Elsevier

The Lancet

Volume 370, Issue 9604, 15–21 December 2007, Pages 2044-2053
The Lancet

Series
Chronic disease prevention: health effects and financial costs of strategies to reduce salt intake and control tobacco use

https://doi.org/10.1016/S0140-6736(07)61698-5Get rights and content

Summary

In 2005, WHO set a global goal to reduce rates of death from chronic (non-communicable) disease by an additional 2% every year. To this end, we investigated how many deaths could potentially be averted over 10 years by implementation of selected population-based interventions, and calculated the financial costs of their implementation. We selected two interventions: to reduce salt intake in the population by 15% and to implement four key elements of the WHO Framework Convention on Tobacco Control (FCTC). We used methods from the WHO Comparative Risk Assessment project to estimate shifts in the distribution of risk factors associated with salt intake and tobacco use, and to model the effects on chronic disease mortality for 23 countries that account for 80% of chronic disease burden in the developing world. We showed that, over 10 years (2006–2015), 13·8 million deaths could be averted by implementation of these interventions, at a cost of less than US$0·40 per person per year in low-income and lower middle-income countries, and US$0·50–1·00 per person per year in upper middle-income countries (as of 2005). These two population-based intervention strategies could therefore substantially reduce mortality from chronic diseases, and make a major (and affordable) contribution towards achievement of the global goal to prevent and control chronic diseases.

Introduction

80% of global deaths from chronic diseases—mainly cardiovascular disease, cancer, chronic respiratory disease, and diabetes—are in low-income and middle-income countries. Demographic changes in these countries are expected to increase the proportion of deaths attributable to these causes from just over half in 2002 to 61% by 2015.1

The WHO Comparative Risk Assessment project estimated the number of deaths from chronic diseases which could potentially be averted if the distributions of major risk factors were reduced.2 In this and the following paper of the Series, we aimed to assess selected intervention strategies—for which scaled-up coverage can be justified on the basis of sufficient information and evidence3—to see what contribution they could make towards achievement of the goal to reduce rates of mortality from chronic diseases worldwide by an additional 2% per year for the next 10 years.4 We used the WHO's framework for classification of individual and population-based interventions as core, expanded, or optimum (in terms of their effectiveness, cost, acceptability, and feasibility).5 In this paper, we address two population-based strategies: salt reduction and tobacco control. The next paper in this Series assesses interventions for treatment of individuals at high risk of cardiovascular disease.6 Taken together, these population-level and individual-level strategies could be the first elements of a package of chronic disease prevention and control, to which other interventions could be added.

This analysis complements other efforts, including those related to the Millennium Development Goals, to estimate the cumulative financial and health consequences of scaling up coverage for intervention strategies.7, 8 The purpose, methods, and perspective of such analyses are distinct from the economic assessment of the cost-effectiveness of interventions (which aims to identify increased efficiency or best buys across the health sector, and which covers a broader set of potential costs and effects).5, 9 Other research has assessed the cost-effectiveness of salt-reduction and tobacco-control strategies in the context of low-income and middle-income countries, and shown that both are highly efficient uses of societal resources.10, 11, 12, 13

Key messages

  • 23 countries have 80% of the burden of chronic disease in low-income and middle-income regions of the world

  • In these countries, 13·8 million deaths could be averted over 10 years from 2006 to 2015 (8·5 million by a salt-reduction strategy and 5·5 million by implementation of four elements of the WHO Framework Convention on Tobacco Control)

  • Most deaths averted would be from cardiovascular diseases (75·6%), followed by deaths from respiratory diseases (15·4%) and cancer (8·7%)

  • The cost of implementing these two interventions would be less than US$0·40 per person per year in low-income and lower middle-income countries, and US$0·50–1·00 per person per year in upper middle-income countries (as of 2005)

  • Although large absolute numbers of deaths could be averted with these selected interventions, they nevertheless account for only a small fraction of the total burden of chronic disease deaths

Section snippets

Reduction in salt consumption

Two meta-analyses of randomised controlled trials that examined the long-term effects of salt reduction in people with and without hypertension have shown that moderate reductions in salt intake (of 2–4·6 g per day) can reduce absolute systolic blood pressure by a small but important amount.14, 15 One of these meta-analyses showed that the size of the decrease in blood pressure was correlated with that of the reduction in salt intake.14 Furthermore, similar reductions in salt intake can cause

Analytical framework

For each of the 23 countries, and for all years between 2006 and 2015, we used methods from the WHO Comparative Risk Assessment project to estimate the effects of successful implementation of the two strategies.37 We calculated the proportion of chronic disease deaths from specific causes (see webtable 4) that could be averted if the distributions of mean systolic blood pressure and tobacco exposure were shifted to lower levels (the “potential impact fraction”) for different age-groups and

Salt interventions

We used data from the Intersalt study, which had the most comprehensive and consistent cross-population estimates of urinary salt excretion to date, to estimate projected salt intake if future consumption continued to follow recent trends (business-as-usual salt intake).17 Accurate longitudinal data for trends in salt consumption in low-income and middle-income countries are scarce, although recent reviews of mean salt consumption within populations showed that, with the exception of a few

Financial costs of implementation

Our selected population-based interventions will not require expenditures by patients or health-care providers. However, the interventions will depend on programmatic resource inputs for planning, implementation, and monitoring. Examples of activities with substantial resource consequences include: national and provincial meetings for strategic planning and monitoring of the programmes; national surveillance at the household level to assess changing rates of consumption of salt and tobacco;

Sensitivity analysis

We assessed the effects of doubling the reduction in salt consumption to achieve a 30% decrease from baseline values, and of decreasing salt intake to the limit recommended by the WHO of 5 g per day. We also tested the sensitivity of the results by substitution of alternative coefficients for the conversion of salt intake to changes in blood pressure, from the Intersalt study (webtable 6).16, 60, 61 For tobacco interventions, we incorporated higher and lower estimates of the effects of

Deaths averted

Our findings show that over 10 years (2006–15), 13·8 million deaths could be averted if the selected measures to reduce tobacco and salt exposure were implemented (figure 1). 8·5 million deaths would be averted by implementation of the salt-reduction strategy alone, and 5·5 million by implementation of the four elements of the WHO FCTC alone. Most of the deaths averted (75·6%) would be from cardiovascular diseases, followed by deaths from respiratory disease (15·4%) and cancer (8·7%) (table 2).

Potential impact fractions

Potential impact fractions for tobacco-control interventions (deaths averted by the interventions as a proportion of total possible deaths from chronic diseases) were highest in Indonesia, Poland, Thailand, and South Africa. In these countries, high tobacco exposures are combined with large price elasticities for tobacco products; thus, the moderate increases in real price that we modelled would manifest as many deaths averted. Potential impact fractions for salt-reduction interventions were

Financial cost estimates

Figure 3 and webtable 7 show the estimated financial costs associated with implementation of the selected interventions. Total expenditure for implementation of both strategies would range from $0·14 to $0·38 per person per year in low-income and lower middle-income countries, and from $0·52 to $1·04 per person per year in upper middle-income countries (webtable 7). The ranges in each group are primarily caused by differences in the prices or unit costs of programme inputs (such as salaries).

Results of sensitivity analysis

Table 3 shows the sensitivity of estimates for avertable mortality and impact fraction to variations in the reduction of exposure to risks from tobacco and salt that could be achieved, and in the effectiveness of non-price interventions for tobacco control. Moreover, the results varied according to the coefficients used to calculate the conversion of changes in salt intake to reduced blood pressure (webtable 6). We calculated that the number of deaths that would be averted by salt interventions

Discussion

Our investigation has highlighted the continuing high toll of tobacco deaths in regions where the tobacco epidemic is developing fastest, and the large number of potentially avertable deaths from cerebrovascular and hypertensive diseases in regions of high salt consumption. Our results show that 13·8 million deaths from chronic diseases could be averted over a 10-year period (2006–15) in 23 low-income and middle-income countries by implementation of a few population-based interventions. This

References (66)

  • SS Lim et al.

    Prevention of cardiovascular disease in high-risk individuals in low-income and middle-income countries: health effects and costs

    Lancet

    (2007)
  • B Johns et al.

    Estimated global resources needed to attain universal coverage of maternal and newborn health services

    Bull World Health Organ

    (2007)
  • K Stenberg et al.

    A financial road map to scaling up essential child health interventions in 75 countries

    Bull World Health Organ

    (2007)
  • DB Evans et al.

    Time to reassess strategies for improving health in developing countries

    BMJ

    (2005)
  • K Shibuya et al.

    WHO framework convention on tobacco control: Development of an evidence based global public health treaty

    BMJ

    (2003)
  • MK Ranson et al.

    Global and regional estimates of the effectiveness and cost-effectiveness of price increases and other tobacco control policies

    Nicotine Tob Res

    (2002)
  • WKJ Willett et al.

    Prevention of chronic disease by means of diet and lifestyle change

  • FJ He et al.

    Effect of longer-term modest salt reduction on blood pressure

    Cochrane Database Syst Rev

    (2004)
  • L Hooper et al.

    Advice to reduce dietary salt for prevention of cardiovascular disease

    Cochrane Database Syst Rev

    (2004)
  • Intersalt: An international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion. Intersalt cooperative research group

    BMJ

    (1988)
  • MR Law et al.

    By how much does dietary salt reduction lower blood pressure? I–analysis of observational data among populations

    BMJ

    (1991)
  • JJ Carvalho et al.

    Blood pressure in four remote populations in the intersalt study

    Hypertension

    (1989)
  • C Nagata et al.

    Sodium intake and risk of death from stroke in Japanese men and women

    Stroke

    (2004)
  • J He et al.

    Dietary sodium intake and incidence of congestive heart failure in overweight us men and women: first national health and nutrition examination survey epidemiologic follow-up study

    Arch Intern Med

    (2002)
  • NR Cook et al.

    Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

    BMJ

    (2007)
  • Diet, nutrition and the prevention of chronic diseases: report of a joint WHO/FAO expert consultation. WHO Technical Report Series, No. 916

    (2003)
  • Reducing salt intake in populations. Report of a WHO forum and technical meeting

    (2007)
  • MR Law et al.

    By how much does dietary salt reduction lower blood pressure? III–analysis of data from trials of salt reduction

    BMJ

    (1991)
  • FJ He et al.

    Effect of modest salt reduction on blood pressure: a meta-analysis of randomized trials. Implications for public health

    J Hum Hypertens

    (2002)
  • HG Tian et al.

    Changes in sodium intake and blood pressure in a community-based intervention project in China

    J Hum Hypertens

    (1995)
  • T Forrester et al.

    A randomized trial on sodium reduction in two developing countries

    J Hum Hypertens

    (2005)
  • FP Cappuccio et al.

    A community programme to reduce salt intake and blood pressure in Ghana

    BMC Public Health

    (2006)
  • M Nakamura et al.

    Feasibility and effect on blood pressure of 6-week trial of low sodium soy sauce and miso (fermented soybean paste)

    Circ J

    (2003)
  • Cited by (0)

    View full text