Clostridium Difficile Infection (CDI) is an important cause of healthcare-associated diarrhea, leading to substantial distress and mortality among patients and high financial costs for healthcare services. The majority of CDI cases occur within the hospital (healthcare) setting; however, approximately one quarter of cases are community-associated. Use of antibiotics is a major risk factor for CDI and around a quarter of patients experience CDI recurrence after an initial infection (index). Treatment for CDI depends on the severity and recurrence of infection.
This study aims to use primary care and hospital data from England to describe community-acquired or healthcare acquired CDI in adult patients and to understand their community or hospital provided treatments. Four patient groups will be described according to their infection setting at index (healthcare or community-acquired) and treatment (hospital-treated or community-treated). Study objectives include estimating disease incidence, characterising infection recurrence and determining CDI complications (e.g. inflammatory gastric diseases) and mortality. Furthermore, healthcare resource utilisation (HCRU) including costs will be evaluated. The analysis will be carried out for the four patient groups separately.
Despite existing research examining complications and mortality among CDI patients, studies are often limited by the absence of clinical information outside of the hospital-setting. Despite representing growing sources of concern, both CDI recurrences and community-associated CDI cases remain insufficiently described. This study aims to provide results to fill these evidence gaps in the clinical and economic burden of CDI and CDI recurrence in England.
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.
Incidence of CDI including rCDI; Complications of CDI; All-cause Mortality; HCRU and associated costs
Sarah Jenner - Chief Investigator - IQVIA Ltd ( UK )
Emily Wilkes - Corresponding Applicant - IQVIA Ltd ( UK )
Margherita Bortolini - Collaborator - IQVIA Ltd ( UK )
Peter Egger - Collaborator - IQVIA Ltd ( UK )
Sarah Lay-Flurrie - Collaborator - IQVIA Ltd ( UK )
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation