Critical issues in the economic evaluation of interventions against communicable diseases

An economic analysis of malaria elimination program in Nepal

BACKGROUND

Governments have committed to eliminate malaria. But a decline in government investment in malaria interventions, particularly in developing countries such as Nepal, reveals a limited emphasis on malaria elimination that may be due to lack of strong evidence on benefits of the investment. This paper empirically analyses curative and preventive costs and benefits of Nepal's malaria elimination program from the perspectives of both service providers in the public sector and people who are at risk.

METHODS

Cost benefit analysis of both curative and preventive interventions for malaria elimination was conducted using case and non-case household survey data. Secondary data were obtained from government sources. Ingredient approach and step-down methods were used to estimate costs of malaria elimination interventions, and willingness to pay (WTP) method and case averted approach to estimate benefits.

RESULTS

Curative intervention of malaria elimination program is economically viable in Nepal with a net present value (NPV) of USD 23 million, benefit cost ratio (BCR) of 1.58 and internal rate of return of 63%. Malaria preventive intervention is highly beneficial with NPV of USD 435 million and BCR of 2.13. An annual investment of USD 36.59 million is required to continue the current pattern of malaria reduction that can generate societal benefits of USD 92.81 million. From this investment, the government can save USD 132 million by the end of 2025. The maximum WTP of case households for the intervention is USD 57 per household which is 63% higher than that of non-case households.

CONCLUSION

Malaria elimination program in Nepal is economically viable and investment worthy. As the preventive intervention generates much higher net benefits than the curative intervention, the government should emphasize on preventive intervention while continuing the curative interventions.

Identifying priority technical and context-specific issues in improving the conduct, reporting and use of health economic evaluation in low- and middle-income countries

Background

The use of economic evaluation in healthcare policies and decision-making, which is limited in low- and middle-income countries (LMICs), might be promoted through the improvement of the conduct and reporting of studies. Although the literature indicates that there are many issues affecting the conduct, reporting and use of this evidence, it is unclear which factors should be prioritised in finding solutions. This study aims to identify the top priority issues that impede the conduct, reporting and use of economic evaluation as well as potential solutions as an input for future research topics by the international Decision Support Initiative and other movements.

Methods

A survey on issues regarding the conduct, reporting and use of economic evaluation as well as on potential solutions was conducted using an online questionnaire among researchers who have experience in conducting economic evaluations in LMICs. The respondents were requested to consider the list of issues provided, rank the most important ones and propose solutions. A scoring system was applied to derive the ranking of difficulties according to researchers’ responses. Issues were grouped into technical and context-specific difficulties and analysed separately as a whole and by region.

Results

Researchers considered the lack of quality local clinical data, poor reporting and insufficient data to conduct the analysis from the chosen perspective as the most important technical difficulties. On the other hand, the non-integration of economic evaluations into decision-making was considered the most important context-specific issue. Finally, context-specific issues were considered the larger barrier to the use of economic evaluation.

Conclusion

The technical issues that were considered most important were closely linked with the lack of an appropriately functioning information system as well as the capacity to generate essential contextual information (e.g. data and locally relevant utility values), especially when the methodology is complex. To overcome this, simpler approaches to collect data that yields information of comparable quality to more rigorous methods should be developed. The international community can play a major role through research on methodologies feasible for LMIC settings as well as in building research capacity in countries. Context-specific issues, which were recognised as larger barriers, should be improved in parallel.

Electronic supplementary material

The online version of this article (10.1186/s12961-018-0280-6) contains supplementary material, which is available to authorized users.

Selecting a mix of prevention strategies against cervical cancer for maximum efficiency with an optimization program

BACKGROUND

Screening and vaccination against human papillomavirus (HPV) can protect against cervical cancer. Neither alone can provide 100% protection. Consequently it raises the important question about the most efficient combination of screening at specified time intervals and vaccination to prevent cervical cancer.

OBJECTIVE

Our objective was to identify the mix of cervical cancer prevention strategies (screening and/or vaccination against HPV) that achieves maximum reduction in cancer cases within a fixed budget.

METHODS

We assessed the optimal mix of strategies for the prevention of cervical cancer using an optimization program. The evaluation used two models. One was a Markov cohort model used as the evaluation model to estimate the costs and outcomes of 52 different prevention strategies. The other was an optimization model in which the results of each prevention strategy of the previous model were entered as input data. The latter model determined the combination of the different prevention options to minimize cervical cancer under budget, screening coverage and vaccination coverage constraints. We applied the model in two countries with different healthcare organizations, epidemiology, screening practices, resource settings and treatment costs: the UK and Brazil. 100,000 women aged 12 years and above across the whole population over a 1-year period at steady state were included. The intervention was papanicolaou (Pap) smear screening programmes and/or vaccination against HPV with the bivalent HPV 16/18 vaccine (Cervarix® [Cervarix is a registered trademark of the GlaxoSmithKline group of companies]). The main outcome measures were optimal distribution of the population between different interventions (screening, vaccination, screening plus vaccination and no screening or vaccination) with the resulting number of cervical cancer and associated costs.

RESULTS

In the base-case analysis (= same budget as today), the optimal prevention strategy would be, after introducing vaccination with a coverage rate of 80% in girls aged 12 years and retaining screening coverage at pre-vaccination levels (65% in the UK, 50% in Brazil), to increase the screening interval to 6 years (from 3) in the UK and to 5 years (from 3) in Brazil. This would result in a reduction of cervical cancer by 41% in the UK and by 54% in Brazil from pre-vaccination levels with no budget increase. Sensitivity analysis shows that vaccination alone at 80% coverage with no screening would achieve a cervical cancer reduction rate of 20% in the UK and 43% in Brazil compared with the pre-vaccination situation with a budget reduction of 30% and 14%, respectively. In both countries, the sharp reduction in cervical cancer is seen when the vaccine coverage rate exceeds the maximum screening coverage rate, or when screening coverage rate exceeds the maximum vaccine coverage rate, while maintaining the budget. As with any model, there are limitations to the value of predictions depending upon the assumptions made in each model.

CONCLUSIONS

Spending the same budget that was used for screening and treatment of cervical cancer in the pre-vaccination era, results of the optimization program show that it would be possible to substantially reduce the number of cases by implementing an optimal combination of HPV vaccination (80% coverage) and screening at pre-vaccination coverage (65% UK, 50% Brazil) while extending the screening interval to every 6 years in the UK and 5 years in Brazil.

Modelling the epidemiology of infectious diseases for decision analysis: a primer

The number of economic evaluations related to infectious disease topics has increased over the last 2 decades. However, many such evaluations rely on models that do not take into account unique features of infectious diseases that can affect the estimated value of interventions against them. These include their transmissibility from infected to susceptible individuals, the possibility of acquiring natural immunity following recovery from infection and the uncertainties that arise as a result of their complex natural history and epidemiology. Modellers conducting economic evaluations of infectious disease interventions need to know the main features of different types of infectious disease models, the situations in which they should be applied and the effects of model choices on the cost effectiveness of interventions.

Modeling the cost-effectiveness of the integrated disease surveillance and response (IDSR) system: meningitis in Burkina Faso

Background

Effective surveillance for infectious diseases is an essential component of public health. There are few studies estimating the cost-effectiveness of starting or improving disease surveillance. We present a cost-effectiveness analysis the Integrated Disease Surveillance and Response (IDSR) strategy in Africa.

Methodology/Principal Findings

To assess the impact of the IDSR in Africa, we used pre- and post- IDSR meningococcal meningitis surveillance data from Burkina Faso (1996–2002 and 2003–2007). IDSR implementation was correlated with a median reduction of 2 weeks to peak of outbreaks (25^th percentile 1 week; 75^th percentile 4 weeks). IDSR was also correlated with a reduction of 43 meningitis cases per 100,000 (25^th–40: 75^th-129). Assuming the correlations between reductions in time to peak of outbreaks and cases are related, the cost-effectiveness of IDSR was $23 per case averted (25^th-$30; 75^th - cost saving), and $98 per meningitis-related death averted (25^th-$140: 75^th – cost saving).

Conclusions/Significance

We cannot absolutely claim that the measured differences were due to IDSR. We believe, however, that it is reasonable to claim that IDSR can improve the cost-effectiveness of public health surveillance.

Cost analysis of an integrated disease surveillance and response system: case of Burkina Faso, Eritrea, and Mali

Background

Communicable diseases are the leading causes of illness, deaths, and disability in sub-Saharan Africa. To address these threats, countries within the World Health Organization (WHO) African region adopted a regional strategy called Integrated Disease Surveillance and Response (IDSR). This strategy calls for streamlining resources, tools, and approaches to better detect and respond to the region's priority communicable disease. The purpose of this study was to analyze the incremental costs of establishing and subsequently operating activities for detection and response to the priority diseases under the IDSR.

Methods

We collected cost data for IDSR activities at central, regional, district, and primary health care center levels from Burkina Faso, Eritrea, and Mali, countries where IDSR is being fully implemented. These cost data included personnel, transportation items, office consumable goods, media campaigns, laboratory and response materials and supplies, and annual depreciation of buildings, equipment, and vehicles.

Results

Over the period studied (2002–2005), the average cost to implement the IDSR program in Eritrea was $0.16 per capita, $0.04 in Burkina Faso and $0.02 in Mali. In each country, the mean annual cost of IDSR was dependent on the health structure level, ranging from $35,899 to $69,920 at the region level, $10,790 to $13,941 at the district level, and $1,181 to $1,240 at the primary health care center level. The proportions spent on each IDSR activity varied due to demand for special items (e.g., equipment, supplies, drugs and vaccines), service availability, distance, and the epidemiological profile of the country.

Conclusion

This study demonstrates that the IDSR strategy can be considered a low cost public health system although the benefits have yet to be quantified. These data can also be used in future studies of the cost-effectiveness of IDSR.

Using cost-effectiveness analyses to inform policy: the case of antiretroviral therapy in Thailand

Background:

Much emphasis is put on providing evidence to assist policymakers in priority setting and investment decisions. Assessing the cost-effectiveness of interventions is one technique used by policymakers in their decisions around the allocation of scarce resources. However, even where such evidence is available, other considerations may also be taken into account, and even over-ride technical evidence. Antiretroviral therapy (ART) is the most effective intervention to reduce HIV-related morbidity and prolong mortality. However, treatment provision in the developing world has been hindered by the high costs of services and drugs, casting doubts on its cost-effectiveness. This paper looks at Thailand's publicly-funded antiretroviral initiative which was first introduced in 1992, and explores the extent to which cost-effectiveness evidence influenced policy.

Methods:

This article reviews the development of the national ART programme in Thailand between 1992 and 2004. It examines the roles of cost-effectiveness information in treatment policy decisions. Qualitative approaches including document analysis and interview of key informants were employed.

Results:

Two significant policy shifts have been observed in government-organised ART provision. In 1996, service-based therapy for a few was replaced by a research network to support clinical assessments of antiretroviral medication in public hospitals. This decision was taken after a domestic study illustrated the unaffordable fiscal burden and inefficient use of resources in provision of ART. The numbers of treatment recipients was maintained at 2,000 per year throughout the 1990s. It was not until 2001 that a new government pledged to extend the numbers receiving the service, as part of its commitment to universal coverage. Several elements played a role in this decision: new groups of dominant actors, drug price reductions, a pro-active civil society movement, lessons from experience on treatment benefits, and global treatment advocacy. Unlike previous policy discourse, human rights, ethics and equity notions were explicitly raised to support therapy extension.

Conclusion:

In the early decision, moving from a relatively limited ART service to a research network was clearly influenced by cost-effectiveness data. But in the 2001 decision to include ART in the universal coverage package, cost-effectiveness arguments were over-ruled by other considerations. Thai ART policy was shaped by many factors, and was not a simple rational process which relied on evidence.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Thiomersal in Vaccines

A number of affluent countries are moving to eliminate thiomersal (thimerosal), an ethylmercury preservative, from vaccines as a precautionary measure because of concerns about the potential adverse effects of mercury in infants. The WHO advocates continued use of thiomersal-containing vaccines in developing countries because of their effectiveness, safety, low cost, wide availability and logistical suitability in this setting. The guidelines for long-term mercury exposure should not be used for evaluating risk from intermittent single day exposures, such as immunisation using thiomersal-containing vaccines. Similar or higher mercury exposures likely occur from breast feeding and the health benefit of eliminating thiomersal from a vaccine, if any, is likely to be very small. On the other hand, the benefits accrued from the use of thiomersal-containing vaccines are considerably greater but vary substantially between affluent and developing regions of the world. Because of the contribution to overall mercury exposure from breast milk and diet in later life, the removal of thiomersal from vaccines would produce no more than a 50% reduction of mercury exposure in infancy and <1% reduction over a lifetime. Different public policy decisions are appropriate in different settings to achieve the lowest net risk, viewed from the perspectives of the individual vaccinee or on a population basis. In developing regions of the world, at least over the next decade, far more benefit will accrue from protecting children against widely prevalent vaccine-preventable diseases by focusing efforts aimed at improving infant immunisation uptake by using current, inexpensive, domestically-manufactured, thiomersal-containing vaccines, than by investing in thiomersal-free alternatives.

Strengthening health services to control epidemics: empirical evidence from Guinea on its cost-effectiveness

OBJECTIVE

To assess the cost-effectiveness of control measures implemented against epidemics in Guinea, West Africa.

METHODS

We collected all routine data available on incidence, mortality, control measures implemented and their cost during epidemics of cholera, measles and meningococcal meningitis in 1993-95. Then we estimated for one prefecture the effectiveness and cost-effectiveness of epidemic control measures for three scenarios: (i) 'natural' situation, (ii) 'routine' health services and (iii) 'intervention'. Where uncertainty was considerable, we used sensitivity analysis and estimated ranges.

FINDINGS

Routine health services reduced potential deaths by 51% (67%, 37% and 60% for cholera, measles and meningitis, respectively), and additional interventions further decreased potential deaths by 28% (28%, 27% and 30% for cholera, measles and meningitis, respectively). The marginal cost-effectiveness of epidemic control measures in routine health services was US dollars 29 per death averted. The marginal cost-effectiveness of additional interventions was US dollars 93 per death averted.

CONCLUSION

Even with the data weaknesses that characterize situations of epidemics it is possible to show that strengthening health services to control epidemics as was performed in Guinea was highly cost-effective. Moreover, sensitivity analysis over a range of assumptions confirms that (i) well-functioning health services averted the major part of avoidable deaths, (ii) combining existing health services with additional interventions minimizes the health impact of epidemics and (iii) case management should be a cornerstone of control of epidemics of cholera, measles and meningococcal meningitis.

Using burden of disease information for health planning in developing countries: the experience from Uganda

Given the growing interest in both the use of evidence in planning and in using the burden of disease measure (BOD) and cost-effectiveness analysis, we explored health planners' perception of the usefulness of the BOD in priority setting and planning in developing countries, using Uganda as an example. An exploratory qualitative approach involving in-depth interviews with key policy makers in health at district and national levels was employed. Interviews were supplemented with a review of relevant documents. Analysis involved identification of key concepts from the interviews. Concepts were grouped into categories, namely, the appeal of quantitative data, data limitations, opaque methodology, planning as a political process and opportunity costs. These form the basis of this article. We found that the BOD study results have been used as the basis for the national health policy and in defining the contents of the national essential health care package. The quantification and ranking of disease burden is appreciated by politicians and used for advocacy, resource mobilization and re-allocation. The results have also provided information for priority setting and strategic planning. Limitations to its use included poor understanding of the methodology, poor quality of data in-puts, low involvement of stakeholders, inability of the methodology to capture key non-economic issues, and the costs of carrying out the study. There is commitment, by Ugandan planners to using evidence in priority setting. Since this was an exploratory study, there is a need for more studies in developing countries to document their experiences with the use of evidence, and specifically, the BOD approach in planning and priority setting. Such information would contribute to further synthesis of the approach.

Combination therapy for malaria: the way forward?

Unless new strategies are deployed to combat malaria, the already enormous health and economic burden related to the disease in tropical countries is bound to worsen. The main obstacle to malaria control is the emergence of drug resistant strains of Plasmodium falciparum. As for HIV/AIDS and tuberculosis, the use of combinations of antimalarial drugs reduces the risk of selecting for resistant mutants of the plasmodial parasites. In large field trials, the combination of an artemisinin derivative and a partner drug with an unrelated mode of action (in this case mefloquine), has shown a remarkable double effect: preventing the emergence and spread of drug resistance, and interrupting the transmission of P. falciparum. This has opened the way for a new approach to the deployment of antimalarial drugs. Coupled with early detection and confirmed diagnosis, this strategy represents the only way forward in the chemotherapy of malaria. Massive economic assistance will be needed to detect and treat adequately the estimated 500 million cases of malaria per year, but without radical action there is no prospect of 'Rolling Back' malaria.

Efficacy and cost-effectiveness of environmental management for malaria control

Roll back malaria (RBM) aims at halving the current burden of the disease by the year 2010. The focus is on sub-Saharan Africa, and it is proposed to implement efficacious and cost-effective control strategies. But the evidence base of such information is scarce, and a notable missing element is the discussion of the potential of environmental management. We reviewed the literature and identified multiple malaria control programmes that incorporated environmental management as the central feature. Prominent among them are programmes launched in 1929 and implemented for two decades at copper mining communities in Zambia. The full package of control measures consisted of vegetation clearance, modification of river boundaries, draining swamps, oil application to open water bodies and house screening. Part of the population also was given quinine and was sleeping under mosquito nets. Monthly malaria incidence rates and vector densities were used for surveillance and adaptive tuning of the environmental management strategies to achieve a high level of performance. Within 3-5 years, malaria-related mortality, morbidity and incidence rates were reduced by 70-95%. Over the entire 20 years of implementation, the programme had averted an estimated 4173 deaths and 161,205 malaria attacks. The estimated costs per death and malaria attack averted were US$ 858 and US$ 22.20, respectively. Over the initial 3-5 years start-up period, analogous to the short-duration of cost-effectiveness analyses of current studies, we estimated that the costs per disability adjusted life year (DALY) averted were US$ 524-591. However, the strategy has a track record of becoming cost-effective in the longer term, as maintenance costs were much lower: US$ 22-92 per DALY averted. In view of fewer adverse ecological effects, increased sustainability and better uses of local resources and knowledge, environmental management--integrated with pharmacological, insecticidal and bednet interventions--could substantially increase the chances of rolling back malaria.