Modelling the impact of compliance with dietary recommendations on cancer and cardiovascular disease mortality in Canada.

OBJECTIVES: Despite strong evidence indicating that unbalanced diets relate to chronic diseases and mortality, most adults do not comply with dietary recommendations. To help determine which recommendations could yield the most benefits, the number of deaths attributable to cardiovascular diseases and cancer that could be delayed or averted in Canada if adults changed their diet to adhere to recommendations were estimated. STUDY DESIGN: Macrosimulation based on national population-based survey and vital statistics data. METHODS: A macrosimulation model was used to draw age- and sex-specific changes in relative risks based on the results of meta-analyses of relationship between food components and risk of cardiovascular disease and diet-related cancers. Inputs in the model included Canadian recommendations (fruit and vegetable, fibre, salt, and total-, monounsaturated-, polyunsaturated-, saturated-, and trans-fats), average dietary intake (from 35,107 participants with 24-h recall), and mortality from specific causes (from Canadian Vital Statistics). Monte Carlo analyses were used to compute 95% credible intervals (CI). RESULTS: The estimates of this study suggest that 30,540 deaths (95% CI: 24,953, 34,989) per year could be averted or delayed if Canadians adhered to their dietary recommendations. By itself, the recommendation for fruit and vegetable intake could save as many as 72% (55-87%) of these deaths. It is followed by recommendations for fibres (29%, 13-43%) and salt (10%, 9-12%). CONCLUSIONS: A considerable number of lives could be saved if Canadians adhered to the national dietary intake recommendations. Given the scarce resources available to promote guideline adhesion, priority should be given to recommendations for fruit and vegetable intake.

Stratified cancer screening: the practicalities of implementation.

BACKGROUND: Improving understanding of the genetic basis of disease susceptibility enables us to estimate individuals' risk of developing cancer and offer them disease prevention, including screening, stratified to reflect that risk. Little attention has so far been given to the implementation of stratified screening. This article reviews the issues that would arise in delivering such tailored approaches to prevention in practice. RESULTS: Issues analysed include the organisational context within which implementation of stratified prevention would occur, how the offer of screening would be made, making sure consent is adequately informed, how individuals' risk would be assessed, the age at which risk estimation should occur, and the potential use of genetic data for other purposes. The review also considers how management might differ depending on individuals' risk, how their results would be communicated and their follow-up arranged, and the different issues raised by modification of an existing screening programme, such as that for breast cancer, and the establishment of a new one, for example for prostate cancer. CONCLUSION: Stratified screening based on genetic testing is a radically new approach to prevention. Various organisational issues would need to be considered before it could be introduced, and a number of questions require further research.