Considering equity in priority setting using transmission models: Recommendations and data needs.

OBJECTIVES: Disease transmission models are used in impact assessment and economic evaluations of infectious disease prevention and treatment strategies, prominently so in the COVID-19 response. These models rarely consider dimensions of equity relating to the differential health burden between individuals and groups. We describe concepts and approaches which are useful when considering equity in the priority setting process, and outline the technical choices concerning model structure, outputs, and data requirements needed to use transmission models in analyses of health equity. METHODS: We reviewed the literature on equity concepts and approaches to their application in economic evaluation and undertook a technical consultation on how equity can be incorporated in priority setting for infectious disease control. The technical consultation brought together health economists with an interest in equity-informative economic evaluation, ethicists specialising in public health, mathematical modellers from various disease backgrounds, and representatives of global health funding and technical assistance organisations, to formulate key areas of consensus and recommendations. RESULTS: We provide a series of recommendations for applying the Reference Case for Economic Evaluation in Global Health to infectious disease interventions, comprising guidance on 1) the specification of equity concepts; 2) choice of evaluation framework; 3) model structure; and 4) data needs. We present available conceptual and analytical choices, for example how correlation between different equity- and disease-relevant strata should be considered dependent on available data, and outline how assumptions and data limitations can be reported transparently by noting key factors for consideration. CONCLUSIONS: Current developments in economic evaluations in global health provide a wide range of methodologies to incorporate equity into economic evaluations. Those employing infectious disease models need to use these frameworks more in priority setting to accurately represent health inequities. We provide guidance on the technical approaches to support this goal and ultimately, to achieve more equitable health policies.

Cost of TB services: approach and summary findings of a multi-country study (Value TB).

BACKGROUND: There are currently large gaps in unit cost data for TB, and substantial variation in the quality and methods of unit cost estimates. Uncertainties remain about sample size, range and comprehensiveness of cost data collection for different purposes. We present the methods and results of a project implemented in Kenya, Ethiopia, India, The Philippines and Georgia to estimate unit costs of TB services, focusing on findings most relevant to these remaining methodological challenges.METHODS: We estimated financial and economic unit costs, in close collaboration with national TB programmes. Gold standard methods included both top-down and bottom-up approaches to resource use measurement. Costs are presented in 2018 USD and local currency unit.RESULTS: Cost drivers of outputs varied by service and across countries, as did levels of capacity inefficiency. There was substantial variation in unit cost estimates for some interventions and high overhead costs were observed. Estimates were subject to sampling uncertainty, and some data gaps remain.CONCLUSION: This paper describes detailed methods for the largest TB costing effort to date, to inform prioritisation and planning for TB services. This study provides a strong baseline and some cost estimates may be extrapolated from this data; however, regular further studies of similar quality are needed to add estimates for remaining gaps, or to add new or changing services and interventions. Further research is needed on the best approach to extrapolation of cost data. Costing studies are best implemented as partnerships with policy makers to generate a community of mutual learning and capacity development.

Cost of tuberculosis treatment in low- and middle-income countries: systematic review and meta-regression.

BACKGROUND: Despite a scarcity of tuberculosis (TB) cost data, a substantial body of evidence has been accumulating for drug-susceptible TB (DS-TB) treatment. In this study, we review unit costs for DS-TB treatment from a provider´s perspective. We also examine factors driving cost variations and extrapolate unit costs across low- and middle-income countries (LMICs).METHODS: We searched published and grey literature for any empirically collected TB cost estimates. We selected a subgroup of estimates looking at DS-TB treatment. We extracted information on activities and inputs included. We standardised costs into an average per person-month, fitted a multi-level regression model and cross-validated country-level predictions. We then extrapolated estimates for facility-based, directly observed DS-TB treatment across countries.RESULTS: We included 95 cost estimates from 28 studies across 17 countries. Costs predictions were sensitive to characteristics such as delivery mode, whether hospitalisation was included, and inputs accounted for, as well as gross domestic product per capita. Extrapolation results are presented with uncertainty intervals (UIs) for LMICs. Predicted median costs per 6 months of treatment were US$315.30 (95% CI US$222.60-US$417.20) for low-income, US$527.10 (95% CI US$395.70-US$743.70) for lower middle-income and US$896.40 (95% CI US$654.00-US$1214.40) for upper middle-income countries.CONCLUSIONS: Our study provides country-level DS-TB treatment cost estimates suitable for priority setting. These estimates, while not standing as a substitute for local high-quality primary data, can inform global, regional and national exercises.

Improving the quality of modelling evidence used for tuberculosis policy evaluation.

Mathematical modelling is commonly used to evaluate policy options for tuberculosis (TB) control in high-burden countries. Although major policy and funding decisions are made based on these analyses, there is concern about the variability of results produced using modelled policy analyses. We discuss new guidance for country-level TB policy modelling. The guidance was developed by the TB Modelling and Analysis Consortium in collaboration with the World Health Organization Global TB Programme, with input from a range of TB stakeholders (funders, modelling groups, country TB programme staff and subject matter experts). The guidance describes principles for country-level TB modelling, as well as good practices for operationalising the principles. The principles cover technical concerns such as model design, parameterisation and validation, as well as approaches for incorporating modelling into country-led policy making and budgeting. For modellers, this guidance suggests approaches to improve the quality and relevance of modelling undertaken to support country-level planning. For non-modellers, this guidance describes considerations for engaging modelling technical assistance, contributing to a modelling exercise and reviewing the results of modelled analyses. If routinely adopted, this guidance should improve the reliability, transparency and usefulness of modelling for country-level TB policy making. However, this guidance will not address all challenges facing modelling, and ongoing work is needed to improve the empirical evidence base for TB policy evaluation and develop stronger mechanisms for validating models. Increasing country ownership of the modelling process remains a challenge, requiring sustained engagement and capacity building.

Access to and utilisation of healthcare services by sex workers at truck-stop clinics in South Africa: A case study.

BACKGROUND: Sex worker-specific health services aim to respond to the challenges that this key population faces in accessing healthcare. These services aim to integrate primary healthcare (PHC) interventions, yet most services tend to focus on prevention of HIV and sexually transmitted infections (STIs). North Star Alliance (North Star) is a public-private partnership providing a healthcare service package in roadside wellness clinics (RWCs) to at-risk populations along transport corridors in sub-Saharan Africa. OBJECTIVES: To inform future service development for sex workers and describe North Star's contribution to healthcare provision to this population in South Africa, we describe services provided to and utilised by sex workers, and their views of these services. METHODS: Using a mixed-methods approach, we present quantitative analyses of anonymised North Star routine data for sex workers for October 2013 - September 2015, covering nine sites in seven provinces. Clinic visits were disaggregated by type of service accessed. We performed thematic analysis of 25 semi-structured interviews conducted at five clinics. RESULTS: A total of 2 794 sex workers accessed RWCs during the 2 years. Sex workers attending clinics were almost exclusively female (98.2%) and aged <40 years (83.8%). The majority were South African (83.8%), except at Musina, where the majority of clients were Zimbabwean. On average, sex workers visited the clinics 1.5 times per person. However, in most cases only one service was accessed per visit. PHC services other than for HIV and STIs were accessed more commonly than HIV-specific services and STI treatment. There was an increase in the number of services accessed over time, the figure almost doubling from 1 489 during the first year to 2 936 during the second year. Although during recruitment participants reported having had sex in exchange for goods or money during the past 3 months, not all participants self-identified as sex workers during interviews; however, all reported feeling at higher risk of poor health than the general population owing to their involvement in sex work. Participants reported satisfaction with site accessibility, location and operating hours. Sex workers accessing sites described services as being suitable and accessible, with friendly staff. CONCLUSIONS: RWCs were highly appreciated by the users, as they are suitable and accessible. The sex workers who used the clinics visited them irregularly, mostly for PHC services other than HIV and STIs. Services other than the one for which the sex worker came to the clinic rarely appeared to be offered. We recommend areas for service expansion.

Cost and cost-effectiveness of tuberculosis treatment shortening: a model-based analysis.

BACKGROUND: Despite improvements in treatment success rates for tuberculosis (TB), current six-month regimen duration remains a challenge for many National TB Programmes, health systems, and patients. There is increasing investment in the development of shortened regimens with a number of candidates in phase 3 trials. METHODS: We developed an individual-based decision analytic model to assess the cost-effectiveness of a hypothetical four-month regimen for first-line treatment of TB, assuming non-inferiority to current regimens of six-month duration. The model was populated using extensive, empirically-collected data to estimate the economic impact on both health systems and patients of regimen shortening for first-line TB treatment in South Africa, Brazil, Bangladesh, and Tanzania. We explicitly considered 'real world' constraints such as sub-optimal guideline adherence. RESULTS: From a societal perspective, a shortened regimen, priced at USD1 per day, could be a cost-saving option in South Africa, Brazil, and Tanzania, but would not be cost-effective in Bangladesh when compared to one gross domestic product (GDP) per capita. Incorporating 'real world' constraints reduces cost-effectiveness. Patient-incurred costs could be reduced in all settings. From a health service perspective, increased drug costs need to be balanced against decreased delivery costs. The new regimen would remain a cost-effective option, when compared to each countries' GDP per capita, even if new drugs cost up to USD7.5 and USD53.8 per day in South Africa and Brazil; this threshold was above USD1 in Tanzania and under USD1 in Bangladesh. CONCLUSION: Reducing the duration of first-line TB treatment has the potential for substantial economic gains from a patient perspective. The potential economic gains for health services may also be important, but will be context-specific and dependent on the appropriate pricing of any new regimen.

A simplified cost-effectiveness model to guide decision-making for shortened anti-tuberculosis treatment regimens.

User-friendly models (UFMs) allow local decision makers to explore relationships and apply results from more detailed models of such outcomes as cost-effectiveness. When developing UFMs, modelers must decide which simplifications may be appropriate, enabling the UFM to retain accuracy while reducing complexity. We use the example of cost-effectiveness analysis (CEA) for novel shortened anti-tuberculosis treatment regimens across four settings to demonstrate how UFMs can allow decision makers to adapt published results to their local context. We simplified a complex model to produce a UFM that provides similar results, the ability to modify key parameter values, and receive customized results in seconds.

Cutting the cost of South African antiretroviral therapy using newer, safer drugs.

Antiretrovirals are a significant cost driver for HIV programmes. Current first-line regimens have performed well in real-life programmes, but have a low barrier to virological resistance and still carry toxicity that limits adherence. New drug developments may mean that we have access to safer, more robust and cheaper regimens, but only if the appropriate clinical trials are conducted. We briefly discuss these trials, and demonstrate the large cost savings to the South African HIV programme if these are successful.

Impact and cost-effectiveness of current and future tuberculosis diagnostics: the contribution of modelling.

The landscape of diagnostic testing for tuberculosis (TB) is changing rapidly, and stakeholders need urgent guidance on how to develop, deploy and optimize TB diagnostics in a way that maximizes impact and makes best use of available resources. When decisions must be made with only incomplete or preliminary data available, modelling is a useful tool for providing such guidance. Following a meeting of modelers and other key stakeholders organized by the TB Modelling and Analysis Consortium, we propose a conceptual framework for positioning models of TB diagnostics. We use that framework to describe modelling priorities in four key areas: Xpert(®) MTB/RIF scale-up, target product profiles for novel assays, drug susceptibility testing to support new drug regimens, and the improvement of future TB diagnostic models. If we are to maximize the impact and cost-effectiveness of TB diagnostics, these modelling priorities should figure prominently as targets for future research.

North-South Corridor Demonstration Project: Ethical and Logistical Challenges in the Design of a Demonstration Study of Early Antiretroviral Treatment for Long Distance Truck Drivers along a Transport Corridor through South Africa, Zimbabwe, and Zambia.

Background. Long-distance truck drivers are at risk of acquiring and transmitting HIV and have suboptimal access to care. New HIV prevention strategies using antiretroviral drugs to reduce transmission risk (early antiretroviral therapy (ART) at CD4 count >350 cells/ µ L) have shown efficacy in clinical trials. Demonstration projects are needed to evaluate "real world" programme effectiveness. We present the protocol for a demonstration study to evaluate the feasibility, acceptability, and cost of an early ART intervention for HIV-positive truck drivers along a transport corridor across South Africa, Zimbabwe, and Zambia, as part of an enhanced strategy to improve treatment adherence and retention in care. Methods and Analysis. This demonstration study would follow an observational cohort of truck drivers receiving early treatment. Our mixed methods approach includes quantitative, qualitative, and economic analyses. Key ethical and logistical issues are discussed (i.e., choice of drug regimen, recruitment of participants, and monitoring of adherence, behavioural changes, and adverse events). Conclusion. Questions specific to the design of tailored early ART programmes are amenable to operational research approaches but present substantial ethical and logistical challenges. Addressing these in demonstration projects can inform policy decisions regarding strategies to reduce health inequalities in access to HIV prevention and treatment programmes.

Validation of a health literacy screening tool (REALM) in a UK population with coronary heart disease.

BACKGROUND: Health literacy (HL) has been recognized as an important public health issue in other developed countries such as the US. There is currently no HL screening tool valid for use in the UK. This study aimed to validate a US-developed HL screening tool (the Rapid Estimate for Adult Literacy in Medicine; REALM) for use in the UK against the UK's general literacy screening tool (the Basic Skills Agency Initial Assessment Test, BSAIT). METHODS: A cross-sectional survey involving 300 adult patients admitted to hospital for investigation of coronary heart disease were given the REALM and BSAIT tools to complete as well as specific questions considered likely to predict HL. These questions relate to the difficulty in understanding medical information, medical forms or instructions on tablets, frequency of reading books and whether the participant's job involves reading. RESULTS: The REALM was significantly correlated with the BSAIT (r = 0.70; P < 0.001), and significantly related to seven of the eight questions likely to be predictive of HL. CONCLUSIONS: This study has shown that the REALM has face, criterion and construct validity for use as an HL screening tool in the UK, in research and in everyday clinical practice. Further studies are needed to assess the prevalence of low HL in a wider population and to explore the links that may exist between low HL and poor health in the UK.