Interventions:
The choice of the comparators was appropriate. The "polypill" strategy was supported in previous reports and was compared with a strategy of starting treatment only after hypertension or dyslipidaemia had manifested. The strategy of no preventive treatment is likely to reflect the current pattern of care in several settings.
Effectiveness/benefits:
The authors selected the sources of data in order to use the best available evidence. Thus, no systematic search of sources was carried out. Some information on the design of the primary sources was given. The data were mainly based on large cohort studies or meta-analyses. Aware of the uncertainty surrounding some estimates, the authors undertook an extensive sensitivity analysis which considered reasonable ranges of values for the clinical estimates. The derivation of the benefit measure was not clearly described in terms of the methodology used to obtain the utility values which were used to calculate the QALYs.
Costs:
The authors did not explicitly state the perspective adopted, but the categories of costs appear to suggest the viewpoint of a third-party payer. Some of the sources for economic costs were reported and the most relevant costs (those related to the treatment of the disease) were derived from published studies. The transparency of the analysis was reduced for in two ways. Firstly, the costs were presented as macro-categories without a breakdown of cost items and, secondly, the methodology used to calculate costs was not described. Other aspects of the analysis such as the prices to which the costs referred and the use of discounting were reported.
Analysis and results:
The costs and benefits were synthesised in average cost-utility ratios. Incremental ratios were not required given the dominance of the preventive strategy. The issue of uncertainty was restricted to a deterministic approach, but the assessment of a best-case scenario was appropriate in investigating the conditions under which the less favourable strategy would be preferred. Nevertheless, it turned out that the preventive strategy remained the most cost-effective. The authors acknowledged that non-adherence was not considered, although it might be an issue in real-world settings. The results should be considered specific to the authors’ setting as differences might exist in the baseline risk of CVD between the US population and that of other countries (mainly in terms of the prevalence of obesity).
Concluding remarks:
The study was generally well conducted and was based on valid methodology, although some aspects of the analysis were not extensively reported. Overall, the authors’ conclusions appear to be valid.