Anyone who enjoyed the discussion on Rose’s Prevention Paradox back in June may find Barton et al’s paper in the BMJ this week interesting. The study aimed to model the cost-effectiveness of population-wide risk-reduction strategies in preventing cardiovascular disease (CVD). Currently, CVD costs the NHS around £30bn each year and this study has been devised to inform the Department of Health via NICE.
While previous studies have already shown that anti-smoking and anti-salt campaigns are cost effective in reducing CVD incidence, this new studies also looked at the effect of other dietary approaches such as trans-fats and saturated fats. Outcomes were measured using mortality figures, life years and QALYs, though the emphasis was on cost savings to the NHS from cases prevented or postponed. A key limitation was the assumption that interventions would result in equal benefit across age groups and socioeconomic groups, and while consideration was made for changes in risk of CVD following the patient’s first event, none was made for subsequent events. The model also did not consider individuals over the age of eighty.
As we would expect from Rose’s theory, a small change in individuals was found to result in a large financial saving to the NHS as well as improved health in the population. This model found that a 1% reduction in the risk of cardiovascular events would save the NHS £30m each year and prevent 25,000 cases of CVD. Furthermore, a reduction in cholesterol concentrations or blood pressure levels of 5% was modelled as saving the NHS between £80m and £100m a year, while lowering mean salt intake from 8.5g to 5.5g would result in around 30,000 fewer cardiovascular events, with savings worth at least £40m a year. The authors also argue that the nature of their model means the calculations are conservative, and the true savings may be worth even more.