode averted were calculated based on the information in this literature. A total of 21 studies evaluating the cost effectiveness of pneumococcal conjugate vaccines were included. The quality of the included studies was moderate to good. The cost per AOM episode averted varied from &U20AC;168 to &U20AC;4214, and assumed incidence rates varied from 20,952 to 118,000 per 100,000 children aged 0-10 years. Assumptions regarding direct and indirect costs varied between studies. The assumed vaccine efficacy of the 7-valent pneumococcal CRM197-conjugate vaccine was mainly adopted from two trials, which reported 6-8% efficacy. However, some studies assumed additional effects such as herd immunity or only took into account AOM episodes caused by serotypes included in the vaccine, which resulted in efficacy rates varying from 12% to 57%. Costs per AOM episode averted were inversely related to the assumed incidence rates of AOM and to the estimated costs per AOM episode. The median costs per AOM episode averted tended to be lower in industry-sponsored studies. Key assumptions regarding the incidence and costs of AOM episodes have major implications for the estimated cost effectiveness of pneumococcal conjugate vaccination against AOM. Uniform methods for estimating direct and indirect costs of AOM should be agreed upon to reliably compare the cost effectiveness of available and future pneumococcal vaccines against AOM.

Burden of acute otitis media on Canadian families

OBJECTIVE

To estimate the burden of acute otitis media (AOM) on Canadian families.

DESIGN

Telephone survey using random-digit dialing.

SETTING

All Canadian provinces between May and June 2008.

PARTICIPANTS

Caregivers of 1 or more children aged 6 months to 5 years.

MAIN OUTCOME MEASURES

Caregivers' reports on the number of AOM episodes experienced by the child in the past 12 months, as well as disease characteristics, health services and medication use, time spent on medical consultations (including travel), and time taken off from work to care for the sick children.

RESULTS

A total of 502 eligible caregivers were recruited, 161 (32%) of whom reported at least 1 AOM episode for their children and 42 (8%) of whom reported 3 or more episodes during the past 12 months. Most children (94%, 151 of 161) visited with health professionals during their most recent AOM episodes. The average time required for medical examination was 3.1 hours in an emergency department and 1.8 hours in an outpatient clinic. Overall, 93% of episodes resulted in antibiotics use. A substantial proportion of caregivers (38%) missed work during this time; the average time taken off work was 15.9 hours.

CONCLUSION

In Canada, episodes of AOM are still associated with substantial use of health services and indirect costs to the caregivers.

Burden and cost of hospital admissions for vaccine-preventable paediatric pneumococcal disease and non-typable Haemophilus influenzae otitis media in New Zealand

INTRODUCTION

Streptococcus pneumoniae (Sp.) is a leading cause of paediatric bacterial meningitis, pneumonia and acute otitis media, as is non-typable Haemophilus influenzae (NTHi) for acute otitis media. In 2008, a 7-valent conjugated pneumococcal vaccine (PCV7) was included in the New Zealand (NZ) childhood immunization schedule.

OBJECTIVE

To estimate the potentially vaccine-preventable annual hospital admissions and cost to the NZ Government of paediatric admissions for pneumococcal disease and NTHi otitis media prior to the immunization programme.

METHODS

Admissions (2000-7) and deaths (2000-5) in children aged<20 years with pneumococcal meningitis or bacteraemia, pneumonia or otitis media were identified in national datasets and linked by unique patient identifiers. New episodes of illness were defined as admissions occurring >30 days after discharge from a previous admission. Informed by the literature, pneumococcal pneumonia episodes were estimated at 33% of all-cause pneumonia admissions; Sp. and NTHi otitis media episodes were estimated jointly at 72% of otitis media admissions. Each episode was assigned a single diagnosis according to the following hierarchy: meningitis>bacteraemia>pneumonia>otitis media. Incidence rates for episodes were determined for 2000-7 (meningitis, bacteraemia and pneumonia) and 2006-7 (otitis media). Annual DRG-based costs for pneumococcal meningitis, bacteraemia, pneumonia and otitis media were estimated as (episode rate)x(DRG cost weight per episode)x(2007 population)x(national price per cost weight).

RESULTS

Episode rates for pneumococcal meningitis, bacteraemia and pneumonia were stable in 2000-7, highest in the second 6 months of life and declined steeply over the first 5 years of life. Mean rates per 100000 in 2000-7 were 18.4, 27.6 and 464 for pneumococcal meningitis, bacteraemia and pneumonia, respectively, for children aged<2 years; 8.4, 14.9 and 295 for children aged<5 years (including those aged<2 years); and 2.2, 4.4 and 97 for children aged<20 years (including those aged<5 years). Mean rates per 100000 in 2006-7 for Sp. and NTHi otitis media combined were 631 (surgical) and 197 (medical) for children aged<2 years; 691 and 116 for children aged<5 years; and 281 and 35 for children aged<20 years. Pacific Island and indigenous Māori children generally had higher rates than European/other children. Rates increased with socioeconomic disadvantage, across all diagnoses. The annual cost to Government of pneumococcal disease and NTHi otitis media admissions for children aged<20 years was estimated at New Zealand dollars ($NZ)9.95 million (range 7.7-12.2 million) [about $US7.1 million]. Most of this cost was shared between pneumococcal pneumonia (48%) and otitis media (45%), and 78% was incurred in the first 2 years of life. Estimated annual paediatric mortality rates per 100 000 for children aged<5 years were 0.48, 0.30 and 0.54 for pneumococcal meningitis, bacteraemia and pneumonia, respectively. The analysis predicted four or five pneumococcal deaths per year (range 1-8) for children aged<5 years.

CONCLUSIONS

Prior to the introduction of a national Sp. immunization programme, hospital admissions for Sp. disease and NTHi otitis media in NZ cost about $NZ10 million annually, mostly for children aged<2 years and particularly for those living in relative socioeconomic deprivation and for Pacific Island and Māori children. There were about five pneumococcal deaths annually. With adjustment for local serotypes, vaccine serotype coverage and uptake, immunization with any of the three available pneumococcal vaccines would reduce this burden substantially.

Health related quality of life in survivors of pneumococcal meningitis

AIM

To estimate the overall long-term health related quality of life implications of an episode of pneumococcal meningitis in childhood.

METHOD

Cases were identified through two regional UK surveillance studies and traced via their general practitioners (GPs) or local hospital paediatrician. Siblings were used as controls where available. Health related quality of life was assessed using the health utilities index (HUI). Mean utility scores were compared between cases and controls and univariate linear regression was used to identify factors that influenced the overall utility scores.

RESULTS

HUI data were available for 71 cases and 66 controls. The mean overall utility score for cases 0.774 (95% CI 0.711- 0.837) was significantly lower than for controls 0.866 (95% CI 0.824-0.907) (p-value = 0.0185). Hearing was the most significantly affected health attribute (p-value < 0.006). In cases, males had lower quality of life scores than females (p-value = 0.018), however this was not seen in controls.

CONCLUSION

An episode of pneumococcal meningitis results in a long-term decrement in overall health related quality of life and is significantly related to hearing loss.

The burden of pneumococcal disease in the Canadian population before routine use of the seven-valent pneumococcal conjugate vaccine

BACKGROUND

In the United States, implementation of the seven-valent conjugate vaccine into childhood immunization schedules has had an effect on the burden of pneumococcal disease in all ages of the population. To evaluate the impact in Canada, it is essential to have an estimate of the burden of pneumococcal disease before routine use of the vaccine.

METHODS

The incidence and costs of pneumococcal disease in the Canadian population in 2001 were estimated from various sources, including published studies, provincial databases and expert opinion.

RESULTS

In 2001, there were 565,000 cases of pneumococcal disease in the Canadian population, with invasive infections representing 0.7%, pneumonia 7.5% and acute otitis media 91.8% of cases. There were a total of 3000 deaths, mainly as a result of pneumonia and largely attributable to the population aged 65 years or older. There were 54,330 life-years lost due to pneumococcal disease, and 37,430 quality-adjusted life-years lost due to acute disease, long-term sequelae and deaths. Societal costs were estimated to be $193 million (range $155 to $295 million), with 82% borne by the health system and 18% borne by families. Invasive pneumococcal infections represented 17% of the costs and noninvasive infections represented 83%, with approximately one-half of this proportion attributable to acute otitis media and myringotomy.

CONCLUSIONS

The burden of pneumococcal disease before routine use of the pneumococcal conjugate vaccine was substantial in all age groups of the Canadian population. This estimate provides a baseline for further analysis of the direct and indirect impacts of the vaccine.

Convincing or confusing? Economic evaluations of childhood pneumococcal conjugate vaccination--a review (2002-2006)

We review 15 economic analyses of pneumococcal conjugate vaccines, published between 2002 and 2006, in terms of methodology, assumptions, results and conclusions. We found a great diversity in assumptions (eg, vaccine efficacy parameters, incidence rates for both invasive and non-invasive disease) mainly due to local variation in data and opinions. Accordingly, the results varied greatly, from total net savings to over euro 100,000 per discounted QALY gained. The cost of the vaccination program (determined by price per dose and schedule (4 or 3 doses, or fewer)), and likely herd immunity impacts are highly influential though rarely explored in these published studies. If the net long-term impact (determined by a mixture of effects related to herd immunity, serotype replacement, antibiotic resistance and cross reactivity) remains beneficial and if a 3-dose schedule confers near-equivalent protection to a 4-dose schedule, the cost-effectiveness of PCV7 vaccination programs can be viewed as attractive in developed countries.

An analytical framework for immunization programs in Canada

Recent years have seen an increase in the number of new vaccines available on the Canadian market, and increasing divergence in provincial and territorial immunization programs as jurisdictions must choose among available health interventions with limited funding. We present an analytical framework, which we have developed to assist in the analysis and comparison of potential immunization programs. The framework includes 58 criteria classified into 13 categories, including the burden of disease, vaccine characteristics and immunization strategy, cost-effectiveness, acceptability, feasibility, and evaluability of program, research questions, equity, ethical, legal and political considerations. To date this framework has been utilized in a variety of different contexts, such as to structure expert presentations and reports and to examine the degree of consensus and divergence among experts, and to establish priorities. It can be transformed for a variety of other uses such as educating health professionals and the general public about immunization.

Potential conflicts of interest in vaccine economics research: a commentary with a case study of pneumococcal conjugate vaccination

The main potential areas of bias in economic evaluation (EE) in health care can be categorised as follows: (1) choosing the study question and design, (2) estimating clinical effectiveness; (3) choosing cost data sources, and (4) reporting and dissemination of results. Each of these is discussed while focusing on vaccines. In addition a case study is presented on two contemporary economic evaluations of pneumococcal conjugate vaccination for Canada. Though they are quite similar in design and methods, their results are not quite so. This paper explores the differences between them in relation to the four areas of bias. Finally, remedies to avoid bias in research and publications are proposed and discussed.