World Health Organization cardiovascular disease risk charts: revised models to estimate risk in 21 global regions

BACKGROUND: To help adapt cardiovascular disease risk prediction approaches to low-income and middle-income countries, WHO has convened an effort to develop, evaluate, and illustrate revised risk models. Here, we report the derivation, validation, and illustration of the revised WHO cardiovascular disease risk prediction charts that have been adapted to the circumstances of 21 global regions. METHODS: In this model revision initiative, we derived 10-year risk prediction models for fatal and non-fatal cardiovascular disease (ie, myocardial infarction and stroke) using individual participant data from the Emerging Risk Factors Collaboration. Models included information on age, smoking status, systolic blood pressure, history of diabetes, and total cholesterol. For derivation, we included participants aged 40-80 years without a known baseline history of cardiovascular disease, who were followed up until the first myocardial infarction, fatal coronary heart disease, or stroke event. We recalibrated models using age-specific and sex-specific incidences and risk factor values available from 21 global regions. For external validation, we analysed individual participant data from studies distinct from those used in model derivation. We illustrated models by analysing data on a further 123 743 individuals from surveys in 79 countries collected with the WHO STEPwise Approach to Surveillance. FINDINGS: Our risk model derivation involved 376 177 individuals from 85 cohorts, and 19 333 incident cardiovascular events recorded during 10 years of follow-up. The derived risk prediction models discriminated well in external validation cohorts (19 cohorts, 1 096 061 individuals, 25 950 cardiovascular disease events), with Harrell's C indices ranging from 0·685 (95% CI 0·629-0·741) to 0·833 (0·783-0·882). For a given risk factor profile, we found substantial variation across global regions in the estimated 10-year predicted risk. For example, estimated cardiovascular disease risk for a 60-year-old male smoker without diabetes and with systolic blood pressure of 140 mm Hg and total cholesterol of 5 mmol/L ranged from 11% in Andean Latin America to 30% in central Asia. When applied to data from 79 countries (mostly low-income and middle-income countries), the proportion of individuals aged 40-64 years estimated to be at greater than 20% risk ranged from less than 1% in Uganda to more than 16% in Egypt. INTERPRETATION: We have derived, calibrated, and validated new WHO risk prediction models to estimate cardiovascular disease risk in 21 Global Burden of Disease regions. The widespread use of these models could enhance the accuracy, practicability, and sustainability of efforts to reduce the burden of cardiovascular disease worldwide. FUNDING: World Health Organization, British Heart Foundation (BHF), BHF Cambridge Centre for Research Excellence, UK Medical Research Council, and National Institute for Health Research

Melioidosis Vaccines (MeVa): Attitudes to vaccines, melioidosis and clinical trials in key stakeholders in Ubon Ratchathani, Thailand [version 1; peer review: 2 approved]

Background: Melioidosis is a bacterial infection which kills an estimated 89,000 people per year in tropical and sub-tropical regions, chiefly affecting the poorest. Diabetes is the primary risk factor, conferring a 12-fold increase in risk. Despite limited funding compared to other neglected tropical diseases, melioidosis vaccine development has generated several candidates for clinical development. The most promising is CPS-CRM197/Hcp1, which will be the first to enter a phase I clinical trial, taking place in Oxford in 2023/24. As we move closer to the possibility of an effective melioidosis vaccine, it is critical to work in parallel to understand perceptions toward a vaccine among those living where melioidosis rates are high. Reasons for vaccine acceptance versus hesitancy are complex, and include perceived risk of the target disease, concern about side effects, and above all trust in government, scientists, the pharmaceutical industry and other authorities. Methods: We will carry out a qualitative study in Ubon Ratchathani, Thailand, an endemic region for melioidosis, as groundwork for a potential future melioidosis vaccine efficacy study, and in the longer-term vaccine introduction. This study seeks to explore knowledge and attitudes in three main areas; 1) melioidosis disease, 2) vaccines, and 3) participation in clinical vaccine trials. In-depth interviews and focus group discussions will take place in five participant groups of different risks and exposure to melioidosis. Purposive, convenience sampling will be used, also snowball sampling to reach some participant groups. Sample size will be based on participant’s experience, to inform the line of enquiries of study, or until data saturation, expecting 66–90 participants across all groups. Discussion: The findings of this study will be written up and published in an open access journal, and will be valuable to inform future design of clinical trials as well as engagement and communications associated with future vaccine rollout