Objectives: The aim of this study was to assess compliance with the NICE guidelines and to identify any resulting increase in IE cases or deaths.
Methods: National inpatient hospital activity data for patients discharged from hospitals in England with a diagnosis of IE were obtained and analysed along with AP prescribing data for England from January 2000 to October 2009.
Results: Dentists were responsible for 92% of AP prescriptions using 3g amoxicillin or 600mg clindamycin. After the NICE guidelines, AP prescribing dropped 78% (p<0.0001) from 10,900±1006 (mean±SD) per month to 2417 in October 2009 or a mean of 3,496±1564. Although there was an upward trend in IE cases and deaths from 2000-2009 it's slope did not increase in the 18 months following the NICE guidelines and using a pre-specified “non-inferiority” statistical test we were unable to demonstrate a significant increase in IE cases, IE deaths, or IE cases with a possible OVGS origin after NICE. We continue to monitor the data.
Conclusions: A significant decrease in AP prescribing in the UK has not resulted in a detectable increase in IE cases or deaths. Thus the “benefits” of continuing AP in other parts of the world may need to be re-evaluated. These findings also support evidence that the risk of IE causing bacteraemia due to dental procedures may be small compared to the transient bacteraemias associated with mastication and oral hygiene procedures, particularly in those with poor oral hygiene.