Showing papers by "Stephen S Lim published in 2010"

Rapid scaling up of insecticide-treated bed net coverage in Africa and its relationship with development assistance for health: a systematic synthesis of supply, distribution, and household survey data.

Abstract: Background Development assistance for health (DAH) targeted at malaria has risen exponentially over the last 10 years, with a large fraction of these resources directed toward the distribution of insecticide-treated bed nets (ITNs). Identifying countries that have been successful in scaling up ITN coverage and understanding the role of DAH is critical for making progress in countries where coverage remains low. Sparse and inconsistent sources of data have prevented robust estimates of the coverage of ITNs over time. Methods and Principal Findings We combined data from manufacturer reports of ITN deliveries to countries, National Malaria Control Program (NMCP) reports of ITNs distributed to health facilities and operational partners, and household survey data using Bayesian inference on a deterministic compartmental model of ITN distribution. For 44 countries in Africa, we calculated (1) ITN ownership coverage, defined as the proportion of households that own at least one ITN, and (2) ITN use in children under 5 coverage, defined as the proportion of children under the age of 5 years who slept under an ITN. Using regression, we examined the relationship between cumulative DAH targeted at malaria between 2000 and 2008 and the change in national-level ITN coverage over the same time period. In 1999, assuming that all ITNs are owned and used in populations at risk of malaria, mean coverage of ITN ownership and use in children under 5 among populations at risk of malaria were 2.2% and 1.5%, respectively, and were uniformly low across all 44 countries. In 2003, coverage of ITN ownership and use in children under 5 was 5.1% (95% uncertainty interval 4.6% to 5.7%) and 3.7% (2.9% to 4.9%); in 2006 it was 17.5% (16.4% to 18.8%) and 12.9% (10.8% to 15.4%); and by 2008 it was 32.8% (31.4% to 34.4%) and 26.6% (22.3% to 30.9%), respectively. In 2008, four countries had ITN ownership coverage of 80% or greater; six countries were between 60% and 80%; nine countries were between 40% and 60%; 12 countries were between 20% and 40%; and 13 countries had coverage below 20%. Excluding four outlier countries, each US$1 per capita in malaria DAH was associated with a significant increase in ITN household coverage and ITN use in children under 5 coverage of 5.3 percentage points (3.7 to 6.9) and 4.6 percentage points (2.5 to 6.7), respectively. Conclusions Rapid increases in ITN coverage have occurred in some of the poorest countries, but coverage remains low in large populations at risk. DAH targeted at malaria can lead to improvements in ITN coverage; inadequate financing may be a reason for lack of progress in some countries. Please see later in the article for the Editors' Summary

Assessing the cost-effectiveness of drug and lifestyle intervention following opportunistic screening for pre-diabetes in primary care

Abstract: Aims/hypothesis This study aims to evaluate the cost-effectiveness of a screening programme for pre-diabetes, which was followed up by treatment with pharmaceutical interventions (acarbose, metformin, orlistat) or lifestyle interventions (diet, exercise, diet and exercise) in order to prevent or slow the onset of diabetes in those at high risk.

Prevention, screening and treatment of colorectal cancer: a global and regional generalized cost effectiveness analysis

Abstract: Regional generalized cost-effectiveness estimates of prevention, screening and treatment interventions for colorectal cancer are presented. Standardised WHO-CHOICE methodology was used. A colorectal cancer model was employed to provide estimates of screening and treatment effectiveness. Intervention effectiveness was determined via a population state-transition model (PopMod) that simulates the evolution of a sub-regional population accounting for births, deaths and disease epidemiology. Economic costs of procedures and treatment were estimated, including programme overhead and training costs. In regions characterised by high income, low mortality and high existing treatment coverage, the addition of screening to the current high treatment levels is very cost-effective, although no particular intervention stands out in cost-effectiveness terms relative to the others. In regions characterised by low income, low mortality with existing treatment coverage around 50%, expanding treatment with or without screening is cost-effective or very cost-effective. Abandoning treatment in favour of screening (no treatment scenario) would not be cost effective. In regions characterised by low income, high mortality and low treatment levels, the most cost-effective intervention is expanding treatment. From a cost-effectiveness standpoint, screening programmes should be expanded in developed regions and treatment programmes should be established for colorectal cancer in regions with low treatment coverage.

Generalized cost-effectiveness analysis of pharmaceutical interventions for primary prevention of cardiovascular disease in Thailand

Abstract: Objectives: To assess the cost-effectiveness of blood pressure (BP)lowering and cholesterol-lowering drugs for cardiovascular disease (CVD) prevention. Methods: We constructed a Markov model in which the Thai population was classified by 10-year absolute CVD risk and modeled the use of BP- and cholesterol-lowering drugs, including a “polypill” (three BP-lowering drugs and a statin). We applied “do-nothing” as the comparator, a health sector perspective on lifetime costeffectiveness, 3% discounting of costs and effects, and used probabilistic sensitivity analysis. Outcomes are expressed as average and incrementalcost-effectivenessinThaibahtperdisability-adjustedlifeyear averted. Results: The polypill would be a very cost-effective option for CVD prevention even in people at modest risk (10-year risk of 5%‐9.9%). Use of the three most cost-effective BP drugs is also associated with a net cost saving and large health gain at risk levels greater than 5%. Adding a generic statin gives a price per disability-adjusted life-year of 0.5 (10-year risk at 20%) to 1.5 (10-year risk at 5%‐9.9%) times Thai per-capita gross domestic product using lowest available annual costs. However, at current average drug prices, adding a statin would be considered cost-effective only for those with a 10-year absolute CVD risk of 20% and more. Conclusions: Primary CVD prevention with the polypill or a combination of three generic BP-lowering drugs is very cost-effective in the Thai population.

Chronic disease prevention: the importance of calls to action

Abstract: prevention and control of chronic diseases. 1 It is an important contribution to efforts to ensure that chronic diseases receive the global and national attention commensurate with their enormous health and economic burdens, especially in low- and middleincome countries. 2 Our call for action is 2-fold: an urgent call to implement policies where we already have the evidence on intervention cost-effectiveness (salt reduction, tobacco control and a multiple drug regime for managing high cardiovascular risk); and a similar call to collect rigorous evidence on other beneficial interventions with the potential for making a difference in populations. Regarding the latter, the editorial confirms our assessment that the absolute effect size of many interventions such as community-based health promotion and changes in saturated and trans-fat intake needs to be confirmed. This is why we called for more rigorous evaluations of these interventions instead of their outright scaling up—an important distinction. Urgent operational research is needed now to identify the best ways to implement effective interventions in communities. However, there is much in the editorial with which we agree. Population growth and ageing are key driving forces of the chronic disease pandemics. The point is clearly made in Figure 2 of the first paper in the Lancet chronic disease series. 2 We note that for the age group of 470 years, the proportion of deaths due to chronic diseases is projected to rise from 87.5% in 2005 to 90.9% in 2030. We agree too that the engagement of clinicians in the chronic disease response will be critical, especially as the health systems strengthening agenda and the reinvigoration

Blood pressure, cholesterol and cardiovascular disease in Thailand

Abstract: Background Although associations between risk factors such as hypertension and hypercholesterolaemia, and cardiovascular disease (CVD) are well-established it is not known to what extent these associations are similar in people from different ethnicities or regions. This study aims to measure the contributions of systolic blood pressure (SBP) and total cholesterol (TC) to ischaemic heart disease (IHD) and stroke in the Thai population. Methods and results Data from a Thai cohort study were used for analyses. Participants were 2702 males and 797 females aged between 35 and 54 years at the start of study in 1985. Cox Proportional Hazards Models were used to assess RRs of IHD or stroke associated with SBP or TC stratified by age at the time of an event of 30–44, 45–59, and 60–69 years. During the 17 years of follow-up, 96 IHD (40 non-fatal, 56 fatal), 69 strokes (32 non-fatal and 37 fatal) occurred. Each 1 mmol/l increase in TC was associated with a fivefold increase in IHD risk in people aged 30–44 years, but not with significant increase in stroke risk in any age group. The RRs (95% CIs) of IHD per 10 mm Hg increase in SBP were 1.31 (1.04 to 1.64) and 1.46 (1.15 to 1.87), and of stroke, 1.40 (1.10 to 1.79) and 1.85 (1.40 to 2.45) in people aged 45–59 and 60–69 years, respectively. Conclusions Increases in IHD and stroke risks associated with these two risk factors observed in Thailand are comparable with those in the Asia Pacific and western populations.