Hospital Occupancy Influences C. difficile Infection Rates

Mahshid Abir, MD, MSc

The more occupied the hospital is, the lower the chance for developing Clostridium difficile (C. difficile) infection is for patients, according to a recent report.

Researchers from University of Michigan Medical School investigated the relationship between high hospital occupancy and rates of hospital acquired C. difficile. The researchers used a novel measurement of hospital occupancy, analyzing administrative data across a 4-year period plus daily census data to piece together occupancy reports. They split hospital occupancy levels into 4 groups: 0.00-0.25 (low occupancy); 0.26-0.50; 0.51-0.75; and 0.76-1.00 (high occupancy).

The patients were all over 65 years of age and admitted to the hospital via the emergency department with an average length of stay of less than 50 days. If they stayed any longer or were admitted to the hospital via other methods, the researchers excluded them because they were likely sicker and could influence the study results.

Of the 558,829 discharges the researchers identified across 327 hospitals, there were 2045 admissions with C. difficile infection. The 0.26-0.50 occupancy group did not have a significantly higher rate of infection than the low occupancy group, the researchers reported. The 0.51-0.75 group and the high occupancy group had 15% lower odds of C. difficile infection compared to the low occupancy group, they determined.

The mid-levels of occupancy had more than 3-fold increased odds of C. difficile infection compared to the low occupancy group, they found. But, they added, the high and low occupancy groups did not have significantly different C. difficile infection odds.

“We expected that when hospitals get busier, rates of hospital-acquired infections would go up—with staff being less compliant with hand hygiene and other related protocols given heavier workloads,” study author Mahshid Abir, MD, MSc explained to MD Magazine®. “However, we found that rates of infection were highest when a hospital is at its average occupancy and that infection rates drop at higher occupancy.”

Abir said that the team’s findings should prompt hospital administrators to evaluate operational changes during periods of high occupancy in order to protect their facilities from hospital acquired infections. Questions about staffing, implementation of policies, and routine procedures during low and high occupancy times need to be addressed. Also understanding what functions of care perform well during low and high periods of occupancy—but that may fall by the wayside in periods of intermediate occupancy—would serve hospital planners and administrators well.

“These data suggest that hospital occupancy level should be a routinely collected data element by infection control officers and that this should be linked with protocols triggered or modified with high or low occupancy that might affect hospital acquired infections,” the researchers suggested.

A similar European study determined that increased hospital acquired infections were tied to increased occupancy, though that study did not account for infections present at a patient’s hospital admittance. Additionally, that study did not include minimum nursing staffing policy, which was an enacted policy included in the researcher’s analysis.

The paper, “The Association of Inpatient Occupancy with Hospital-Acquired Clostridium difficile Infection,” was published in The Journal of Hospital Medicine.