Assessing the clinical and economic burden among patients with Clostridium Difficile Infection and recurrent Clostridium Difficile Infections: A real-world evidence study

Date of Approval
Application Number
Technical Summary

This is a retrospective cohort study including adult patients diagnosed with CDI between 1st January 2015 and 31st December 2019, with first CDI diagnosis as index date. The index CDI diagnosis must not be preceded by another CDI episode within the previous 8 weeks.
Four cohorts will be created according to index CDI setting, identified using CPRD-HES linked data, (healthcare or community-acquired) and treatment (hospital-treated or community-treated).

Person characteristics (age, gender) and medical history (procedures, treatments, comorbidities) will be evaluated 12 months preceding index date and patient outcomes will be assessed over the follow-up period of up to 24 months after index date.

CDI episodes post index that occur within 8 weeks of a previous episode are defined as recurrent episodes (rCDI).
Study outcomes include index and recurrent CDI episodes, CDI complications, all-cause and excess mortality and HCRU.

Annual incidence rates of CDI and recurrence will be reported.
Time between CDI episodes will be described using non-parametric Kaplan-Meier analyses.
Incidence of CDI complications up to 12 months post-index will be analysed using adjusted Cox regression analyses. Crude all-cause mortality rate of CDI patients will be estimated up to 24 months post index.
Excess mortality will be assessed by matching CDI patients 1:5 to non-CDI patients and estimating the difference in incidence death rates.
‘Standard of care’ Sankey diagrams of patients’ treatment pathway from index to end of follow-up will be presented.

HCRU up to 12 months post-index per patient and per incremental CDI episode will be reported alongside associated costs.
A matched cohort design will be used to estimate difference in cumulative HCRU costs due to CDI for CDI, recurrent CDI and non-CDI patients up to 12 months post index.

Analysis will be stratified by various covariates (e.g. age, gender, number of recurrence) as specified per study objective.

Health Outcomes to be Measured

Incidence of CDI including rCDI; Complications of CDI; All-cause Mortality; HCRU and associated costs


Sarah Jenner - Chief Investigator - IQVIA Ltd
Emily Wilkes - Corresponding Applicant - IQVIA Ltd
Margherita Bortolini - Collaborator - IQVIA Ltd
Peter Egger - Collaborator - IQVIA Ltd
Sarah Lay-Flurrie - Collaborator - IQVIA Ltd


HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation