Cost-benefit analysis for the use of Haemophilus influenzae type b conjugate vaccine in Santiago, Chile

Efficacy and Prolonged Safety of Haemophilus influenzae Type b Conjugate Vaccines

OBJECTIVE

The purpose of this study was to find data proving the influence of the Haemophilus influenzae type b (Hib) conjugate vaccination on the frequency of invasive Hib illness.

METHODOLOGY

A systematic literature search was conducted on the PubMed database to identify peerreviewed publications pertaining to the epidemiology of Haemophilus influenzae meningitis, both before and after the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines. The search query employed a combination of relevant keywords, including "invasive," "Haemophilus," "influenzae," "meningitis," and specific serotype b (Hib). Additionally, terms related to epidemiology, burden, risk factors, impact, Hib vaccine, Hib conjugate vaccine, combination vaccine, vaccine production, efficacy, immunisation coverage, surveillance, review, clinical aspects, outcomes, and various age groups (adults and children) were incorporated.

RESULT

The search encompassed articles published till now. Subsequently, relevant research papers concerning Haemophilus influenzae meningitis were subjected to a comprehensive review and analysis.

CONCLUSION

The Hib conjugate vaccination has shown to be extremely effective when administered to the entire population. However, changes to the immunisation protocol appear to be required in order to effectively manage invasive Hib illness.

Estimating costs of care for meningitis infections in low- and middle-income countries

Meningitis infections are often associated with high mortality and risk of sequelae. The costs of treatment and care for meningitis are a great burden on health care systems, particularly in resource-limited settings. The objective of this study is to review data on the costs of care for meningitis in low- and middle-income countries, as well as to show how results could be extrapolated to countries without sound data. We conducted a systematic review of the literature from six databases to identify studies examining the cost of care in low- and middle-income countries for all age groups with suspected, probable, or confirmed meningitis. We extracted data on treatment costs and sequelae by infectious agent and/or pathogen, where possible. Using multiple regression analysis, a relationship between hospital costs and associated determinants was investigated in order to predict costs in countries with missing data. This relationship was used to predict treatment costs for all 144 low- and middle-income countries. The methodology of conducting a systematic review, extrapolating, and setting up a standard database can be used as a tool to inform cost-effectiveness analyses in situations where cost of care data are poor. Both acute and long-term costs of meningitis could be extrapolated to countries without reliable data. Although only bacterial causes of meningitis can be vaccine-preventable, a better understanding of the treatment costs for meningitis is crucial for low- and middle-income countries to assess the cost-effectiveness of proposed interventions in their country. This cost information will be important as inputs in future cost-effectiveness studies, particularly for vaccines.

Progress in vaccination against Haemophilus influenzae type b in the Americas

The authors review the progress to date in Hib vaccine introduction, the lessons learned, and the remaining challenges.

The cost of treatment for child pneumonias and meningitis in the Northern Areas of Pakistan

Pneumonia, meningitis, and sepsis place a significant economic burden on health care systems, particularly in developing countries. This study estimates treatment costs for these diseases in health facilities in the Northern Areas of Pakistan. Health facility resources are organized by categories--including salaries, capital costs, utilities, overhead, maintenance and supplies--and quantified using activity-based costing (ABC) techniques. The average cost of treatment for an outpatient case of child pneumonia is dollar 13.44. For hospitalized care, the health system spent an average of dollar 71 per episode for pneumonia, dollar 235 for severe pneumonia, and dollar 2,043 for meningitis. These costs provide important background information for the potential introduction of the conjugate Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae vaccines in Pakistan.

Efficacy of Haemophilus influenzae type b vaccination of children: a meta-analysis

Haemophilus influenzae type b (Hib) infection is a leading cause of meningitis and pneumonia in infants and children in developing countries, and yet the implementation of routine Hib vaccination is very slow. The aim of the present study was to quantify the protective efficacy of H. influenzae type b vaccination of young children. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials Register were searched. References of selected articles were also reviewed and experts contacted. Eight randomized trials were found that compared the efficacy of H. influenzae type b conjugate vaccine to placebo or no vaccine. Information on study design, patients enrolled, age, vaccine type, cases of invasive H. influenzae type b disease, adverse events, and items to assess potential for bias was recorded. The incidence of invasive H. influenzae type b infection formed the primary outcome. The odds ratio (OR) of developing Hib infection was combined using a random effects model to provide a measure of vaccine efficacy. The protective effect, defined as the relative risk reduction, was estimated as (1-OR). From eight trials, the protective efficacy of the Hib conjugate vaccine was 84% (OR 0.16; 95%CI 0.08-0.30) against invasive Hib disease, 75% (OR 0.25; 95%CI 0.08-0.84) against meningitis, and 69% (OR 0.31; 95%CI 0.10-0.97) against pneumonia. Serious adverse events were rare. The results provide firm evidence that Hib conjugate vaccines are safe and effective in reducing the risk of all forms of invasive Hib disease, further establishing that vaccination of children in developing countries can protect them from a potentially fatal yet preventable disease.

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.

Economic evaluation of Haemophilus influenzae type b vaccination in Moscow, Russian Federation

OBJECTIVE

To estimate the cost-effectiveness of providing Haemophilus influenzae type b (Hib) vaccine to children in Moscow in routine immunization services.

METHODS

The incidence of Hib meningitis among children aged <5 years in Moscow was obtained from a prospective surveillance study undertaken during October 1999-September 2001, with treatment cost data collected for all cases. Sequelae in surviving children were assessed in December 2002. The costs of Hib vaccination in Moscow were estimated assuming a vaccine price of US dollar 5 per dose and the same four-dose schedule and 97% coverage as for diphtheria-tetanus-pertussis vaccine. The most uncertain variables were varied in a sensitivity analysis.

RESULTS

The annual incidence of Hib meningitis was 5.7 per 100,000 children <5 years. The average treatment cost for an acute Hib meningitis case was US dollar 1296. For a patient with sequelae, the average additional lifetime discounted treatment cost was US dollar 15,820. The total annual cost of Hib vaccination of infants in Moscow was estimated as US dollar 1.5 million per year. In the base case analysis, the cost-effectiveness ratios amount to US dollar 77,503 per Hib meningitis case averted and US dollar 10,842 per discounted disability adjusted life year averted. The break-even vaccine price, where the annual vaccination costs equal annual treatment costs averted, is only US dollar 0.04 per dose in the base case scenario. If discounted indirect costs are included, the break-even vaccine price is US dollar 0.5 per dose.

CONCLUSION

In Moscow, the incidence of Hib meningitis is low and the costs of hospitalization and subsequent medical treatment are relatively inexpensive. Given these factors, Hib vaccine at US dollar 5 per dose would not be a cost-effective option in Moscow at the present time.

Cost-effectiveness of universal childhood hepatitis A vaccination in Chile

Hepatitis A is an important public health problem in Chile. Childhood vaccination has reduced hepatitis A rates in several countries, prompting this evaluation of its cost-effectiveness in Chile. Using a Markov model, we project mass vaccination would reduce hepatitis A cases among birth cohort members and their personal contacts >80%. Vaccination costs of US dollars 5.3-6.4 million would be offset by US dollars 9.2-9.4 million reductions in disease costs. Further, approximately 70 fatal infections would be averted and >4600 quality-adjusted life years would be saved. This analysis supports the cost-effectiveness of universal childhood hepatitis A vaccination in Chile.

ARE VACCINATION SITES IN BANGLADESH SCALE EFFICIENT?

Objectives: The overall aim of this study is to discern whether and to what degree vaccination sites exhibit constant returns to scale.

Methods: Data Envelopment Analysis is used to compare all the facilities in the sample in terms of input costs used to produce multiple outputs. The application considers the Expanded Program on Immunization (EPI), which operated in Dhaka City, Bangladesh, during 1999.

Results: A preponderance of EPI sites were determined to be operating at increasing returns to scale.

Conclusions: Our findings question the applicability of cost-effectiveness analyses that assume constant returns to scale.

Are economic evaluations of vaccines useful to decision-makers? Case study of Haemophilus influenzae type b vaccines

BACKGROUND

In concert with efforts to increase global provision, economic evaluations of newer and relatively costly vaccines have proliferated in the medical literature. The extent to which existing vaccine evaluations are useful to decision makers is not clear. We conducted a systematic review of published economic evaluations of conjugate Haemophilus influenzae type b (Hib) vaccine, anticipating that their usefulness to past and present decision makers would be limited by the quality of the analyses and by the extent to which the results were transferable to other settings.

METHODS

We systematically identified economic evaluations of conjugate Hib vaccine. We appraised their quality according to a customized checklist and assessed the extent of and reasons for variability of the results.

RESULTS

Quality assessment of the available economic evaluations disclosed a number of shortcomings, including the failure across all models to derive systematic estimates of vaccine efficacy as well as a lack of transparency in the costing of Hib disease treatment. Wide variations in results appeared to be caused primarily by epidemiologic and health system differences between settings and secondarily to methodologic differences between models. The generalizability of model results appeared low.

CONCLUSIONS

There is scope for improving the overall quality of economic evaluations of Hib vaccination. Relevance to decision makers may also be increased by addressing local budget constraints and vaccine price. There is a need to better understand the decision process, particularly at the national level, to ensure the role of future economic evaluations as important decision tools in the implementation of new vaccines.

Population-based surveillance for hospitalized and ambulatory pediatric invasive pneumococcal disease in Santiago, Chile

BACKGROUND

Nine- and 11-valent pneumococcal conjugate vaccines under development may control pediatric pneumococcal disease in nonindustrialized countries. Because these vaccines are expensive, population-based surveillance of pneumococcal disease in children <36 months of age was undertaken in Santiago, Chile to provide health authorities with reliable data on the burden of invasive pneumococcal disease and causative serotypes, including those in outpatients with high fever.

METHODS

Automated blood culture machines were introduced into 9 hospitals that admit 85% of all hospitalized children in Santiago. Acutely ill pediatric febrile ambulatory patients are attended at 8 emergency rooms (ERs) and 36 urgent primary care services. After a 12-month pilot study in 3 ERs, health authorities collected blood cultures from children <36 months of age with high fever seen in the ER as standard practice. isolates were serotyped.

RESULTS

Blood cultures of 18 (1.2%) of 1,503 outpatients 6 to 35 months of age with high fever in the pilot study yielded S. In the ensuing 24 months 236 children <36 months old were hospitalized with invasive pneumococcal disease (incidence, 33.9 cases/10(5) children), and 188 bacteremias were detected among ambulatory ER patients with high fever (incidence, 27.0 cases/10(5) children). Although serotypes were similar among hospitalized and ambulatory cases (except 18C, which was more common in the latter), case fatality was 9.5% in hospitalized (21 of 236) 0% in ambulatory cases (0 of 188) (P = <0.0001). High level resistance to penicillin (25.8% vs 10.1%) and cefotaxime (19.5% vs 6.2%) was observed more often among pneumococcal isolates from hospitalized than among ambulatory cases (P < 0.001).

CONCLUSIONS

ER surveillance detected approximately one case of pneumococcal bacteremia among febrile ambulatory patients for each hospitalized invasive case. Because 71% of cases were caused by vaccine serotypes (and 87% by vaccine serogroups), 9- and 11-valent pneumococcal conjugate vaccines could prevent most invasive pediatric pneumococcal disease in Chile.

Impact of universal Haemophilus influenzae type b vaccination starting at 2 months of age in the United States: an economic analysis

OBJECTIVE

To evaluate the economic impact of universal Haemophilus influenzae type b (Hib) vaccination starting at 2 months of age.

METHODS

Decision-tree-based analysis was conducted of a hypothetical US birth cohort of 3 815 469 infants using population-based vaccination coverage and disease incidence data. All costs were estimated from both the direct cost (medical and nonmedical) and societal perspectives. Net present value, cost-effectiveness ratios, and benefit-cost ratios of the US Hib vaccination program were evaluated.

RESULTS

The results of these analyses showed that the universal vaccination program using the Hib conjugate vaccines in the United States in 2000 was cost-saving from both the direct and societal perspectives, with the benefit of the Hib vaccination program (net present value) from the direct cost and societal perspectives of $0.95 billion and $2.09 billion, respectively. Without a Hib vaccination program, the direct and societal costs of Hib invasive cases would be $1.35 billion and $2.58 billion, respectively. The direct and societal costs of the Hib vaccination program were estimated at $0.39 billion and $0.48 billion, respectively. The direct and societal benefit-cost ratios for the Hib vaccination program were 3.4 and 5.4, respectively. Varying the proportion of vaccines purchased and administered in the public versus the private sector and the proportion of combination vaccine versus monovalent vaccine administered did not have much effect on the results.

CONCLUSIONS

Regardless of the perspective (direct cost or societal) and the assumptions used, the benefit-cost ratios of the US vaccination program are >1.0. Potential changes in the program, including use of more or less Hib combination vaccines, would not significantly alter the benefit-cost ratio. The national Hib vaccination program is highly cost beneficial and results in substantial cost savings.

Economic evaluation of Haemophilus influenzae type b vaccination in Slovenia

The objective of the present study was to assess the economical impact of invasive Haemophilus influenzae type b infections in Slovenia, where the annual incidence of these infections is 16.4/100000 in children less than 5 years of age, and to compare it with the costs of a vaccination programme. The lifetime costs and benefits were estimated for the annual birth cohort of 18200 children. In the base-case model, the calculated benefit-to-cost ratios were 0.15, 0.98 and 1.38 taking into account 95% of savings in acute care costs, medical costs, and medical and non-medical costs, respectively. From the point of view of the Institute of Health Insurance of Slovenia, who pays all healthcare and vaccination costs, the vaccination programme per annual birth cohort of 18200 children would require an extra 7023 EUR or 0.40 EUR per cohort-child. The savings to society would represent 118410 EUR, indicating the rationale for inclusion of H. influenzae type b vaccination in the routine childhood immunisation programme in Slovenia.

Cost-benefit analysis of a Haemophilus influenzae type b meningitis prevention programme in The Philippines

BACKGROUND

Haemophilus influenzae type b (Hib) meningitis is associated with high mortality and serious sequelae in children under 5 years of age. Vaccines which can prevent this infection are available.

OBJECTIVE

To evaluate the costs and benefits of a 3-dose immunisation schedule in Manila, Philippines.

PERSPECTIVE

Government and societal perspectives.

DESIGN AND PARTICIPANTS

A cost-benefit analysis based on a birth cohort of 100,000 children. The state of health of the cohort with and without a Hib immunisation programme was modelled over a 5-year period. A survey of medical records of patients with Hib in Manila provided data on the extent and cost of sequelae following infection.

INTERVENTION

A 3-dose Hib vaccination programme given at ages 2, 3 and 4 months.

RESULTS

The model predicted that vaccinating children against Hib meningitis would prevent 553 cases per year in a birth cohort of 100,000, at a cost of 56,200 Philippine pesos (PHP) [$US1,605; 1998 exchange rate] per case (base case assumptions of 90% vaccine efficacy rate, 95 per 100,000 Hib incidence rate, 85% vaccination coverage). Results from the cost-benefit analyses indicated that the saving to the government would be around PHP39 million ($US1.11 million), and the saving to society would be PHP255 million ($US7.28 million).

CONCLUSION

There would be a positive economic benefit for the Philippine government and for the Filipino society if a Hib vaccination programme was introduced in Manila.

Worldwide Haemophilus influenzae type b disease at the beginning of the 21st century: global analysis of the disease burden 25 years after the use of the polysaccharide vaccine and a decade after the advent of conjugates

Vaccination against Haemophilus influenzae type b (Hib) diseases began a quarter of a century ago with a polysaccharide vaccine; this vaccine was followed by four different conjugates 10 years later. In this review, the burden of global Hib disease is quantified following this 25-year period of vaccine availability to determine the potential impact of conjugate vaccines. This task was accomplished by analysis of data available in 10 languages in 75 geographical regions of over 50 countries. All severe Hib diseases, not only meningitis, were characterized, and special attention was paid to the most vulnerable age group, i.e., children aged 0 to 4 years. Prior to vaccination, the weighted worldwide incidence of meningitis in patients younger than 5 years was 57/100,000, and for all Hib diseases except nonbacteremic pneumonia, it was 71/100,000, indicating 357,000 and 445,000 cases per year, respectively. At least 108,500 of these children died. For all age groups combined, there were 486,000 cases of Hib disease, excluding pneumonia, with 114,200 deaths and probably an equal number of sequelae per annum. If the figures for nonbacteremic pneumonia are included, a conservative estimate is that over 2.2 million cases of infection and 520,000 deaths from Hib disease occurred worldwide, but the true numbers might have been greater. Despite these large numbers and availability of safe and efficacious vaccines, only 38,000 cases annually are prevented-a meager 8% or less than a 2% reduction in cases, depending on whether nonbacteremic pneumonia is included in the calculations. Although vaccination has had great success in some affluent countries, the current level of activity has had a very small impact globally. The use of conjugates, preferably with a reduced number of doses and in combination with other vaccines or perhaps in fractional doses, should be extended to less privileged countries, where most Hib disease occurs.

Worldwide Haemophilus influenzae type b disease at the beginning of the 21st century: global analysis of the disease burden 25 years after the use of the polysaccharide vaccine and a decade after the advent of conjugates

Vaccination against Haemophilus influenzae type b (Hib) diseases began a quarter of a century ago with a polysaccharide vaccine; this vaccine was followed by four different conjugates 10 years later. In this review, the burden of global Hib disease is quantified following this 25-year period of vaccine availability to determine the potential impact of conjugate vaccines. This task was accomplished by analysis of data available in 10 languages in 75 geographical regions of over 50 countries. All severe Hib diseases, not only meningitis, were characterized, and special attention was paid to the most vulnerable age group, i.e., children aged 0 to 4 years. Prior to vaccination, the weighted worldwide incidence of meningitis in patients younger than 5 years was 57/100,000, and for all Hib diseases except nonbacteremic pneumonia, it was 71/100,000, indicating 357,000 and 445,000 cases per year, respectively. At least 108,500 of these children died. For all age groups combined, there were 486,000 cases of Hib disease, excluding pneumonia, with 114,200 deaths and probably an equal number of sequelae per annum. If the figures for nonbacteremic pneumonia are included, a conservative estimate is that over 2.2 million cases of infection and 520,000 deaths from Hib disease occurred worldwide, but the true numbers might have been greater. Despite these large numbers and availability of safe and efficacious vaccines, only 38,000 cases annually are prevented-a meager 8% or less than a 2% reduction in cases, depending on whether nonbacteremic pneumonia is included in the calculations. Although vaccination has had great success in some affluent countries, the current level of activity has had a very small impact globally. The use of conjugates, preferably with a reduced number of doses and in combination with other vaccines or perhaps in fractional doses, should be extended to less privileged countries, where most Hib disease occurs.

Introduction of Hib conjugate vaccines in the non-industrialized world: experience in four 'newly adopting' countries

Hib conjugate vaccines are widely used in the industrialized world, but are just now beginning to be introduced into other countries. To identify factors facilitating rapid global introduction, we evaluated the decision-making process, mode of introduction, effectiveness, and impact on the immunization program of Hib conjugate vaccine introduction in four non- industrialized countries through site visits and use of a standardized questionnaire. The key promoters of Hib introduction were the pediatric community and ministries of health. Local surveillance and severity data were critical in the decision to adopt Hib vaccine. Assistance with surveillance, introduction guidelines, educational material, tenders, and funding is needed to accelerate wider adoption.

Methodologic principles of cost analyses in the nursing, medical, and health services literature, 1990-1996

BACKGROUND

Cost analyses are needed to inform resource decisions. Oftentimes, however cost-benefit analysis (CBA), cost-effectiveness analysis (CEA), cost-minimization analysis (CMA), and cost-utility analysis (CUA) are performed using untested techniques and adhering to a variety of questionable principles.

OBJECTIVES

To analyze, compare, and present a set of useful principles for the main types and methods of cost analyses through a synthesis of current information in the published literature.

METHODS

The area of interest included all reports of cost research published as full articles in professional journals from January 1990 to August 1996 in the nursing, medical, and health services fields. In all, 88 sampled articles met the criteria for inclusion. A four-page data collection guide with 28 items grouped as demographics, cost-analysis types, methods, and principles was designed for the review. Incremental testing for interrater reliability using the kappa statistic for two raters was performed. Sampling, process-oriented, construct, and correlational validity were assessed.

RESULTS

The 88 articles included 4 from nursing, 59 from medical, and 25 from health services journals. Of these articles, 45 (51%) reported CBA, 36 (41%) CEA, 2 CMA, 4 CUA, and 1 both CBA and CEA. Three nursing studies were authored only by nurses. Three fourths of the medical and four fifths of the health services publications had interdisciplinary authorship. Existing databases were the primary source of data in 61 (69%) publications. Adherence to six main methodologic principles was apparent in 19 (22%) articles. None of the nursing studies adhered to all six principles, whereas 16% of the health services and 25% of the medical studies did.

CONCLUSIONS

Funded cost analyses of nursing interventions that adhere to the six known methodologic principles are needed to inform policy-level health care decisions. Because of the complexity of cost analysis methodology, including sensitivity analysis, future interdisciplinary efforts using existing databases may prove most effective. The six methodologic principles presented in this article can be useful for future nursing education and cost-analysis research designed to control cost and increase the quality of health care.

Cost-benefit analysis of Haemophilus influenzae type b vaccination in children in Spain

OBJECTIVE

Invasive disease caused by Haemophilus influenzae type b (Hib), including meningitis, pneumonia, sepsis and epiglottitis, is associated with high mortality and serious neurological sequelae in children under 5 years of age. The availability of an efficacious vaccine suggests the need to perform an economic evaluation of its use. The objective of this study was to evaluate the costs and benefits of introducing a universal vaccination programme for children under 1 year of age in Spain.

DESIGN & SETTING

A cost-benefit analysis (CBA) was conducted over a 5-year period from the societal perspective in the Spanish healthcare setting. Both direct and indirect costs were included in the analysis [using 1996 Spanish pesetas (Pta); Pta126.5 = $US1 in April 1996].

PATIENTS AND PARTICIPANTS

The target population used for cost and benefit estimation was the 384,883 Spaniards aged 1 year or less in the last Spanish Population and Housing Census of 1991.

MAIN OUTCOME MEASURES AND RESULTS

The introduction of the universal Hib vaccination programme would imply vaccinating 346,395 children under 1 year of age, with a global expense of Pta2,444,855,910. For an average incidence of 15 cases of invasive disease per 100,000 children per year nationwide, the programme would prevent 219 cases of invasive disease and 8 deaths over a 5-year period, with a benefit of Pta2,182,868,907, a net benefit (i.e. benefit minus cost) of -Pta261,987,003, a benefit/cost ratio of 0.89 and a benefit per case prevented of -Pta1,196,288. Benefit/cost ratios above 1 would be obtained in the regions of highest incidence of invasive disease.

CONCLUSION

The decision to implement a universal vaccination programme should not be based only on economic factors, but our results suggest that the economic returns of the programme for children under 1 year of age in Spain would be at least of a similar magnitude as its expenses.

An assessment of the value of Haemophilus influenzae type b conjugate vaccine in Asia

Haemophilus influenzae type b (Hib) is a leading cause of bacterial meningitis and pneumonia. Although invasive Hib disease has been reduced substantially wherever Hib conjugate vaccines have been introduced into routine childhood immunization schedules, these vaccines are more costly compared with the vaccines routinely used in the Expanded Program for Immunization. Consequently a model was constructed to compare the expected burden of Hib disease with and without a national vaccine program for various Asian countries. Cost of the vaccine program, expected benefits of reduced deaths and savings from prevented disease treatment were assessed for each country based on the model assumptions. Model outcomes were expressed as a net cost, cost per death prevented and cost per disability-adjusted life year for each country and economic stratum. With the assumption of a disease burden of meningitis and pneumonia comparable with that observed in other regions, the model predicts that 668000 cases of Hib pneumonia and 136000 cases of Hib meningitis would occur annually in this cohort resulting in 156000 deaths. Based on current vaccination coverage rates for the individual countries, the model predicted that approximately 136000 (87%) Hib deaths could be prevented annually with incorporation of Hib vaccine into the Expanded Program for Immunization. For each of the countries considered, routine vaccination with Hib would cost between 0.1 and 3.0% of per capita gross national product per child <5 years of age. Although Hib vaccine would be considered a cost-effective public health intervention, it may be cost-prohibitive to implement in the lowest income countries without initial donor assistance.

The introduction of routine Haemophilus influenzae type b conjugate vaccine in Chile: a framework for evaluating new vaccines in newly industrializing countries

OBJECTIVE

To determine the burden of Haemophilus influenzae type b (Hib) disease, the safety and immunogenicity of Hib conjugate vaccine, the practicality of combining Hib conjugate and diphtheria-tetanus-pertussis vaccines and the effectiveness of routine vaccination.

STUDY DESIGNS

A series of studies were carried out involving infants and children in Santiago, Chile. The study designs included retrospective surveillance, cost-benefit analysis, randomized placebo-controlled trials of safety and immunogenicity and a Phase IV postlicensure evaluation of vaccine effectiveness.

RESULTS

The studies included in this stepwise process showed that Hib invasive disease was a significant public health problem with a substantial economic burden; that combining Hib conjugate and diphtheria-tetanus-pertussis vaccines was practical, safe and elicited a strong immunologic response; and that the combined formulation afforded a high level of protection against invasive Hib disease (90% effectiveness).

CONCLUSIONS

In July, 1996, Chile became only the third newly industrializing country to introduce routine Hib conjugate vaccination. New vaccines, such as Hib conjugates, will be more expensive than existing ones. The stepwise process used in Chile may serve as an example for the evaluation of new vaccines in nonindustrialized countries.

Economisation of vaccination against Haemophilus influenzae type b: a randomised trial of immunogenicity of fractional-dose and two-dose regimens

BACKGROUND

The cost of Haemophilus influenzae type b (Hib) conjugate vaccines has limited their use in non-industrialised countries. To identify more economical vaccination schedules, we carried out a randomised trial of the immunogenicity of alternative regimens to the standard three-dose series.

METHODS

627 Chilean infants were randomly allocated to one of four regimens with either Hib polysaccharide-tetanus toxoid conjugate vaccine (PRP-T) or Hib oligosaccharide-diphtheria mutant toxoid conjugate vaccine (PRP-CRM197), for a total of eight groups. All infants receive diphtheria-tetanus-pertussis (DTP) vaccine at ages 2, 4, and 6 months. The regimens included three full doses, three fractional doses consisting of one half or one third of the full dose, and a regimen of two full doses (at age 4 and 6 months). The primary outcome was the proportion of infants with serum anti-polyribosylribitol phosphate (PRP, the type b capsular polysaccharide) concentrations of 0.15 microg/mL or more at age 8 months.

FINDINGS

93% (95% CI 85-98) of infants vaccinated with three full doses of PRP-T or PRP-CRM197 (95% CI 84-98) achieved anti-PRP concentrations of 0.15 microg/mL or more at age 8 months, compared with 91% (83-96) to 100% (95-100) of infants immunised with any fractional-dose regimen. Of the infants vaccinated with two doses of PRP-T or PRP-CRM197, 99% (93-100) and 87% (77-93) developed anti-PRP concentrations of 0.15 microg/mL or more, respectively.

INTERPRETATION

91% (83-96) to 100% (95-100) of infants immunised with one-half or one-third of a full dose of Hib conjugate developed protective antibody concentrations. Carrier priming with DTP may make two-dose schedules an option in some places. These alternative regimens could bring the cost of Hib vaccines within reach of countries that currently cannot afford them.

Cost-benefit analyses in the health-care literature: don't judge a study by its label

OBJECTIVES

To assess whether health-care related economic evaluations labeled as "cost benefit analyses" (CBA) meet a contemporary definition of CBA methodology and to assess the prevalence of methods used for assigning monetary units to health outcomes.

DATA SOURCES

Medline, Current Contents, and HSTAR databases and reference lists of review articles, 1991-1995.

STUDY SELECTION

Economic analyses labeled as CBAs were included. Agreement on study selection was assessed. STUDY EVALUATION: CBA studies were classified according to standard definitions of economic analytical techniques. For those valuing health outcomes in monetary units (bona fide CBAs), the method of valuation was classified.

RESULTS

53% of 95 studies were reclassified as cost comparisons because health outcomes were not appraised. Among the 32% considered bona fide CBAs, the human capital approach was employed to value health states in monetary units in 70%. Contingent valuation methods were employed infrequently (13%).

CONCLUSIONS

Studies labeled as CBAs in the health-care literature often offer only partial program evaluation. Decisions based only on resource costs are unlikely to improve efficiency in resource allocation. Among bona fide CBAs, the human capital approach was most commonly used to valuing health, despite its limitations. The results of health-care related CBAs should be interpreted with extreme caution.

Large scale, postlicensure, selective vaccination of Chilean infants with PRP-T conjugate vaccine: practicality and effectiveness in preventing invasive Haemophilus influenzae type b infections

BACKGROUND

Haemophilus influenzae type b (Hib) conjugate vaccines have demonstrated an impressive impact in diminishing Hib disease in industrialized countries. However, their high cost prompts nonindustrialized countries to corroborate their effectiveness under local conditions before considering their programmatic implementation. Such a postlicensure evaluation of vaccine effectiveness was undertaken in Chile.

METHODS

After its licensure in Chile polyribosylribitol phosphate-tetanus toxoid protein conjugate vaccine (PRP-T), combined with diphtheria-tetanus-pertussis vaccine, was introduced into the Expanded Program on Immunization schedules in 36 health centers throughout metropolitan Santiago for 12 months, whereas 35 similar health centers administered only diphtheria-tetanus toxoid-pertussis vaccine. Bacteriologic surveillance data for invasive Hib cases collected over the ensuing 30 months were analyzed.

RESULTS

In an intent-to-vaccinate (effectiveness) analysis, PRP-T provided 90.2% protection (95% confidence interval, 74.5 to 100%) against invasive Hib disease (40 vs. 4 cases, P < 0.001). Vaccine effectiveness was 91.3% against meningitis (22 vs. 2 cases) and 80% against pneumonia and empyema (10 vs. 2 cases, P = 0.039). Vaccine efficacy among infants who received all three doses of PRP-T was 91.7% (95% confidence interval, 64.8 to 100%).

CONCLUSIONS

Programmatic use of Hib conjugate vaccine administered in combination with diphtheria-tetanus-pertussis vaccine constitutes a highly effective and practical intervention in Chile, a newly industrializing country.

Economic aspects of a general vaccination against invasive disease caused by Haemophilus influenzae type b (Hib) via the experience of the Children's Hospital La Fe, Valencia, Spain

With the aim of studying whether a general vaccination against invasive disease caused by Haemophilus influenzae type b (Hib) is economically profitable bearing in mind the efficacy and safety of the vaccine, its price and the global cost that this disease has in our area, a review is conducted of patients admitted due to invasive disease caused by Hib in the Children's Hospital La Fe, Valencia, born between 1984 and 1993. They total 100, 63 who have meningitis. In the 81 cases (56 with meningitis) born between 1984 and 1990 (years that can be regarded as "closed" since all the patients were younger than 5 years of age) the total cost has been calculated for hospitalization, care during the acute phase, care for the sequelae (6 severe and 7 mild) and death (5 cases). The mean annual cost of care can be calculated at 62 million pesetas, without making an economic valuation of the loss of life, and at 205 million pesetas taking this factor into account. The annual cost of vaccinating the 7000 babies under one year of age and falling within the Hospital's catchment area, on the basis of a vaccination pattern of three doses (at 2, 4 and 6 months) or four doses (at 2, 4, 6 and 15 months) would amount to 63 or 84 million pesetas, normal price to public (not covered by National Health Service), and 40 or 51 million pesetas if acquired by National Health Service. As a conclusion we can state that, even from the economic point of view, without quantifying the cost of the loss of life, a public general anti-Hib vaccination would be profitable in our area since it would mean an administration cost lower than that of the care required by patients. This is without taking into account the fact that emotional, family and social serious disturbances would also be avoided due to hospitalization, sequelae and deaths caused by a disease which is today perfectly preventable.