Imperial College London

DrRanjeetaThomas

Faculty of MedicineSchool of Public Health

Honoray Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 0923ranjeeta.thomas

 
 
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Location

 

LG 33AMedical SchoolSt Mary's Campus

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Summary

 

Publications

Publication Type
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27 results found

Skovdal M, Sorensen O, Muchemwa D, Nyamwanza R, Maswera R, Svendsen M, Nyamukapa C, Thomas R, Gregson Set al., 2023, “It will not be easy to accept”: Parents conflicting attitudes towards pre-exposure prophylaxis for HIV prevention amongst adolescent girls and young women in Zimbabwe, Research in Social and Administrative Pharmacy, Vol: 19, Pages: 266-271, ISSN: 1551-7411

Background:Pre-exposure prophylaxis, or PrEP, is a pill that has been hailed as a ‘game changer’ for HIV prevention, based on the belief it provides adolescent girls and young women (AGYW) with a level of user-control. However, engagement with PrEP is often dependent on societal factors, such as social attitudes towards gender, sexuality, and PrEP. As parents' communication on sexual and reproductive health issues with AGYW are central to HIV prevention, it is critical to explore how parents talk and think about PrEP.Objective:To examine parental attitudes towards PrEP for HIV prevention amongst adolescent girls and young women in eastern Zimbabwe.Method:A qualitative interview study with 14 parents from two districts in Manicaland, eastern Zimbabwe. Interviews were transcribed, translated, and subjected to thematic network analysis. The concept of ‘attitudes’ steered the analytical work.Results:Parents' attitudes towards PrEP are conflictual, multi-layered, and contingent on the context in which they reflect and talk about PrEP. While parents aspired to be supportive of innovative HIV prevention methods and wanted to see girl-children protected from HIV, they struggled to reconcile this positive and accepting attitude towards PrEP with traditional ‘good girl’ notions, which stigmatize pre-marital sex. Although a few parents articulated an acceptance of PrEP use amongst their daughters, for many this was simply not possible. Many parents thus co-produce public gender orders that prevent adolescent girls and young women from engaging with PrEP.Conclusions:While parents’ conflicting attitudes towards PrEP may provide spaces and opportunities for change, harmful gender norms and negative attitudes towards PrEP must be addressed at a community and cultural level. Only then can parents and their children have productive conversations about sexual health.

Journal article

Thomas R, Cirera L, Brew J, Saute F, Sicuri Eet al., 2021, The short-term impact of a malaria elimination initiative in Southern Mozambique: Application of the synthetic control method to routine surveillance data, Health Economics, Vol: 30, Pages: 2168-2184, ISSN: 1057-9230

In public health epidemiology, quasi-experimental methods are widely used to estimate the causal impacts of interventions. In this paper, we demonstrate the contribution the synthetic control method (SCM) can make in evaluating public health interventions, when routine surveillance data are available and the validity of other quasi-experimental approaches may be in question. In our application, we evaluate the short-term effects of a large-scale Mass Drug Administration (MDA) based malaria elimination initiative in Southern Mozambique. We apply the SCM to district level weekly malaria incidence data and compare the observed reduction in age group specific malaria incidence. Between August 2015 and April 2017, a total of 13,322 (78%) cases of malaria were averted relative to the synthetic control. During the peak malaria seasons, the elimination initiative resulted in an 87% reduction in Year 1 (December 2015–April 2016), and 79% reduction in Year 2 (December 2016–April 2017). Comparison with an interrupted time series approach shows the SCM accounts for pre-intervention trends in the data and post-intervention weather events influencing malaria cases. We conclude MDA brought about a drastic reduction in malaria burden and can be a useful addition to existing (or new) vector control strategies and tools in accelerating towards elimination.

Journal article

Thomas R, Probert W, Sauter R, Mwenge L, Singh S, Kanema S, Vanqa N, Harper A, Burger R, Cori A, Pickles M, Bell-Mandla N, Yang B, Bwalya J, Phiri M, Shanaube K, Floyd S, Donnell D, Bock P, Ayles H, Fidler S, Hayes R, Fraser C, Hauck Ket al., 2021, Cost and cost-effectiveness of a universal HIV testing and treatment intervention in Zambia and South Africa: evidence and projections from the HPTN 071 (PopART) trial, The Lancet Global Health, Vol: 9, Pages: e668-e680, ISSN: 2214-109X

BackgroundThe HPTN 071 (PopART) trial showed that a combination HIV prevention package including universal HIV testing and treatment (UTT) reduced population-level incidence of HIV compared with standard care. However, evidence is scarce on the costs and cost-effectiveness of such an intervention.MethodsUsing an individual-based model, we simulated the PopART intervention and standard care with antiretroviral therapy (ART) provided according to national guidelines for the 21 trial communities in Zambia and South Africa (for all individuals aged >14 years), with model parameters and primary cost data collected during the PopART trial and from published sources. Two intervention scenarios were modelled: annual rounds of PopART from 2014 to 2030 (PopART 2014–30; as the UNAIDS Fast-Track target year) and three rounds of PopART throughout the trial intervention period (PopART 2014–17). For each country, we calculated incremental cost-effectiveness ratios (ICERs) as the cost per disability-adjusted life-year (DALY) and cost per HIV infection averted. Cost-effectiveness acceptability curves were used to indicate the probability of PopART being cost-effective compared with standard care at different thresholds of cost per DALY averted. We also assessed budget impact by projecting undiscounted costs of the intervention compared with standard care up to 2030.FindingsDuring 2014–17, the mean cost per person per year of delivering home-based HIV counselling and testing, linkage to care, promotion of ART adherence, and voluntary medical male circumcision via community HIV care providers for the simulated population was US$6·53 (SD 0·29) in Zambia and US$7·93 (0·16) in South Africa. In the PopART 2014–30 scenario, median ICERs for PopART delivered annually until 2030 were $2111 (95% credible interval [CrI] 1827–2462) per HIV infection averted in Zambia and $3248 (2472–3963) per HIV infection averted in South Afric

Journal article

Schafer R, Thomas R, Robertson L, Eaton J, Mushati P, Nyamukapa C, Hauck K, Gregson Set al., 2020, Spillover HIV prevention effects of a cash transfer trial in East Zimbabwe: evidence from a cluster-randomised trial and general-population survey, BMC Public Health, Vol: 20, ISSN: 1471-2458

BackgroundBenefits of cash transfers (CTs) for HIV prevention have been demonstrated largely in purposively designed trials, commonly focusing on young women. It is less clear if CT interventions not designed for HIV prevention can have HIV-specific effects, including adverse effects. The cluster-randomised Manicaland Cash Transfer Trial (2010–11) evaluated effects of CTs on children’s (2–17 years) development in eastern Zimbabwe. We evaluated whether this CT intervention with no HIV-specific objectives had unintended HIV prevention spillover effects (externalities).MethodsData on 2909 individuals (15–54 years) living in trial households were taken from a general-population survey, conducted simultaneously in the same communities as the Manicaland Trial. Average treatment effects (ATEs) of CTs on sexual behaviour (any recent sex, condom use, multiple partners) and secondary outcomes (mental distress, school enrolment, and alcohol/cigarette/drug consumption) were estimated using mixed-effects logistic regressions (random effects for study site and intervention cluster), by sex and age group (15–29; 30–54 years). Outcomes were also evaluated with a larger synthetic comparison group created through propensity score matching.ResultsCTs did not affect sexual debut but reduced having any recent sex (past 30 days) among young males (ATE: − 11.7 percentage points [PP] [95% confidence interval: -26.0PP, 2.61PP]) and females (− 5.68PP [− 15.7PP, 4.34PP]), with similar but less uncertain estimates when compared against the synthetic comparison group (males: -9.68PP [− 13.1PP, − 6.30PP]; females: -8.77PP [− 16.3PP, − 1.23PP]). There were no effects among older individuals. Young (but not older) males receiving CTs reported increased multiple partnerships (8.49PP [− 5.40PP, 22.4PP]; synthetic comparison: 10.3PP (1

Journal article

Schafer R, Thomas R, Rufurwokuda M, Kadzura N, Nyamukapa C, Gregson Set al., 2020, Relationships between changes in HIV risk perception and condom use in east Zimbabwe 2003-2013: Population-based longitudinal analyses, BMC Public Health, Vol: 20, ISSN: 1471-2458

BackgroundPerceiving a personal risk for HIV infection is considered important for engaging in HIV prevention behaviour and often targeted in HIV prevention interventions. However, there is limited evidence for assumed causal relationships between risk perception and prevention behaviour and the degree to which change in behaviour is attributable to change in risk perception is poorly understood. This study examines longitudinal relationships between changes in HIV risk perception and in condom use and the public health importance of changing risk perception.MethodsData on sexually active, HIV-negative adults (15–54 years) were taken from four surveys of a general-population open-cohort study in Manicaland, Zimbabwe (2003–2013). Increasing condom use between surveys was modelled in generalised estimating equations dependent on change in risk perception between surveys. Accounting for changes in other socio-demographic and behavioural factors, regression models examined the bi-directional relationship between risk perception and condom use, testing whether increasing risk perception is associated with increasing condom use and whether increasing condom use is associated with decreasing risk perception. Population attributable fractions (PAFs) were estimated.ResultsOne thousand, nine hundred eighty-eight males and 3715 females participated in ≥2 surveys, contributing 8426 surveys pairs. Increasing risk perception between two surveys was associated with higher odds of increasing condom use (males: adjusted odds ratio [aOR] = 1.39, 95% confidence interval [CI] = 0.85–2.28, PAF = 3.39%; females: aOR = 1.41 [1.06–1.88], PAF = 6.59%), adjusting for changes in other socio-demographic and behavioural factors. Those who decreased risk perception were also more likely to increase condom use (males: aOR = 1.76 [1.12–2.78]; females: aOR = 1.23

Journal article

Thomas R, Skovdal M, Gallizzi M, Schaefer R, Moorhouse L, Nyamukapa C, Maswera R, Mandizvidza P, Hallett T, Gregson Set al., 2020, Improving risk perception and uptake of voluntary medical male circumcision with peer-education sessions and incentives, in Manicaland, East Zimbabwe: study protocol for a pilot randomised trial, Trials, Vol: 21, ISSN: 1745-6215

BackgroundVoluntary medical male circumcision (VMMC) is a key component of combination HIV-prevention programmes. Several high-HIV-prevalence countries in sub-Saharan Africa, including Zimbabwe, are looking to scale up VMMC activities. There is limited evidence on how a combination of social learning from peer education by a role model with different behavioural incentives influences demand for VMMC in such settings.Methods/DesignThis matched-cluster randomised controlled trial with 1740 participants will compare two behavioural incentives against a control with no intervention. In the intervention clusters, participants will participate in an education session delivered by a circumcised young male (“role model”) on the risks of HIV infection and the benefits from medical male circumcision. All participants will receive contributions towards transport costs to access medical male circumcision at participating clinics. Via blocked randomisation, in the intervention clusters participants will be randomly assigned to receive one of two types of incentives – fixed cash payment or lottery payment – both conditional on undergoing surgical VMMC. In two sites, a community-led intervention will also be implemented to address social obstacles and to increase support from peers, families and social structures. Baseline measures of endpoints will be gathered in surveys. Follow-up assessment at 6 months will include self-reported uptake of VMMC triangulated with clinic data.DiscussionThis is the first trial to pilot-test social learning to improve risk perception and self-efficacy and to address the fear of pain associated with VMMC and possible present-biased preferences with front-loaded compensations as well as fixed or lottery-based cash payments. This study will generate important knowledge to inform HIV-prevention policies about the effectiveness of behavioural interventions and incentives, which could be easily scaled-up.Trial registrationThis tria

Journal article

Thomas R, Skovdal M, Galizzi MM, Schaefer R, Moorhouse L, Nyamukapa C, Maswera R, Mandizvidza P, Hallett T, Gregson Set al., 2019, Improving risk perception and uptake of pre-exposure prophylaxis (PrEP) through interactive feedback-based counselling with and without community engagement in young women in Manicaland, East Zimbabwe: study protocol for a pilot randomized trial, Trials, Vol: 20, ISSN: 1745-6215

BackgroundHIV incidence in adolescent girls and young women remains high in sub-Saharan Africa. Progresstowards uptake of HIV prevention methods remains low. Studies of oral PrEP have shown that uptakeand adherence may be low due to low risk perception and ambivalence around using antiretroviralsfor prevention. No evidence exists on whether an interactive intervention aimed at adjusting riskperception and addressing the uncertainty around PrEP will improve uptake. This pilot research trialaims to provide an initial evaluation of the impact of an interactive digital tablet-based counsellingsession, correcting risk perception and addressing ambiguity around availability, usability andeffectiveness of PrEP.Methods/DesignThis is a matched-cluster randomised controlled trial which will compare an interactive tablet-basededucation intervention against a control with no intervention. The study will be implemented in eightsites. In each site, two matched clusters of villages will be created. One cluster will be randomlyallocated to intervention. In two sites a community engagement intervention will also be implementedto address social obstacles and to increase support from peers, families and social structures. 1,200HIV-negative young women 18-24 years, not on PrEP at baseline will be eligible. Baseline measures ofendpoints will be gathered in surveys. Follow-up assessment at six months will include bio-markers ofPrEP uptake and surveys.DiscussionThis will be the first randomized controlled trial to determine whether interactive feedbackcounselling leads to uptake of HIV prevention methods such as PrEP and reduces risky sexualbehaviour. If successful, policymakers could consider such an intervention in school-based educationcampaigns or as post- HIV-testing counselling for young people.Trial RegistrationThis trial has been registered on clinicaltrials.gov on 21/06/2018 (identifier: NCT03565575).https://clinicaltrials.gov/ct2/show/NCT03565575

Journal article

Li Donni P, Thomas R, 2019, Latent class models for multiple ordered categorical health data: Testing violation of the local independence assumption, Empirical Economics, Vol: 59, Pages: 1903-1931, ISSN: 0377-7332

Latent class models are now widely applied in health economics to analyse heterogeneity in multiple outcomes generated by subgroups of individuals who vary in unobservable characteristics, such as genetic information or latent traits. These models rely on the underlying assumption that associations between observed outcomes are due to their relationship to underlying subgroups, captured in these models by conditioning on a set of latent classes. This implies that outcomes are locally independent within a class. Local independence assumption, however, is sometimes violated in practical applications when there is uncaptured unobserved heterogeneity resulting in residual associations between classes. While several approaches have been proposed in the case of binary and continuous outcomes, little attention has been directed to the case of multiple ordered categorical outcome variables often used in health economics. In this paper, we develop an approach to test for the violation of the local independence assumption in the case of multiple ordered categorical outcomes. The approach provides a detailed decomposition of identified residual association by allowing it to vary across latent classes and between levels of the ordered categorical outcomes within a class. We show how this level of decomposition is important in the case of ordered categorical outcomes. We illustrate our approach in the context of health insurance and healthcare utilization in the US Medigap market.

Journal article

Schaefer R, Thomas R, Nyamukapa C, Maswera R, Kadzura N, Gregson Set al., 2019, Accuracy of HIV risk perception in east Zimbabwe 2003-2013, AIDS and Behavior, Vol: 23, Pages: 2199-2209, ISSN: 1090-7165

Risk perception for HIV infection is an important determinant for engaging in HIV prevention behaviour. We investigate the degree to which HIV risk perception is accurate, i.e. corresponds to actual HIV infection risks, in a general-population open-cohort study in Zimbabwe (2003–2013) including 7201 individuals over 31,326 person-years. Risk perception for future infection (no/yes) at the beginning of periods between two surveys was associated with increased risk of HIV infection (Cox regression hazard ratio = 1.38 [1.07–1.79], adjusting for socio-demographic characteristics, sexual behaviour, and partner behaviour). The association was stronger among older people (25+ years). This suggests that HIV risk perception can be accurate but the higher HIV incidence (1.27 per 100 person-years) illustrates that individuals may face barriers to HIV prevention behaviour even when they perceive their risks. Gaps in risk perception are underlined by the high incidence among those not perceiving a risk (0.96%), low risk perception even among those reporting potentially risky sexual behaviour, and, particularly, lack of accuracy of risk perception among young people. Innovative interventions are needed to improve accuracy of risk perception but barriers to HIV prevention behaviours need to be addressed too, which may relate to the partner, community, or structural factors.

Journal article

Moorhouse L, Schaefer R, Thomas R, Nyamukapa C, Skovdal M, Hallett T, Gregson Set al., 2019, Application of the HIV prevention cascade to identify, develop,and evaluate interventions to improve use of prevention methods:Examples from a study in east Zimbabwe, Journal of the International AIDS Society, Vol: 22, Pages: 86-92, ISSN: 1758-2652

Introduction: The HIV prevention cascade could be used in developing interventions to strengthen implementation of efficacious HIV prevention methods but its practical utility needs to be demonstrated. We propose a standardised approach to using the cascade to guide identification and evaluation of interventions and demonstrate its feasibility through a project to develop interventions to improve use of HIV prevention methods by adolescent girls and young women (AGYW) and potential male partners in east Zimbabwe.Discussion: We propose a six-step approach to using a published generic HIV prevention cascade formulation to develop interventions to increase motivation to use, access to and effective use of an HIV prevention method. The six steps are: (1) measure the HIV prevention cascade for the chosen population and method; (2) identify gaps in the cascade; (3) identify explanatory factors (barriers) contributing to observed gaps; (4) review literature to identify relevant theoretical frameworks and interventions; (5) tailor interventions to the local context; and (6) implement and evaluate the interventions using the cascade steps and explanatory factors as outcome indicators in the evaluation design. In the Zimbabwe example, steps 1-5 aided development of four interventions to overcome barriers to effective use of PrEP in AGYW (15-24 years) and VMMC in male partners (15-29). For young men, prevention cascade analyses identified gaps in motivation and access (due to transport costs/lost income) as barriers to VMMC uptake, so an intervention was designed including financial incentives and an education session. For AGYW, gaps in motivation (particularly lack of risk perception) and access were identified as barriers to PrEP uptake: an interactive counselling game was developed addressing these barriers. A text messaging intervention was developed to improve adherence to PrEP among AGYW, addressing reasons underlying lack of effective PrEP use through improving the capa

Journal article

Thomas R, Friebel R, Barker K, Mwenge L, Kanema S, Vanqa N, Harper A, Bell-Mandla N, Smith P, Floyd S, Bock P, Ayles H, Fidler S, Hayes R, Hauck Ket al., 2019, Work and home productivity of people living with HIV in Zambia and South Africa, AIDS, Vol: 33, Pages: 1063-1071, ISSN: 0269-9370

Objective: To compare number of days lost to illness or accessing healthcare for HIV-positive and HIV-negative individuals working in the informal and formal sectors in South Africa and Zambia.Design: As part of the HPTN 071 (PopART) study, data on adults aged 18–44 years were gathered between in cross-sectional surveys of random general population samples in 21 communities in Zambia and South Africa. Data on the number of productive days lost in the last 3 months, laboratory-confirmed HIV status, labour force status, age, ethnicity, education, and recreational drug use was collected.Methods: Differences in productive days lost between HIV-negative and HIV-positive individuals (“excess productive days lost”) were estimated with negative binomial models, and results disaggregated for HIV-positive individuals after various durations on Anti-retroviral treatment (ART).Results: From samples of 19,330 respondents in Zambia and 18,004 respondents in South Africa, HIV-positive individuals lost more productive days to illness than HIV-negative individuals in both countries. HIV-positive individuals in Zambia lost 0.74 excess productive days (95%CI: 0.48–1.01; p < 0.001) to illness over a three-month period. HIV-positive in South Africa lost 0.13 excess days (95%CI: 0.04–0.23; p = 0.007). In Zambia, those on ART for less than one year lost most days, and those not on ART lost fewest days. In South Africa, results disaggregated by treatment duration were not statistically significant.Conclusions: There is a loss of work and home productivity associated with HIV, but it is lower than existing estimates for HIV-positive formal sector workers. The findings support policy makers in building an accurate investment case for HIV interventions.

Journal article

Hauck K, Morton A, Chalkidou K, Chi Y-L, Culyer A, Levin C, Meacock R, Over M, Thomas R, Vassall A, Verguet S, Smith Pet al., 2019, How can we evaluate the cost-effectiveness of health system strengthening? A typology and illustrations, Social Science and Medicine, Vol: 220, Pages: 141-149, ISSN: 0277-9536

Health interventions often depend on a complex system of human and capital infrastructure that is shared with other interventions, in the form of service delivery platforms, such as healthcare facilities, hospitals, or community services. Most forms of health system strengthening seek to improve the efficiency or effectiveness of such delivery platforms. This paper presents a typology of ways in which health system strengthening can improve the economic efficiency of health services. Three types of health system strengthening are identified and modelled: (1) investment in the efficiency of an existing shared platform that generates positive benefits across a range of existing interventions; (2) relaxing a capacity constraint of an existing shared platform that inhibits the optimization of existing interventions; (3) providing an entirely new shared platform that supports a number of existing or new interventions. Theoretical models are illustrated with examples, and illustrate the importance of considering the portfolio of interventions using a platform, and not just piecemeal individual analysis of those interventions. They show how it is possible to extend principles of conventional cost-effectiveness analysis to identify an optimal balance between investing in health system strengthening and expenditure on specific interventions. The models developed in this paper provide a conceptual framework for evaluating the cost-effectiveness of investments in strengthening healthcare systems and, more broadly, shed light on the role that platforms play in promoting the cost-effectiveness of different interventions.

Journal article

Thomas R, Burger R, Hauck K, 2018, Richer, wiser and in better health? The socioeconomic gradient inhypertension prevalence, unawareness and control in South Africa, Social Science and Medicine, Vol: 217, Pages: 18-30, ISSN: 0277-9536

The socioeconomic gradient in chronic conditions is clear in the poorest and wealthiest of countries, but extant evidence on this relationship in low- and middle-income countries is inconclusive. We use data gathered between 2008-2012 from a nationally representative sample of over 10,000 South African adults, and objective health measures to analyse the differential effects of education, income and other factors on the prevalence of hypertension, individuals' awareness and control of hypertensive status. Prevalence of hypertension is high at 38% amongwomen and 34% among men. 59% of hypertensive individuals are unaware of their status. We and prevalence and unawareness of hypertension are a public health concern across all incomegroups in South Africa. Higher income is however associated with effective control amongst men. Completing secondary education is associated with 7 mmHg lower blood pressure only in a small sub-group of women but is associated with 22 percentage point higher likelihoodof effective hypertension control amongst women. We conclude that poorer and less educated individuals are particularly at high risk of cardiovascular disease in South Africa.

Journal article

Morton A, Arulselvan A, Thomas RA, 2018, Allocation Rules for Global Donors., Journal of Health Economics, Vol: 58, Pages: 67-75, ISSN: 0167-6296

In recent years, donors such as the Bill and Melinda Gates Foundation have made an enormous contribution to the reduction of the global burden of disease. It has been argued that such donors should prioritise interventions based on their cost-effectiveness, that is to say, the ratio of costs to benefits. Against this, we argue that the donor should fund not the most cost-effective interventions, but rather interventions which are just cost-ineffective for the country, thus encouraging the country to contribute its own domestic resources to the fight against disease. We demonstrate that our proposed algorithm can be justified within the context of a model of the problem as a leader-follower game, in which a donor chooses to subsidise interventions which are implemented by a country. We argue that the decision rule we propose provides a basis for the allocation of aid money which is efficient, fair and sustainable.

Journal article

Thomas RA, Burger R, Harper A, Kanema S, Mwenge L, Vanqa N, Bell-Mandla N, Smith P, Floyd S, Bock P, Ayles H, Beyers N, Donnell D, Fidler S, Hayes R, Hauck Ket al., 2017, Differences in health-related quality of life between HIV-positive and HIV-negative people in Zambia and South Africa: a cross-sectional baseline survey of the HPTN 071 (PopART) trial, The Lancet Global Health, Vol: 5, Pages: e1133-e1141, ISSN: 2214-109X

BackgroundThe life expectancy of HIV-positive individuals receiving antiretroviral therapy (ART) is approaching that of HIV-negative people. However, little is known about how these populations compare in terms of health-related quality of life (HRQoL). We aimed to compare HRQoL between HIV-positive and HIV-negative people in Zambia and South Africa.MethodsAs part of the HPTN 071 (PopART) study, data from adults aged 18–44 years were gathered between Nov 28, 2013, and March 31, 2015, in large cross-sectional surveys of random samples of the general population in 21 communities in Zambia and South Africa. HRQoL data were collected with a standardised generic measure of health across five domains. We used β-distributed multivariable models to analyse differences in HRQoL scores between HIV-negative and HIV-positive individuals who were unaware of their status; aware, but not in HIV care; in HIV care, but who had not initiated ART; on ART for less than 5 years; and on ART for 5 years or more. We included controls for sociodemographic variables, herpes simplex virus type-2 status, and recreational drug use.FindingsWe obtained data for 19 750 respondents in Zambia and 18 941 respondents in South Africa. Laboratory-confirmed HIV status was available for 19 330 respondents in Zambia and 18 004 respondents in South Africa; 4128 (21%) of these 19 330 respondents in Zambia and 4012 (22%) of 18 004 respondents in South Africa had laboratory-confirmed HIV. We obtained complete HRQoL information for 19 637 respondents in Zambia and 18 429 respondents in South Africa. HRQoL scores did not differ significantly between individuals who had initiated ART more than 5 years previously and HIV-negative individuals, neither in Zambia (change in mean score −0·002, 95% CI −0·01 to 0·001; p=0·219) nor in South Africa (0·000, −0·002 to 0·003; p=0·939). However, scores did differ between HIV-positive individu

Journal article

Cundale K, Thomas R, Malaya JK, Havens D, Mortimer K, Conteh Let al., 2017, A health intervention or a kitchen appliance? Household costs and benefits of a cleaner burning biomass-fuelled cookstove in Malawi, SOCIAL SCIENCE & MEDICINE, Vol: 183, Pages: 1-10, ISSN: 0277-9536

Pneumonia is the leading cause of mortality for children under five years in sub-Saharan Africa. Household air pollution has been found to increase risk of pneumonia, especially due to exposure from dirty burning biomass fuels. It has been suggested that advanced stoves, which burn fuel more efficiently and reduce smoke emissions, may help to reduce household air pollution in poor, rural settings.This qualitative study aims to provide an insight into the household costs and perceived benefits from use of the stove in Malawi. It was conducted alongside The Cooking and Pneumonia Study (CAPS), the largest village cluster-level randomised controlled trial of an advanced combustion cookstove intervention to prevent pneumonia in children under five to date. In 2015, using 100 semi-structured interviews this study assessed household time use and perceptions of the stove from both control and intervention participants taking part in the CAPS trial in Chilumba. Household direct and indirect costs associated with the intervention were calculated.Users overwhelming liked using the stove. The main reported benefits were reduced cooking times and reduced fuel consumption. In most interviews, the health benefits were not initially identified as advantages of the stove, although when prompted, respondents stated that reduced smoke emissions contributed to a reduction in respiratory symptoms. The cost of the stove was much higher than most respondents said they would be willing to pay.The stoves were not primarily seen as health products. Perceptions of limited impact on health was subsequently supported by the CAPS trial data which showed no significant effect on pneumonia. While the findings are encouraging from the perspective of acceptability, without innovative financing mechanisms, general uptake and sustained use of the stove may not be possible in this setting. The findings also raise the question of whether the stoves should be marketed and championed as ‘health inte

Journal article

Hauck KD, Thomas R, Smith P, 2017, Beyond Cost Effectiveness: Health Systems Constraints to Delivery of a Health Benefits Package, What's in What's out: Designing Benefits for Universal Health Coverage, Editors: Glassman, Giedion, Smith, Publisher: Center for Global Development, Pages: 201-213

Book chapter

Thomas RA, Chalkidou K, 2016, Cost–effectiveness analysis, Health System Efficiency How to Make Measurement Matter for Policy and Management, Editors: Smith, Cylus, Papanicolas, Publisher: European Observatory on Health Systems and Policies, ISBN: 9789289050418

In this book the authors explore the state of the art on efficiency measurement in health systems and international experts offer insights into the pitfalls and potential associated with various measurement techniques.

Book chapter

Heffernan A, Barber E, Thomas R, Fraser C, Pickles M, Cori Aet al., 2016, Impact and Cost-Effectiveness of Point-Of-Care CD4 Testing on the HIV Epidemic in South Africa., PLOS One, Vol: 11, ISSN: 1932-6203

Rapid diagnostic tools have been shown to improve linkage of patients to care. In the context of infectious diseases, assessing the impact and cost-effectiveness of such tools at the population level, accounting for both direct and indirect effects, is key to informing adoption of these tools. Point-of-care (POC) CD4 testing has been shown to be highly effective in increasing the proportion of HIV positive patients who initiate ART. We assess the impact and cost-effectiveness of introducing POC CD4 testing at the population level in South Africa in a range of care contexts, using a dynamic compartmental model of HIV transmission, calibrated to the South African HIV epidemic. We performed a meta-analysis to quantify the differences between POC and laboratory CD4 testing on the proportion linking to care following CD4 testing. Cumulative infections averted and incremental cost-effectiveness ratios (ICERs) were estimated over one and three years. We estimated that POC CD4 testing introduced in the current South African care context can prevent 1.7% (95% CI: 0.4% - 4.3%) of new HIV infections over 1 year. In that context, POC CD4 testing was cost-effective 99.8% of the time after 1 year with a median estimated ICER of US$4,468/DALY averted. In healthcare contexts with expanded HIV testing and improved retention in care, POC CD4 testing only became cost-effective after 3 years. The results were similar when, in addition, ART was offered irrespective of CD4 count, and CD4 testing was used for clinical assessment. Our findings suggest that even if ART is expanded to all HIV positive individuals and HIV testing efforts are increased in the near future, POC CD4 testing is a cost-effective tool, even within a short time horizon. Our study also illustrates the importance of evaluating the potential impact of such diagnostic technologies at the population level, so that indirect benefits and costs can be incorporated into estimations of cost-effectiveness.

Journal article

Thomas RA, Morton A, Smith P, 2016, Decision rules for allocation of finances to health systems strengthening, Journal of Health Economics, Vol: 49, Pages: 97-108, ISSN: 0167-6296

A key dilemma in global health is how to allocate funds between disease-specific “vertical projects” on the one hand and “horizontal programmes” which aim to strengthen the entire health system on the other. While economic evaluation provides a way of approaching the prioritisation of vertical projects, it provides less guidance on how to prioritise between horizontal and vertical spending. We approach this problem by formulating a mathematical program which captures the complementary benefits of funding both vertical projects and horizontal programmes. We show that our solution to this math program has an appealing intuitive structure. We illustrate our model by computationally solving two specialised versions of this problem, with illustrations based on the problem of allocating funding for infectious diseases in sub-Saharan Africa. We conclude by reflecting on how such a model may be developed in the future and used to guide empirical data collection and theory development.

Journal article

Gregson S, Fenton R, Nyamukapa C, Robertson L, Mushati P, Thomas R, Eaton Jet al., 2016, Wealth Differentials in the Impact of Conditional and Unconditional Cash Transfers on Education: Findings from a Community-Randomised Controlled Trial in Zimbabwe, Psychology, Health & Medicine, Vol: 21, Pages: 909-917, ISSN: 1354-8506

We investigated (1) how household wealth affected the relationshipbetween conditional cash transfers (CCT) and unconditional cashtransfers (UCT) and school attendance, (2) whether CCT and UCTaffected educational outcomes (repeating a year of school), (3) ifbaseline school attendance and transfer conditions affected howmuch of the transfers participants spent on education and (4) if CCTor UCT reduced child labour in recipient households. Data wereanalysed from a cluster-randomized controlled trial of CCT and UCTin 4043 households from 2009 to 2010. Recipient households received$18 dollars per month plus $4 per child. CCT were conditioned onabove 80% school attendance, a full vaccination record and a birthcertificate. In the poorest quintile, the odds ratio of above 80% schoolattendance at follow-up for those with below 80% school attendanceat baseline was 1.06 (p = .67) for UCT vs. CCT. UCT recipients reportedspending slightly more (46.1% (45.4–46.7)) of the transfer on schoolexpenses than did CCT recipients (44.8% (44.1–45.5)). Amongstthose with baseline school attendance of below 80%, there was nostatistically significant difference between CCT and UCT participantsin the proportion of the transfer spent on school expenses (p = .63).Amongst those with above 80% baseline school attendance, CCTparticipants spent 3.5% less (p = .001) on school expenses than UCTparticipants. UCT participants were no less likely than those in thecontrol group to repeat a grade of school. CCT participants had .69(.60–.79) lower odds vs. control of repeating the previous schoolgrade. Children in CCT recipient households spent an average of .31fewer hours in paid work than those in the control group (p < .001)and children in the UCT arm spent an average of .15 fewer hours inpaid work each week than those in the control arm (p = .06).

Journal article

Hauck KD, Thomas R, Smith PC, 2016, Departures from cost-effectiveness recommendations: The impact of health system constraints on priority setting, Health Systems & Reform, Vol: 2, Pages: 61-70, ISSN: 2328-8604

The methods and application of cost-effectiveness analysis have reached an advanced stage of development. Many decision makers consider cost-effectiveness analysis to be a valid and feasible approach towards setting health priorities, and it has been extensively applied in evaluating interventions and developing evidence based clinical guidelines. However, the recommendations arising from cost-effectiveness analysis are often not implemented as intended. A fundamental reason for the failure to implement is that CEA assumes a single constraint, in the form of the budget constraint, whilst in reality decision-makers may be faced with numerous other constraints. The objective of this paper is to develop a typology of constraints that may act as barriers to implementation of cost-effectiveness recommendations. Six categories of constraints are considered: the design of the health system; costs of implementing change; system interactions between interventions; uncertainty in estimates of costs and benefits; weak governance; and political constraints. Where possible -and if applicable- for each class of constraint, the paper discusses ways in which these constraints can be taken into account by a decision maker wishing to pursue the principles of cost-effectiveness.

Journal article

Anand P, Gray A, Liberini F, Roope L, Smith R, Thomas Ret al., 2015, Wellbeing over 50, JOURNAL OF THE ECONOMICS OF AGEING, Vol: 6, Pages: 68-78, ISSN: 2212-828X

Journal article

Thomas RA, 2012, Conditional Cash Transfers to Improve Education and Health: An ex ante evaluation of Red de Protección Social, Nicaragua, Health Economics, Pages: 1136-1154, ISSN: 1099-1050

Journal article

Jones AM, Squire L, Thomas RA, 2010, Evaluating innovative health programs, Health Economics, Vol: 19(S1), Pages: 1-4, ISSN: 1057-9230

Identifying innovative interventi ons that meet critical health policy needs in local settings is likely to benefit from local knowledge. The Global Development Network’s (GDN) project ‘Evaluating Innovative Health Program s’ (EIHP) project is built on the ability of local researchers to identify such solutions. It evaluates the impact of 19 programs from across developing and transition countries that focus on the health-related Mill ennium Development Goals (MDGs) of reducing child and maternal mortality, and halting and reversing the trend of communicable diseases such as HIV/AIDS, malaria, and other diseases (United Nations, 2008). Local researchers are often be st placed to identify innovativesolutions to the problem faced in their countries. That said, identifying the impact of these interventions requires rigorous evaluations. The credibility of the findings depends on the quality of the evaluations.The research skills required to carry out these evaluations are not always available in these countries. Building long-term evaluation capacity is a key component of this project and has advantages both in terms of increasing the quality of the evaluations carried out under this project and also in encouraging future evaluations. To promote capacity building, a panel of international experts in impact evaluation was identified to act as mentors. Each research team was paired with a mentor through the duration of the evaluation. The panel of experts was drawn from leading academic institutions. The mentors provided active guidance in the design of the evaluation and the methods used. They facilitated transferof knowledge as well as ensuring evaluations met rigorous methodological standards. African and Asian policymakers from health and related ministries and practitioners from NGOs were involved in the project from its inception. A policymakers/practitioners panel, comprising African and Asian policymakers and practitioners, is a key element of the

Journal article

Thomas R, Jones A, Squire L, 2010, Methods for Evaluating Innovative Health Programs: a multi-country study, Journal of Development Effectiveness, Vol: 2, Pages: 504-520

Designed as a global research initiative, the Evaluating Innovative Health Programs project aims at adding to the evidence base of health interventions that have the potential to improve health outcomes in Africa and Asia. The project focuses on rigorous, quantitative evaluations of innovative local initiatives that address the Millennium Development Goals for health: reductions in child and maternal mortality and communicable diseases. This overview brings together the outcomes and lessons from the project for evaluation methods. It draws together the methodological implications of carrying out impact evaluations under very different settings and emphasises the need to build evaluations into project designs.

Journal article

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