Clostridioides difficile Module 2 Risk-of-bias-tabel

Risk of bias table for interventions studies (cohort studies based on risk of bias tool by the CLARITY Group at McMaster University)

Author, year Selection of participants Exposure Outcome of interest Confounding-assessment Confounding-analysis Assessment of outcome Follow up Co-interventions Overall risk of bias

 

Was selection of exposed and non-exposed cohorts drawn from the same population?

Definitely yes,
probably yes,
probably no,
definitely no

Can we be confident in the assessment of exposure?


Definitely yes,
probably yes,
probably no,
definitely no

Can we be confident that the outcome of interest was not present at start of study?

Definitely yes,
probably yes,
probably no,
definitely no

Can we be confident in the assessment of confounding factors?

Definitely yes,
probably yes,
probably no,
definitely no

Did the study match exposed and unexposed for all variables that are associated with the outcome of interest or did the statistical analysis adjust for these confounding variables?

Definitely yes,
probably yes,
probably no,
definitely no

Can we be confident in the assessment of outcome?

Definitely yes,
probably yes,
probably no,
definitely no

Was the follow up of cohorts adequate? In particular, was outcome data complete or imputed?

Definitely yes,
probably yes,
probably no,
definitely no

Were co-interventions similar between groups?

Definitely yes,
probably yes,
probably no,
definitely no

Low,
some concerns,
high

Jabbar, 2010

Definitely yes

Reason: Ten healthy volunteers, all of them nonclinical research personnel at Hines VA Hospital

Definitely yes

Reason: 2/10 had minor CFU preincolation and 8/10 had no CFU preincolation indicating no infection

Definitely yes

Reason: Outcome is based on direct culture following inoculation

Not applicable

Not applicable

Definitely yes

Reason: Culturing on selective medium.

Not applicable

Not applicable

Low

Knight, 2010

Definitely yes

Reason: All patients fulfilling selection criteria were included

Definitely yes

Reason: All in-patients with a diagnosis of CDAD were identified by ICD-9 code from medical records database or by positive C difficile toxin assay from the microbiology laboratory database.

Probably no

Reason: There was no screening upon admission it was unclear if patients were infected in hospital as a result of hospital transmission

Not applicable

Not applicable

Definitely yes

Reason: Throughout the study period, C difficile assays were performed using an enzyme immunoassay

Not applicable

No information

Some concerns

Kundrapu, 2014

Definitely yes

Reason: All were hospital patient that fulfilled inclusion criteria

Definitely yes

Reason: Patients with CDI Clostridioides difficile-infectie (Clostridioides difficile-infectie ) or asymptomatic carriers of toxigenic C. difficile identified through rectal surveillance cultures

Definitely yes

Reason: Patients were only included if positive

Not applicable

Not applicable

Probably no

Reason: Only 14/44 (32%) patients had positive hand cultures before hand hygiene meaning the outcome was not present prior to the intervention

Not applicable

No information

Some concerns

Oughton, 2009

Definitely yes

Reason: Ten hospital laboratory workers volunteered for this study

Definitely yes

Reason: Culturing on selective medium

Probably no

Reason: No screening prior to exposure. Unclear is outcome was present at the beginning of the intervention or during repeated interventions.

Not applicable

Not applicable

Definitely yes

Reason: each hand was placed into a new glove containing 20 mL of sterile brain-heart infusion broth, which was gently dispersed for 30 seconds. A 1 mL sample of the broth was removed via pipette for quantification by serial 10-fold dilution on CCFA-T and incubated anaerobically at 37 C for 48 hours.

Not applicable

No information

Some concerns