Describing the monthly variability of hospital-onset during early coronavirus disease 2019 (COVID-19) using electronic health record data.

OBJECTIVE

To assess the relative risk of hospital-onset (HO-CDI) during each month of the early coronavirus disease 2019 (COVID-19) pandemic and to compare it with historical expectation based on patient characteristics.

DESIGN

This study used a retrospective cohort design. We collected secondary data from the institution's electronic health record (EHR).

SETTING

The Ohio State University Wexner Medical Center, Ohio, a large tertiary healthcare system in the Midwest.

PATIENTS OR PARTICIPANTS

All adult patients admitted to the inpatient setting between January 2018 and May 2021 were eligible for the study. Prisoners, children, individuals presenting with on admission, and patients with <4 days of inpatient stay were excluded from the study.

RESULTS

After controlling for patient characteristics, the observed numbers of HO-CDI cases were not significantly different than expected. However, during 3 months of the pandemic period, the observed numbers of cases were significantly different from what would be expected based on patient characteristics. Of these 3 months, 2 months had more cases than expected and 1 month had fewer.

CONCLUSIONS

Variations in HO-CDI incidence seemed to trend with COVID-19 incidence but were not fully explained by our case mix. Other factors contributing to the variability in HO-CDI incidence beyond listed patient characteristics need to be explored.