'Matching Michigan': a 2-year stepped interventional programme to minimise central venous catheter-blood stream infections in intensive care units in England

Abstract

Background: Bloodstream infections from central venous catheters (CVC-BSIs) increase morbidity and costs in intensive care units (ICUs). Substantial reductions in CVC-BSI rates have been reported using a combination of technical and non-technical interventions.

Methods: We conducted a 2-year, four-cluster, stepped non-randomised study of technical and non-technical (behavioural) interventions to prevent CVC-BSIs in adult and paediatric ICUs in England. Random-effects Poisson regression modelling was used to compare infection rates. A sample of ICUs participated in data verification.

Results: Of 223 ICUs in England, 215 (196 adult, 19 paediatric) submitted data on 2479 of 2787 possible months and 147 (66%) provided complete data. The exposure rate was 438 887 (404 252 adult and 34 635 paediatric) CVC-patient days. Over 20 months, 1092 CVC-BSIs were reported. Of these, 884 (81%) were ICU acquired. For adult ICUs, the mean CVC-BSI rate decreased over 20 months from 3.7 in the first cluster to 1.48 CVC-BSIs/1000 CVC-patient days (p<0.0001) for all clusters combined, and for paediatric ICUs from 5.65 to 2.89 (p=0.625). The trend for infection rate reduction did not accelerate following interventions training. CVC utilisation rates remained stable. Pre-ICU infections declined in parallel with ICU-acquired infections. Criterion-referenced case note review showed high agreement between adjudicators (κ 0.706) but wide variation in blood culture sampling rates and CVC utilisation. Generic infection control practices varied widely.

Conclusions: The marked reduction in CVC-BSI rates in English ICUs found in this study is likely part of a wider secular trend for a system-wide improvement in healthcare-associated infections. Opportunities exist for greater harmonisation of infection control practices. Future studies should investigate causal mechanisms and contextual factors influencing the impact of interventions directed at improving patient care.

Figure 1

Central venous catheter (CVC)-blood stream infection (BSI) rates. (A) Total adult and paediatric CVC-BSI infection rate (——) and CVC utilisation ratio % (……) by quarter. (B) Ratio of intensive care unit (ICU)-acquired to (pre-ICU+ICU-acquired) CVC-BSIs. (C) Adult CVC-BSI infection rate (——) and CVC utilisation ratio % (……) by quarter. (D) Adult ICU CVC-BSI rates by cluster. (E) Paediatric CVC-BSI infection rate (——) and CVC utilisation ratio % (……) by quarter. (F) Paediatric CVC-BSI rates by cluster.