Table 3

Multivariable binary generalised estimating equations (GEE) regression modelling the impact of patient and hospital-level predictors on the patient-level risk of Clostridium difficile infection

Adjusted OR95% CIp Value
Patient characteristic
Age group (years)
 1–100.150.07 to 0.31<0.001
 11–170.190.10 to 0.39<0.001
 18–440.520.44 to 0.62<0.001
 45–640.610.54 to 0.69<0.001
 65–740.770.68 to 0.87<0.001
 75–841.001.001.00
 ≥851.121.00 to 1.260.05
Female sex1.281.18 to 1.40<0.001
Admission type
 Medical2.302.01 to 2.64<0.001
 Obstetrical0.040.015 to 0.091<0.001
 Surgical1.001.001.00
 Other2.521.29 to 4.920.007
Elective admission0.550.46 to 0.65<0.001
Infection as most responsible diagnosis0.900.78 to 1.020.10
Previous diagnoses
 Myocardial infarction0.850.72 to 1.010.06
 Congestive heart failure1.411.24 to 1.59<0.001
 Peripheral vascular disease2.111.72 to 2.58<0.001
 Cerebrovascular disease0.930.77 to 1.120.42
 Dementia1.391.20 to 1.60<0.001
 Chronic obstructive pulmonary disease1.171.03 to 1.330.014
 Rheumatological disease1.551.10 to 2.180.012
 Peptic ulcer disease2.051.57 to 2.68<0.001
 Diabetes mellitus1.030.93 to 1.140.57
 Hemiparesis/paraplegia2.041.49 to 2.79<0.001
 Renal disease1.441.23 to 1.69<0.001
 Malignancy1.181.03 to 1.350.020
 Liver disease2.051.64 to 2.56<0.001
 HIV1.560.50 to 4.910.45
 Inflammatory bowel disease2.431.78 to 3.32<0.001
 Other immunocompromise2.191.67 to 2.88<0.001
Healthcare exposure in preceding 8 weeks
 Hospital admission1.641.31 to 2.05<0.001
 Emergency department visit0.800.53 to 1.210.29
 Past gastrointestinal procedure1.150.91 to 1.460.24
 Same-day surgery procedure1.070.88 to 1.300.49
 Nursing home stay1.080.73 to 1.600.71
 Haemodialysis1.290.96 to 1.750.09
 Chemotherapy0.890.68 to 1.150.37
 Homecare treatment1.371.25 to 1.52<0.001
 Recent diagnosis of infection1.561.02 to 2.380.038
Calendar month of admission
 January0.930.75 to 1.140.49
 February1.030.84 to 1.260.80
 March0.900.73 to 1.110.31
 April1.080.90 to 1.290.42
 May0.960.79 to 1.150.64
 June1.030.85 to 1.240.78
 July1.001.001.00
 August1.060.87 to 1.290.59
 September0.750.60 to 0.930.01
 October0.900.73 to 1.110.32
 November0.870.70 to 1.070.18
 December0.850.69 to 1.060.15
Hospital characteristic
Hospital type
 Academic/teaching2.131.55 to 2.93<0.001
 Large community1.831.38 to 2.42<0.001
 Medium community1.771.38 to 2.36<0.001
 Small community1.001.001.00
Proportion of beds in single-bed rooms
 <25%1.001.001.00
 25%–35%1.160.86 to 1.550.34
 >35%1.160.92 to 1.470.21
 Not available1.130.82 to 1.550.45
Baseline C. difficile rates in fiscal year 20071.021.01 to 1.030.010
Testing method for C. difficile
 Standard culture followed by cytotoxin assay0.900.66 to 1.220.49
 PCR1.401.03 to 1.910.03
 Toxin A/B testing by commercial enzyme assay0.920.66 to 1.300.65
 Other1.001.001.00
Hospital processes of care
 Immediate isolation for patients with diarrhoea0.930.66 to 1.220.56
 Audit of compliance for antibiotic stewardship1.170.92 to 1.500.20
 Audit of compliance of environmental cleaning1.290.99 to 1.670.06
 Reporting to CEO or hospital board0.970.77 to 1.210.78
 On-site C. difficile diagnostic testing0.870.68 to 1.100.24
 Use of vancomycin as first-line treatment1.190.87 to 1.630.28
  • CEO, chief executive officer.