Fig. 2

Diagram to facilitate explanation of the effect of AP in reducing the risk of IE following IDPs performed in high-risk patients. Each stack contains 1,000 yellow blocks representing 1,000 high-risk individuals undergoing IDPs (of all types), dental extractions or oral surgical procedures. Red blocks represent the number of individuals within each 1,000 population who would develop IE following the procedure in the absence of antibiotic cover (AP) (upper row). Blue blocks represent the number of individuals within each 1,000 population that would develop IE if each received AP before the procedure (lower row). Note: the incidence of IE following invasive dental procedures covered by AP is less than 1:1,000 (three in 10,000). The risk of a non-fatal adverse reaction following AP is even lower still (two in 100,000) and too small to feature in this figure. Data shown here are derived from a US study of patients with employer-provided medical/dental insurance cover.¹⁴ A similar study in Medicaid patients found generally higher values and it is therefore possible that the values shown are under-estimated for some patient groups.¹⁵ However, AP was equally effective in reducing the incidence of IE in both studies