Scholze et al. BMC Public Health 2010, 10:529 http://www.biomedcentral.com/1471-2458/10/529 Page 5 of 12 Figure 2 Proportion of the hypertensive population > 20 years within each risk group; 2008-2020. incident cardiovascular disease constituted 67% and 22% of total costs respectively in Germany in 2008 (figure 4). In Spain these proportions were 50% and 37% and in Italy were 71% and 17%. Hypertension drug costs and physician costs relating to the management of hyperten- sion constituted the smallest proportion of total costs in all countries (figure 4). Mean annual costs per hypertensive patient were around three-fold higher in subjects with MetS com- pared to those without and rose incrementally with the additional number of MetS components present (figure 5). The greatest increment in per patient costs was from no metabolic components present to one where there was a two-fold increase after which the costs increased by around 1.2 to 1.8 fold with each additional component. Sensitivity analysis A number of sensitivity analyses were conducted (table 3). The total annual cost-of-illness of hypertension, with and without the presence of MetS did not vary signifi- cantly from the base case, with the exception of only including cases of incident or new onset diabetes rather than prevalent type 2 diabetes. In particular, in Germany by only including incident type 2 diabetes reduced the cost of hypertension with MetS from €24,427 million to €8,753 million. There was also a greater degree of varia- tion in total costs when cardiovascular and type 2 Figure 3 Prevalence of individual components of MetS in patients with hypertension; 2008 and 2020.