Context

The number of people with hypertension is anticipated to increase despite greater awareness of the condition as a risk factor for cardiovascular disease (CVD) and more options for treatment. Clinical guidelines are evidence-based recommendations used to inform clinician practice when treating an individual patient. Regular updates of guidelines are important to ensure their ongoing relevance. Moran and colleagues investigated the potential cost implications in the USA if the management of hypertension aligned with the updated USA guidelines.1

Findings

The authors report from their simulation modelling that approximately 860 000 people with existing CVD and hypertension that are not being treated with an antihypertensive would be eligible for treatment every year. Treatment of these cases was predicted to result in 16 000 fewer CVD events and 6000 fewer deaths associated with CVD. In terms of primary prevention benefits, among the 8.6 million people aged 35–74 years with hypertension and no prior CVD achieving guideline targets was cost-saving or cost-effective (cost/QALY gained <US$50 000) for all groups with the exception of women aged between 35 and 44 years with stage one hypertension.

Commentary

The results produced appear very favourable given the many scenarios found to be cost-saving, more so than in other studies.3 ,4 There may be several reasons for this, including that most modelling studies are problematic to compare given the different methods, data sources and assumptions used. The use of a range of data sources and some which included self-reported data, may also introduce various forms of bias. However, the authors have undertaken a range of sensitivity and uncertainty analyses to account for such sources of uncertainty for input parameters driving the results.

This research provides important confirmatory evidence that treatment of hypertension, as part of prevention efforts for reducing the impact of CVD, remains a worthwhile investment. The number of people with existing CVD who should be on antihypertensive therapy was possibly underestimated since patients with stroke may benefit from lowering blood pressure regardless of their initial blood pressure level.5 Furthermore, achieving therapeutic thresholds is difficult and there are many people on inadequate treatment. Other authors have argued that changing from single risk factor thresholds as a basis for primary prevention of CVD to an absolute risk approach is highly recommended since this may lead to further substantial reductions in health sector spending by more efficiently directing preventive drug therapies to those at greater overall risk.3

The authors explain that the changes to the US recommendations mean that 1% of young adults and 8% of older adults now become ineligible to receive prevention treatment in the form of medication. It is difficult to account for the fact that withdrawing treatment for those no longer eligible may not occur and this may diminish the overall cost-effectiveness of the guideline. Further, there are many barriers to the management of hypertension and evidence-based recommendations are not always followed. Therefore, the cost-savings may be overestimated.

Implications for practice

Treatment of hypertension is important as primary prevention and in secondary prevention of CVD. Consideration of treatment in younger people should take into account the presence of other risk factors since treatment may still be justified if they are at high absolute risk of developing CVD within a 5 or 10-year timeframe.