Background: A series of infection control measures were introduced at the University Hospitals of Leicester NHS Trust in 2006-2007 to reduce the incidence of Clostridium difficile infection.
Aim: The aim of this study was to assess the impact of these measures on the incidence of C. difficile and to record the associated mortality in hip fracture patients.
Patients and methods: A case matched comparison of mortality was conducted between C. difficile positive patients and C. difficile negative patients admitted with a hip fracture between 1st January 2003 and 30th September 2007. An interrupted time series analysis was performed to assess the effect of various infection control policies on the incidence of C. difficile infection.
Results: The interrupted time series analysis showed that the only effective measure was changing antimicrobial prophylaxis to Co-amoxiclav in May 2007. This reduced the incidence of C. difficile from 7.1 to 1.5% (p<0.001). Six-month mortality in C. difficile positive patients was 71% 1 year before introduction of a diarrhoea treatment policy and 65% 1 year after (p=0.5) indicating treatment was ineffective. A matched cohort comparison over a 57-month period from January 2003 to September 2007 showed that the 6-month mortality was 67% in 170 C. difficile positive patients, 27% in 3247 C. difficile negative patients and 29% in the 170 C. difficile negative matched patients.
Conclusion: This 38% excess mortality indicated that C. difficile increased mortality and did not simply colonise the sickest patients. Changing prophylaxis to Co-amoxiclav was the most effective measure. This reduced the incidence of C. difficile by 80% and thus reduced mortality by prevention rather than cure.