Interhospital Transfer is an Independent Risk Factor for Hospital-acquired Infection

Author(s):
Camden Gardner; Ilan Rubinfeld; Arielle Hodari Gupta; Jeffrey Johnson

Background:

Regionalization of surgical care shifts patients with higher disease burdens and acuity to tertiary and quaternary centers. Further, transfer criteria are highly variable, and there is opportunity for harm in delay and miscommunication. Hospital-acquired infections (HAIs) are increasingly important quality measures with critical financial implications. We examined the role for interhospital transfer in our cases of HAI across a large multihospital system focusing on National Healthcare Safety Network (NHSN) labelled infections submitted to the CDC and found in the Center for Medicare & Medicaid Services (CMS) value-based purchasing (VBP) program.

Hypothesis:

Surgical patients transferred to a regional multihospital system have a higher risk of NHSN labelled HAIs.

Methods:

The analysis cohort was filtered from a five-hospital health system administration registry containing inpatients admitted from 2014 to Fall of 2021. The study group included all adult surgical inpatients as defined by AHRQ. The dataset contained demographics, health characteristics, and variables reflecting disease severity, along with the NHSN defined HAIs of CLABSI, CAUTI, and C. difficile infection. Univariate statistical tests and multivariate logistic regression were performed to highlight the relationship between patient variables, including transfer status, and the occurrence of HAIs. The data was de-identified prior to analysis and deemed exempt from IRB review. Data was analyzed using R within R-Studio.

Results:

The surgical cohort had a total of 31435 patients of which 1611 (5.1%) were transfers. The overall rate of HAIs was 1.8% (567) with 86 (0.3%) cases of CLABSI, 138 (0.4%) cases of CAUTI, and 359 (1.1%) cases of C. difficile infection. Across the three HAIs of interest the rate was higher in transfer patients compared to non-transfer patients at the univariate level (CLABSI: 1.1% vs. .02%, [OR: 4.94, p-value: <0.001]; CAUTI: 1.6% vs 0.4% [OR: 4.14, p-value: <0.001]; C. difficile: 2.5% vs 1.1% [OR: 2.42, p-value: <0.001]). Multivariate analysis found transfer patients had an increased rate of HAIs (OR: 1.42; p-value: 0.009).

Conclusions:

There is an increased risk-adjusted rate of HAIs in transferred surgical patients as reflected in the NHSN metrics.  This phenomenon places a burden on regional centers that accept high-risk surgical transfers, in part because of the downstream effects of the CMS VBP and HAC reduction programs.