TABLE 1

Incidence rate ratios for detection from screening swabs ≥2 days after admission (a proxy marker of acquisition) in CMFT for all CRE cases, CR E. coli cases, and CR K. pneumoniae cases, modeling the impact of the ward 3 and ward 4 closures and plumbing replacement on acquisition

Location and periodaAll CRE (3,086 cases)CR E. coli (502 cases)CR K. pneumoniae (1,134 cases)
IRR (95% CI)PIRR (95% CI)PIRR (95% CI)P
MHC
    Week 3, 2010, to week 26, 2014 (period 1)0.61 (0.31–1.20)0.150.15 (0.04–0.67)0.0120.19 (0.04–0.82)0.026
    Week 27, 2014, to week 39, 2015 (period 2; reference period)1.001.001.00
    Week 40, 2015, to week 2, 2016 (period 3; wards 3 and 4 closed)
    Week 3, 2016, to week 52, 2016 (period 4)0.11 (0.05–0.22)<0.0010.02 (0.00–0.14)<0.0010.27 (0.09–0.78)0.015
Other hospital locations
    Week 3, 2010, to week 26, 2014 (period 1)2.85 (1.87–4.34)<0.0012.51 (1.57–4.03)<0.0010.75 (0.30–1.86)0.53
    Week 27, 2014, to week 39, 2015 (period 2; reference period)1.001.001.00
    Week 40, 2015, to week 2, 2016 (period 3)0.41 (0.26–0.63)<0.0011.12 (0.61–2.05)0.710.27 (0.17–0.42)<0.001
    Week 3, 2016, to week 52, 2016 (period 4)0.49 (0.32–0.76)0.0020.47 (0.31–0.71)<0.0010.47 (0.28–0.77)0.003
MHC vs other location in reference period (period 2)1.69 (0.81–3.50)0.169.05 (3.98–20.55)<0.0010.45 (0.24–0.86)0.015
Heterogeneity for reduction in MHC vs other location
    Week 3, 2010, to week 26, 2014 (period 1)<0.0010.0010.098
    Week 40, 2015, to week 2, 2016 (period 3)
    Week 3, 2016, to week 52, 2016 (period 4)<0.0010.0030.31
  • a Four time periods were evaluated, as follows: period 1, prior to implementation of a systematic CPE rectal screening policy; period 2, implementation of a CPE rectal screening policy consistent with national guidance; period 3, closure of wards 3 and 4 and replacement of plumbing infrastructure; period 4, reopening of wards 3 and 4 to patient admissions. Period 2 was chosen as the reference period because of the change in screening policies between period 1 and period 2 (see Table S2 and Fig. S6 in the supplemental material), meaning that a greater incidence would be expected in period 2, due to more patients being screened every week. IRR, incidence rate ratio; CI, confidence interval.