The authors did not report the inclusion criteria used in the literature review and the relevance and validity of the primary studies used to provide estimates for the model were not demonstrated. These estimates may consequently be subject to bias. Furthermore, the authors' predictions rest upon a number of key assumptions. Firstly, the health promotion programmes are assumed to be effective in reducing population levels of dietary saturated fat intake. In addition, the authors presuppose that these reductions are uniformly applicable to different population subgroups. Lastly, a causal, linear relationship is assumed between dietary saturated fat intake, serum cholesterol levels and the risk of CHD. No sensitivity analysis was conducted to investigate the implications of varying these assumptions.
No details of the costs or contents of the population health promotion programmes used were given, other than the assumptions concerning efficacy. Costs and quantities were not reported separately, nor was any detail of the breakdown in costs given. It is therefore not possible to validate the authors' findings.
The model is formulated for the US population; if dietary saturated fat intake, serum cholesterol levels or the incidence of CHD differed in other settings, then the findings might not be generalisable.
Since study findings are based on a number of key assumptions, reflecting the uncertainties in the data, the authors' conclusions are not justified.