Laboratory-based and office-based risk scores and charts to predict 10-year risk of cardiovascular disease in 182 countries: a pooled analysis of prospective cohorts and health surveys.

BACKGROUND: Worldwide implementation of risk-based cardiovascular disease (CVD) prevention requires risk prediction tools that are contemporarily recalibrated for the target country and can be used where laboratory measurements are unavailable. We present two cardiovascular risk scores, with and without laboratory-based measurements, and the corresponding risk charts for 182 countries to predict 10-year risk of fatal and non-fatal CVD in adults aged 40-74 years. METHODS: Based on our previous laboratory-based prediction model (Globorisk), we used data from eight prospective studies to estimate coefficients of the risk equations using proportional hazard regressions. The laboratory-based risk score included age, sex, smoking, blood pressure, diabetes, and total cholesterol; in the non-laboratory (office-based) risk score, we replaced diabetes and total cholesterol with BMI. We recalibrated risk scores for each sex and age group in each country using country-specific mean risk factor levels and CVD rates. We used recalibrated risk scores and data from national surveys (using data from adults aged 40-64 years) to estimate the proportion of the population at different levels of CVD risk for ten countries from different world regions as examples of the information the risk scores provide; we applied a risk threshold for high risk of at least 10% for high-income countries (HICs) and at least 20% for low-income and middle-income countries (LMICs) on the basis of national and international guidelines for CVD prevention. We estimated the proportion of men and women who were similarly categorised as high risk or low risk by the two risk scores. FINDINGS: Predicted risks for the same risk factor profile were generally lower in HICs than in LMICs, with the highest risks in countries in central and southeast Asia and eastern Europe, including China and Russia. In HICs, the proportion of people aged 40-64 years at high risk of CVD ranged from 1% for South Korean women to 42% for Czech men (using a ≥10% risk threshold), and in low-income countries ranged from 2% in Uganda (men and women) to 13% in Iranian men (using a ≥20% risk threshold). More than 80% of adults were similarly classified as low or high risk by the laboratory-based and office-based risk scores. However, the office-based model substantially underestimated the risk among patients with diabetes. INTERPRETATION: Our risk charts provide risk assessment tools that are recalibrated for each country and make the estimation of CVD risk possible without using laboratory-based measurements. FUNDING: National Institutes of Health.

A novel risk score to predict cardiovascular disease risk in national populations (Globorisk): a pooled analysis of prospective cohorts and health examination surveys.

BACKGROUND: Treatment of cardiovascular risk factors based on disease risk depends on valid risk prediction equations. We aimed to develop, and apply in example countries, a risk prediction equation for cardiovascular disease (consisting here of coronary heart disease and stroke) that can be recalibrated and updated for application in different countries with routinely available information. METHODS: We used data from eight prospective cohort studies to estimate coefficients of the risk equation with proportional hazard regressions. The risk prediction equation included smoking, blood pressure, diabetes, and total cholesterol, and allowed the effects of sex and age on cardiovascular disease to vary between cohorts or countries. We developed risk equations for fatal cardiovascular disease and for fatal plus non-fatal cardiovascular disease. We validated the risk equations internally and also using data from three cohorts that were not used to create the equations. We then used the risk prediction equation and data from recent (2006 or later) national health surveys to estimate the proportion of the population at different levels of cardiovascular disease risk in 11 countries from different world regions (China, Czech Republic, Denmark, England, Iran, Japan, Malawi, Mexico, South Korea, Spain, and USA). FINDINGS: The risk score discriminated well in internal and external validations, with C statistics generally 70% or more. At any age and risk factor level, the estimated 10 year fatal cardiovascular disease risk varied substantially between countries. The prevalence of people at high risk of fatal cardiovascular disease was lowest in South Korea, Spain, and Denmark, where only 5-10% of men and women had more than a 10% risk, and 62-77% of men and 79-82% of women had less than a 3% risk. Conversely, the proportion of people at high risk of fatal cardiovascular disease was largest in China and Mexico. In China, 33% of men and 28% of women had a 10-year risk of fatal cardiovascular disease of 10% or more, whereas in Mexico, the prevalence of this high risk was 16% for men and 11% for women. The prevalence of less than a 3% risk was 37% for men and 42% for women in China, and 55% for men and 69% for women in Mexico. INTERPRETATION: We developed a cardiovascular disease risk equation that can be recalibrated for application in different countries with routinely available information. The estimated percentage of people at high risk of fatal cardiovascular disease was higher in low-income and middle-income countries than in high-income countries. FUNDING: US National Institutes of Health, UK Medical Research Council, Wellcome Trust.

Anthropometric measurements and prevalence of underweight, overweight and obesity in adult Malawians: nationwide population based NCD STEPS survey.

INTRODUCTION: Overweight and obesity are significant causes of increased morbidity and premature mortality from non-communicable diseases, particularly in sub-Saharan Africa, although local high quality population-based data to inform policies and strategies are lacking. METHODS: Using the WHO STEPwise approach to chronic disease risk factor surveillance, population-based nationwide survey was conducted on participants aged 25-64 years in Malawi. A multi-stage cluster sample design and weighting were used to produce a national representative data for that age range. RESULTS: A total of 4845 participants (65.7% females, 87.6% from rural areas) had complete anthropometric data and included in this analysis. Overall (both sexes) population-based mean body weight, height, systolic blood pressure, diastolic blood pressure, blood glucose and cholesterol were estimated at 58.7 kg, 159.9 cm, 133.4 mmHg, 79.5 mmHg, 4.3 mmol/L, 4.4 mmol/L respectively. Prevalence of underweight, overweight, obesity, overweight and/ or obesity and central adiposity were 6.5%, 17.3%, 4.6%, 21.9% and 28.8% respectively. Overweight, obesity, overweight and/ or obesity and central adiposity were more frequent in females than males (20.7% vs 14.1%, 7.4% vs 2.0%, 28.1% vs 16.1% and 52.8% vs 5.6%), in urban than rural areas (23.2% vs 16.6%, 12.0% vs 3.7%, 35.2% vs 20.2%) respectively. CONCLUSION: This study demonstrated that overweight and/ or obesity is the major public health problem affecting at least one in five adults in Malawi. The problem is more frequent in females than males and urban than rural. Implementation of primary health care approaches such as WHO package for essential non-communicable diseases could reduce the problem.

Inequalities in non-communicable diseases and effective responses.

In most countries, people who have a low socioeconomic status and those who live in poor or marginalised communities have a higher risk of dying from non-communicable diseases (NCDs) than do more advantaged groups and communities. Smoking rates, blood pressure, and several other NCD risk factors are often higher in groups with low socioeconomic status than in those with high socioeconomic status; the social gradient also depends on the country's stage of economic development, cultural factors, and social and health policies. Social inequalities in risk factors account for more than half of inequalities in major NCDs, especially for cardiovascular diseases and lung cancer. People in low-income countries and those with low socioeconomic status also have worse access to health care for timely diagnosis and treatment of NCDs than do those in high-income countries or those with higher socioeconomic status. Reduction of NCDs in disadvantaged groups is necessary to achieve substantial decreases in the total NCD burden, making them mutually reinforcing priorities. Effective actions to reduce NCD inequalities include equitable early childhood development programmes and education; removal of barriers to secure employment in disadvantaged groups; comprehensive strategies for tobacco and alcohol control and for dietary salt reduction that target low socioeconomic status groups; universal, financially and physically accessible, high-quality primary care for delivery of preventive interventions and for early detection and treatment of NCDs; and universal insurance and other mechanisms to remove financial barriers to health care.

Burden of leprosy in Malawi: community camp-based cross-sectional study.

BACKGROUND: Although leprosy was eliminated globally in 2000, the disease continues to be the significant cause of peripheral neuropathy, disability and disfigurement in some developing countries. However, recent population-based prevalence data are lacking to inform evidence-based renewed commitment for the final push for leprosy elimination at national and sub-national levels. METHODS: Community camp-based cross-sectional descriptive study was conducted in four selected districts. World Health Organisation guidelines and tools for leprosy elimination monitoring were used to evaluate the Malawi National Leprosy Programme. RESULTS: A total of 6,338 people (60% females, 35% children aged less than 15 years) were examined for leprosy and other skin diseases. Prevalence of skin diseases was 18%, the commonest being fungal (9%), eczema/dermatitis (3%) and leprosy (1%). Of the fungal skin conditions, pityriasis versicolor and Tinea capatis were the commonest (22% and 21% respectively) then Tinea corporis (9%), Tinea cruris (6%) and Tinea pedis (2%). A total of 66 leprosy cases were detected out of 6,338 people screened giving a prevalence of 104.1 per 10,000 population (range by district 67.1 to 194.1). Of the leprosy cases, 37 were new, 6 were defaulters and 23 were on treatment, 30 were females and 9 were children aged less than 15 years old. Of the 37 new leprosy cases, 9 (24.3%) were children, 25 (67.6%) had 1-5 leprosy lesions and 8 (21.6%) had grade 2 disability. The most frequent location of leprosy lesions was the head and neck (24.1%), arms (24.1%), chest (17.2%), legs (13.8%), back (13.8%) and abdomen (7.0%). Between 2006 and 2011, trends of leprosy prevalence and detection increased, prevalence/detection ratios were over 1 and cure rates by cohort analysis of 2009 multibacillary and 2010 paucibacillary cases were 33% and 63% respectively far below the expected 80% although the national prevalence remained at less than 1 case per 10,000 population. CONCLUSION: Leprosy was still an important public health problem in Malawi. Improving knowledge and skills of health workers, registration and recording of data, contact tracing, decentralisation and integration of treatment to health centres and introduction of leprosy awareness days and community-based surveillance could help to improve early detection, treatment, case holding and prevention of disabilities.

The burden of hypertension and its risk factors in Malawi: nationwide population-based STEPS survey.

Hypertension is the most common cause of cardiovascular diseases, accounting for at least half of haemorrhagic and ischaemic strokes, heart failure and renal failure in sub-Saharan Africa. However, population-based data to inform policies are scarce. Using the WHO STEPwise approach to chronic disease risk factor surveillance, a population-based nationwide survey was conducted on participants aged 25-64 years in Malawi. Detailed findings on the burden of hypertension are presented in this paper. Blood pressure (BP) was measured in 3727 participants. The age-standardised prevalence of hypertension (BP ≥140/90 mmHg) was 33.2% (95% CI 30.9-35.6%). Hypertension was more frequent in males than females (36.9% vs 29.9%), alcohol drinkers than non-drinkers (40.9% vs 31.6%), overweight than non-overweight (41.5% vs 30.7%) and increased with increasing age (21.4% in 25-34 years old vs 59.2% in 55-64 years old). Three-quarters of the participants said they never had their BP measured before and 94.9% of those with hypertension said they were not aware that they had such a medical problem. High prevalence of hypertension and its risk factors calls for the implementation of primary healthcare approaches such as the WHO package for essential non-communicable diseases to promote healthy lifestyles, early detection, treatment and control.

The burden of selected chronic non-communicable diseases and their risk factors in Malawi: nationwide STEPS survey.

BACKGROUND: Chronic non-communicable diseases (NCDs) are becoming significant causes of morbidity and mortality, particularly in sub-Saharan African countries, although local, high-quality data to inform evidence-based policies are lacking. OBJECTIVES: To determine the magnitude of NCDs and their risk factors in Malawi. METHODS: Using the WHO STEPwise approach to chronic disease risk factor surveillance, a population-based, nationwide cross-sectional survey was conducted between July and September 2009 on participants aged 25-64 years. Socio-demographic and behaviour risk factors were collected in Step 1. Physical anthropometric measurements and blood pressure were documented in Step 2. Blood cholesterol and fasting blood glucose were measured in Step 3. RESULTS AND CONCLUSION: A total of 5,206 adults (67% females) were surveyed. Tobacco smoking, alcohol drinking and raised blood pressure (BP) were more frequent in males than females, 25% vs 3%, 30% vs 4% and 37% vs 29%. Overweight, physical inactivity and raised cholesterol were more common in females than males, 28% vs 16%, 13% vs 6% and 11% vs 6%. Tobacco smoking was more common in rural than urban areas 11% vs 7%, and overweight and physical inactivity more common in urban than rural areas 39% vs 22% and 24% vs 9%, all with p<0.05. Overall (both sexes) prevalence of tobacco smoking, alcohol consumption, overweight and physical inactivity was 14%, 17%, 22%, 10% and prevalence of raised BP, fasting blood sugar and cholesterol was 33%, 6% and 9% respectively. These data could be useful in the formulation and advocacy of NCD policy and action plan in Malawi.