Contact Isolation for Multidrug-Resistant Infections Not Associated With Increased Adverse Event Risk

Antibiotic resistant superbugs
Researchers conducted a matched cohort study to determine whether contact isolation increases the risk for adverse events among patients with vancomycin-resistant enterococcal infections.

No association was found between contact isolation and an increased risk for adverse events among patients with vancomycin-resistant enterococcal (VRE) infections, according to findings published in JAMA Network Open.

This retrospective cohort study reviewed patient records collected between 2015 and 2017 at the Seoul National University Bundang Hospital in South Korea. Patients who underwent contact isolation due to VRE infection were propensity-score matched in a 1:10 fashion against those with no history of VRE infection who did not undergo contact isolation (controls). To obtain accurate results, the researchers used 2 propensity-score matching methods, including fine stratification and weighting (FSW) and nearest neighbor (NN) matching. The incidence of adverse events were compared between the 2 patient cohorts; the follow-up period was 3 years.

Among patients in the contact isolation (n=177) and control groups (n=93,022), the mean ages were 67.38 and 56.44 years, 55.4% and 53.2% were women, Charlson comorbidity index scores were 2.06 and 0.83, and the mean length of hospitalization was 36.24 and 6.23 days, respectively.

In the NN matching analysis, the researchers compared the incidence of decubitus ulcer and fall events per 1000 patient-days between the 2 groups. They found that decubitus ulcer events occurred at an incidence rate [IR] of 2.54 and fall events at an IR of 0.87 among patients in the contact isolation group vs those in the control group (IR, 1.22 and 1.54, respectively). When these rates were compared between patient groups, the IR ratios for decubitus ulcer, fall, and both events did not significantly differ: 2.09 (95% CI, 0.89-4.92), 0.57 (95% CI, 0.17-1.92), and 1.29 (95% CI, 0.65-2.54), respectively.

Further analysis was performed using Cox proportional hazard regression. In the NN matching analysis, the researchers found that contact isolation was associated with a nonsignificant increased risk for decubitus ulcer (hazard ratio [HR], 2.07; 95% CI, 0.85-5.01; P =.11) and a nonsignificant decreased risk for fall (HR, 0.60; 95% CI, 0.17-2.13; P =.43). Results of both the FSW and NN methods showed no significant group differences in regard to the risk for both events (HR, 1.14; 95% CI, 0.61-2.12 and HR, 1.28; 95% CI, 0.61-2.12, respectively).

An analysis of adverse events among patients who were transferred to the intensive care unit was not possible because only 1 event (fall) occurred among the 21 patients who subsequently underwent contact isolation.

The results of this study may not be generalizable to other hospitals due to variations in both isolation and patient care protocols.

The researchers concluded that because “…no strong evidence of an association between contact isolation and adverse events [was found], contact isolation policy making needs to be carefully decided based on risk-benefit evaluation for each hospital.”


Kang J, Ji E, Kim J, et al. Evaluation of patients’ adverse events during contact isolation for vancomycin-resistant enterococci using a matched cohort study with propensity score.JAMA Netw Open. 2022;5(3):e221865. doi:10.1001/jamanetworkopen.2022.1865