The benefits and challenges of taxing sugar in a small island state: an interrupted time series analysis.

BACKGROUND: Beverage and food taxes have become a popular 'best buy' public health intervention in the global battle to tackle noncommunicable diseases. Though many countries have introduced taxes, mainly targeting products containing sugar, there is great heterogeneity in tax design. For taxes levied as import tariffs, there is limited evidence of effectiveness in changing the price and sale of taxed products, while the evidence base is stronger for excise taxes levied as a fixed amount per quantity of product. This paper examines the effect of the Bermuda Discretionary Foods Tax, which was based on import tariff changes, on retail prices and sales of sugar-sweetened beverages (SSBs), and on selected fruits and vegetables that benefited from a tariff reduction. METHODS: We used weekly electronic point-of-sale data from a major food retailer in Bermuda. We assessed historical weekly sales and price data using an interrupted time series design on 2,703 unique products between the dates of January 2018 through January 2020, covering 103 weeks. RESULTS: By January 2020, the average price per ounce of SSBs increased by 26.0%, while the price of untaxed beverages (including waters and non-added sugar drinks) remained constant. The increasing price of SSBs was the sole observable structural driver of SSB market share, responsible for a decrease in the market share by nearly eight percentage points by the end of the study period. The subsidy on fruits and vegetables was ineffective in changing prices and sales, due to the relatively small 5% import tax decrease. CONCLUSIONS: The tax was largely passed through to consumers. However, several factors mitigated the impact of the tax on the prices paid for SSBs by consumers, including the specific design of the tax, price promotions and consumer responses. The experience of Bermuda provides important lessons for the planning of similar taxes in the future.

The 'sugar tax' in Bermuda: a mixed methods study of general population and key stakeholder perceptions.

BACKGROUND: Taxes on discretionary foods and sugar-sweetened beverages have emerged as a strategy for health promotion. Between 2018-2019, the Bermuda government introduced a phased tax on imported sugar-sweetened beverages, confectionery, products containing cocoa and pure sugar, and eliminated import duties on select healthy food items. The aim of this study was to conduct an mixed methods evaluation of perceptions of the tax among the general population and key stakeholders. METHODS: We conducted a survey of the general population (N = 400), and semi-structured interviews with key informants (N = 14) from the government, food and beverage, and health sectors to understand awareness, acceptability, and perceived impact of the tax after implementation. Survey data was analysed using thematic analysis, summary statistics, and Chi-squared tests. Key informant interviews were analysed using the framework method. RESULTS: General population respondents had high awareness of the sugar tax (94%) but low awareness of the healthy food subsidy (32%). Most respondents (67%) felt the tax was not an appropriate way to motivate healthier consumption due to beliefs the tax would not be effective (44%), and because of the high price of healthy food (20%). However, nearly half (48%) reported consuming fewer taxed products, primarily for health reasons but also motivated by price increases. Key informants indicated there was high awareness but limited understanding of the tax policy. Informants expressed support for taxation as a health promotion strategy, conditional on policy implementation. The lack of clear price differentiation between taxed and un-taxed products and the absence of accompanying health education were key factors believed to affect the impact of the tax. No informants were aware of use of tax revenues for health purposes and tax revenue was reportedly re-directed to other priorities after implementation. CONCLUSIONS: There was high awareness, but limited acceptability of the Bermuda sugar tax as implemented. Clarity in the tax policy, appropriateness of the tax mechanism, and use of revenue in alignment with the tax aim are critical components for acceptance. The absence of complementary education and health promotion affected acceptance and may limit potential health impacts. The lessons learned in Bermuda can inform similar policies in other settings.

Monitoring progress towards the first UNAIDS 90-90-90 target in key populations living with HIV in Norway.

BACKGROUND: In line with the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 target, Norway aims for at least 90% of people living with HIV (PLHIV) to know their HIV-status. We produced current estimates of the number of PLHIV and undiagnosed population in Norway, overall and for six key subpopulations: Norwegian-born men who have sex with men (MSM), migrant MSM, Norwegian-born heterosexuals, migrant Sub-Saharan Africa (SSA)-born heterosexuals, migrant non-SSA-born heterosexuals and people who inject drugs. METHODS: We used the European Centre for Disease Prevention and Control (ECDC) HIV Modelling Tool on Norwegian HIV surveillance data through 2018 to estimate incidence, time from infection to diagnosis, PLHIV, and the number and proportion undiagnosed. As surveillance data on CD4 count at diagnosis were not collected in Norway, we ran two models; using default model CD4 assumptions, or a proxy for CD4 distribution based on Danish national surveillance data. We also generated alternative overall PLHIV estimates using the Spectrum AIDS Impact Model, to compare with those obtained from the ECDC tool. RESULTS: Estimates of the overall number of PLHIV in 2018 using different modelling approaches aligned at approximately 5000. In both ECDC models, the overall number undiagnosed decreased continuously from 2008. The proportion undiagnosed in 2018 was lower using default model CD4 assumptions (7.1% [95%CI: 5.3-8.9%]), than the Danish CD4 proxy (10.2% [8.3-12.1%]). This difference was driven by results for heterosexual migrants. Estimates for Norwegian-born MSM, migrant MSM and Norwegian-born heterosexuals were similar in both models. In these three subpopulations, incidence in 2018 was < 30 new infections, and the number undiagnosed had decreased in recent years. Norwegian-born MSM had the lowest estimated number of undiagnosed infections (45 [30-75], using default CD4 assumptions) and undiagnosed fraction (3.6% [2.4-5.7%], using default CD4 assumptions) in 2018. CONCLUSIONS: Results allow cautious confidence in concluding that Norway has achieved the first UNAIDS 90-90-90 target, and clearly highlight the success of prevention strategies among MSM. Estimates for subpopulations strongly influenced by migration remain less clear, and future modelling should appropriately account for all-cause mortality and out-migration, and adjust for time of in-migration.

The cost and impact of scaling up pre-exposure prophylaxis for HIV prevention: a systematic review of cost-effectiveness modelling studies.

BACKGROUND: Cost-effectiveness studies inform resource allocation, strategy, and policy development. However, due to their complexity, dependence on assumptions made, and inherent uncertainty, synthesising, and generalising the results can be difficult. We assess cost-effectiveness models evaluating expected health gains and costs of HIV pre-exposure prophylaxis (PrEP) interventions. METHODS AND FINDINGS: We conducted a systematic review comparing epidemiological and economic assumptions of cost-effectiveness studies using various modelling approaches. The following databases were searched (until January 2013): PubMed/Medline, ISI Web of Knowledge, Centre for Reviews and Dissemination databases, EconLIT, and region-specific databases. We included modelling studies reporting both cost and expected impact of a PrEP roll-out. We explored five issues: prioritisation strategies, adherence, behaviour change, toxicity, and resistance. Of 961 studies retrieved, 13 were included. Studies modelled populations (heterosexual couples, men who have sex with men, people who inject drugs) in generalised and concentrated epidemics from Southern Africa (including South Africa), Ukraine, USA, and Peru. PrEP was found to have the potential to be a cost-effective addition to HIV prevention programmes in specific settings. The extent of the impact of PrEP depended upon assumptions made concerning cost, epidemic context, programme coverage, prioritisation strategies, and individual-level adherence. Delivery of PrEP to key populations at highest risk of HIV exposure appears the most cost-effective strategy. Limitations of this review include the partial geographical coverage, our inability to perform a meta-analysis, and the paucity of information available exploring trade-offs between early treatment and PrEP. CONCLUSIONS: Our review identifies the main considerations to address in assessing cost-effectiveness analyses of a PrEP intervention--cost, epidemic context, individual adherence level, PrEP programme coverage, and prioritisation strategy. Cost-effectiveness studies indicating where resources can be applied for greatest impact are essential to guide resource allocation decisions; however, the results of such analyses must be considered within the context of the underlying assumptions made. Please see later in the article for the Editors' Summary.

Understanding the modes of transmission model of new HIV infection and its use in prevention planning.

The modes of transmission model has been widely used to help decision-makers target measures for preventing human immunodeficiency virus (HIV) infection. The model estimates the number of new HIV infections that will be acquired over the ensuing year by individuals in identified risk groups in a given population using data on the size of the groups, the aggregate risk behaviour in each group, the current prevalence of HIV infection among the sexual or injecting drug partners of individuals in each group, and the probability of HIV transmission associated with different risk behaviours. The strength of the model is its simplicity, which enables data from a variety of sources to be synthesized, resulting in better characterization of HIV epidemics in some settings. However, concerns have been raised about the assumptions underlying the model structure, about limitations in the data available for deriving input parameters and about interpretation and communication of the model results. The aim of this review was to improve the use of the model by reassessing its paradigm, structure and data requirements. We identified key questions to be asked when conducting an analysis and when interpreting the model results and make recommendations for strengthening the model's application in the future.

Cost-effectiveness of easy-access, risk-informed oral pre-exposure prophylaxis in HIV epidemics in sub-Saharan Africa: a modelling study.

BACKGROUND: Approaches that allow easy access to pre-exposure prophylaxis (PrEP), such as over-the-counter provision at pharmacies, could facilitate risk-informed PrEP use and lead to lower HIV incidence, but their cost-effectiveness is unknown. We aimed to evaluate conditions under which risk-informed PrEP use is cost-effective. METHODS: We applied a mathematical model of HIV transmission to simulate 3000 setting-scenarios reflecting a range of epidemiological characteristics of communities in sub-Saharan Africa. The prevalence of HIV viral load greater than 1000 copies per mL among all adults (HIV positive and negative) varied from 1·1% to 7·4% (90% range). We hypothesised that if PrEP was made easily available without restriction and with education regarding its use, women and men would use PrEP, with sufficient daily adherence, during so-called seasons of risk (ie, periods in which individuals are at risk of acquiring infection). We refer to this as risk-informed PrEP. For each setting-scenario, we considered the situation in mid-2021 and performed a pairwise comparison of the outcomes of two policies: immediate PrEP scale-up and then continuation for 50 years, and no PrEP. We estimated the relationship between epidemic and programme characteristics and cost-effectiveness of PrEP availability to all during seasons of risk. For our base-case analysis, we assumed a 3-monthly PrEP cost of US$29 (drug $11, HIV test $4, and $14 for additional costs necessary to facilitate education and access), a cost-effectiveness threshold of $500 per disability-adjusted life-year (DALY) averted, an annual discount rate of 3%, and a time horizon of 50 years. In sensitivity analyses, we considered a cost-effectiveness threshold of $100 per DALY averted, a discount rate of 7% per annum, the use of PrEP outside of seasons of risk, and reduced uptake of risk-informed PrEP. FINDINGS: In the context of PrEP scale-up such that 66% (90% range across setting-scenarios 46-81) of HIV-negative people with at least one non-primary condomless sex partner take PrEP in any given period, resulting in 2·6% (0·9-6·0) of all HIV negative adults taking PrEP at any given time, risk-informed PrEP was predicted to reduce HIV incidence by 49% (23-78) over 50 years compared with no PrEP. PrEP was cost-effective in 71% of all setting-scenarios, and cost-effective in 76% of setting-scenarios with prevalence of HIV viral load greater than 1000 copies per mL among all adults higher than 2%. In sensitivity analyses with a $100 per DALY averted cost-effectiveness threshold, a 7% per year discount rate, or with PrEP use that was less well risk-informed than in our base case, PrEP was less likely to be cost-effective, but generally remained cost-effective if the prevalence of HIV viral load greater than 1000 copies per mL among all adults was higher than 3%. In sensitivity analyses based on additional setting-scenarios in which risk-informed PrEP was less extensively used, the HIV incidence reduction was smaller, but the cost-effectiveness of risk-informed PrEP was undiminished. INTERPRETATION: Under the assumption that making PrEP easily accessible for all adults in sub-Saharan Africa in the context of community education leads to risk-informed use, PrEP is likely to be cost-effective in settings with prevalence of HIV viral load greater than 1000 copies per mL among all adults higher than 2%, suggesting the need for implementation of such approaches, with ongoing evaluation. FUNDING: US Agency for International Development, US President's Emergency Plan for AIDS Relief, and Bill & Melinda Gates Foundation.

Updates to Spectrum's case surveillance and vital registration tool for HIV estimates and projections.

INTRODUCTION: The Case Surveillance and Vital Registration (CSAVR) model within Spectrum estimates HIV incidence trends from surveillance data on numbers of new HIV diagnoses and HIV-related deaths. This article describes developments of the CSAVR tool to more flexibly model diagnosis rates over time, estimate incidence patterns by sex and age group and by key population group. METHODS: We modelled HIV diagnosis rate trends as a mixture of three factors, including temporal and opportunistic infection components. The tool was expanded to estimate incidence rate ratios by sex and age for countries with disaggregated reporting of new HIV diagnoses and AIDS deaths, and to account for information on key populations such as men who have sex with men (MSM), males who inject drugs (MWID), female sex workers (FSW) and females who inject drugs (FWID). We used a Bayesian framework to calibrate the tool in 71 high-income or low-HIV burden countries. RESULTS: Across countries, an estimated median 89% (interquartile range [IQR]: 78%-96%) of HIV-positive adults knew their status in 2019. Mean CD4 counts at diagnosis were stable over time, with a median of 456 cells/µl (IQR: 391-508) across countries in 2019. In European countries reporting new HIV diagnoses among key populations, median estimated proportions of males that are MSM and MWID was 1.3% (IQR: 0.9%-2.0%) and 0.56% (IQR: 0.51%-0.64%), respectively. The median estimated proportions of females that are FSW and FWID were 0.36% (IQR: 0.27%-0.45%) and 0.14 (IQR: 0.13%-0.15%), respectively. HIV incidence per 100 person-years increased among MSM, with median estimates reaching 0.43 (IQR: 0.29-1.73) in 2019, but remained stable in MWID, FSW and FWID, at around 0.12 (IQR: 0.04-1.9), 0.09 (IQR: 0.06-0.69) and 0.13% (IQR: 0.08%-0.91%) in 2019, respectively. Knowledge of HIV status among HIV-positive adults gradually increased since the early 1990s to exceed 75% in more than 75% of countries in 2019 among each key population. CONCLUSIONS: CSAVR offers an approach to using routine surveillance and vital registration data to estimate and project trends in both HIV incidence and knowledge of HIV status.

The impact, cost and cost-effectiveness of oral pre-exposure prophylaxis in sub-Saharan Africa: a scoping review of modelling contributions and way forward.

INTRODUCTION: Oral pre-exposure prophylaxis (PrEP) is a new form of HIV prevention being considered for inclusion in national prevention portfolios. Many mathematical modelling studies have been undertaken that speak to the impact, cost and cost-effectiveness of PrEP programmes. We assess the available evidence from mathematical modelling studies to inform programme planning and policy decision making for PrEP and further research directions. METHODS: We conducted a scoping review of the published modelling literature. Articles published in English which modelled oral PrEP in sub-Saharan Africa, or non-specific settings with relevance to generalized HIV epidemic settings, were included. Data were extracted for the strategies of PrEP use modelled, and the impact, cost and cost-effectiveness of PrEP for each strategy. We define an algorithm to assess the quality and relevance of studies included, summarize the available evidence and identify the current gaps in modelling. Recommendations are generated for future modelling applications and data collection. RESULTS AND DISCUSSION: We reviewed 1924 abstracts and included 44 studies spanning 2007 to 2017. Modelling has reported that PrEP can be a cost-effective addition to HIV prevention portfolios for some use cases, but also that it would not be cost-effective to fund PrEP before other prevention interventions are expanded. However, our assessment of the quality of the modelling indicates cost-effectiveness analyses failed to comply with standards of reporting for economic evaluations and the assessment of relevance highlighted that both key parameters and scenarios are now outdated. Current evidence gaps include modelling to inform service development using updated programmatic information and ex post modelling to evaluate and inform efficient deployment of resources in support of PrEP, especially among key populations, using direct evidence of cost, adherence and uptake patterns. CONCLUSIONS: Updated modelling which more appropriately captures PrEP programme delivery, uses current intervention scenarios, and is parameterized with data from demonstration and implementation projects is needed in support of more conclusive findings and actionable recommendations for programmes and policy. Future analyses should address these issues, aligning with countries to support the needs of programme planners and decision makers for models to more directly inform programme planning and policy.

Summarizing the results and methods of the 2019 Joint United Nations Programme on HIV/AIDS HIV estimates.

: UNAIDS and other partners provide support to countries to develop estimates of HIV and related indicators on an annual basis. These estimates are used to monitor epidemic trends, guide program planning and resource allocation, and inform policy decision-making. The collection of articles in this AIDS supplement provide the headline results for the 2019 UNAIDS estimates and describe the new developments in the methods used to produce these estimates.

National responses to global health targets: exploring policy transfer in the context of the UNAIDS '90-90-90' treatment targets in Ghana and Uganda.

Global health organizations frequently set disease-specific targets with the goal of eliciting adoption at the national-level; consideration of the influence of target setting on national policies, programme and health budgets is of benefit to those setting targets and those intended to respond. In 2014, the Joint United Nations Programme on HIV/AIDS set 'ambitious' treatment targets for country adoption: 90% of HIV-positive persons should know their status; 90% of those on treatment; 90% of those achieving viral suppression. Using case studies from Ghana and Uganda, we explore how the target and its associated policy content have been adopted at the national level. That is whether adoption is in rhetoric only or supported by programme, policy or budgetary changes. We review 23 (14 from Ghana, 9 from Uganda) national policy, operational and strategic documents for the HIV response and assess commitments to '90-90-90'. In-person semi-structured interviews were conducted with purposively sampled key informants (17 in Ghana, 20 in Uganda) involved in programme-planning and resource allocation within HIV to gain insight into factors facilitating adoption of 90-90-90. Interviews were transcribed and analysed thematically, inductively and deductively, guided by pre-existing policy theories, including Dolowitz and Marsh's policy transfer framework to describe features of the transfer and the Global Health Advocacy and Policy Project framework to explain observations. Regardless of notable resource constraints, transfer of the 90-90-90 targets was evident beyond rhetoric with substantial shifts in policy and programme activities. In both countries, there was evidence of attempts to minimize resource constraints by seeking programme efficiencies, prioritization of programme activities and devising domestic financing mechanisms; however, significant resource gaps persist. An effective health network, comprised of global and local actors, mediated the adoption and adaptation, facilitating a shift in the HIV programme from 'business as usual' to approaches targeting geographies and populations.

Empirical validation of the UNAIDS Spectrum model for subnational HIV estimates: case-study of children and adults in Manicaland, Zimbabwe.

BACKGROUND: More cost-effective HIV control may be achieved by targeting geographical areas with high infection rates. The AIDS Impact model of Spectrum - used routinely to produce national HIV estimates - could provide the required subnational estimates but is rarely validated with empirical data, even at a national level. DESIGN: The validity of the Spectrum model estimates were compared with empirical estimates. METHODS: Antenatal surveillance and population survey data from a population HIV cohort study in Manicaland, East Zimbabwe, were input into Spectrum 5.441 to create a simulation representative of the cohort population. Model and empirical estimates were compared for key demographic and epidemiological outcomes. Alternative scenarios for data availability were examined and sensitivity analyses were conducted for model assumptions considered important for subnational estimates. RESULTS: Spectrum estimates generally agreed with observed data but HIV incidence estimates were higher than empirical estimates, whereas estimates of early age all-cause adult mortality were lower. Child HIV prevalence estimates matched well with the survey prevalence among children. Estimated paternal orphanhood was lower than empirical estimates. Including observations from earlier in the epidemic did not improve the HIV incidence model fit. Migration had little effect on observed discrepancies - possibly because the model ignores differences in HIV prevalence between migrants and residents. CONCLUSION: The Spectrum model, using subnational surveillance and population data, provided reasonable subnational estimates although some discrepancies were noted. Differences in HIV prevalence between migrants and residents may need to be captured in the model if applied to subnational epidemics.

Embracing different approaches to estimating HIV incidence, prevalence and mortality.

BACKGROUND: Joint United Nations Programme on HIV/AIDS (UNAIDS) and Murray et al. have both produced sets of estimates for worldwide HIV incidence, prevalence and mortality. Understanding differences in these estimates can strengthen the interpretation of each. METHODS: We describe differences in the two sets of estimates. Where possible, we have drawn on additional published data to which estimates can be compared. FINDINGS: UNAIDS estimates that there were 6 million more people living with HIV (PLHIV) in 2013 (35 million) compared with the Murray et al. estimates (29 million). Murray et al. estimate that new infections and AIDS deaths have declined more gradually than does UNAIDS. Just under one third of the difference in PLHIV is in Africa, where Murray et al. have relied more on estimates of adult mortality trends than on data on survival times. Another third of the difference is in North America, Europe, Central Asia and Australasia. Here Murray et al. estimates of new infections are substantially lower than the number of new HIV/AIDS diagnoses reported by countries, whereas published UNAIDS estimate tend to be greater. The remaining differences are in Latin America and Asia where the data upon which the UNAIDS methods currently rely are more sparse, whereas the mortality data leveraged by Murray et al. may be stronger. In this region, however, anomalies appear to exist between the both sets of estimates and other data. INTERPRETATION: Both estimates indicate that approximately 30 million PLHIV and that antiretroviral therapy has driven large reductions in mortality. Both estimates are useful but show instructive discrepancies with additional data sources. We find little evidence to suggest that either set of estimates can be considered systematically more accurate. Further work should seek to build estimates on as wide a base of data as possible.