Spatiotemporal clustering of in-hospital Clostridioides difficile infection

Abstract

Objective: To determine whether Clostridioides difficile infection (CDI) exhibits spatiotemporal interaction and clustering.Design: Retrospective observational study.Setting: The University of Iowa Hospitals and Clinics.Patients: This study included 1,963 CDI cases, January 2005 through December 2011.Methods: We extracted location and time information for each case and ran the Knox, Mantel, and mean and maximum component size tests for time thresholds (T = 7, 14, and 21 days) and distance thresholds (D = 2, 3, 4, and 5 units; 1 unit = 5-6 m). All tests were implemented using Monte Carlo simulations, and random CDI cases were constructed by randomly permuting times of CDI cases 20,000 times. As a counterfactual, we repeated all tests on 790 aspiration pneumonia cases because aspiration pneumonia is a complication without environmental factors.Results: Results from the Knox test and mean component size test rejected the null hypothesis of no spatiotemporal interaction (P