Does Comorbidity Index Predict OPAT Readmission?

Abstract

Objectives – To determine if the Charlson Comorbidity Index (CCI) is an accurate predictor of unplanned readmissions for patients using Outpatient Parenteral Antimicrobial Therapy (OPAT) services.

Methods – Retrospective analysis of patients > 16 years of age who had received OPAT at Lancashire Teaching Hospitals between 2019 and 2021. The number of unplanned hospitalisations was measured and categorised as OPAT related or non-OPAT related. The CCI for each patient group was calculated using an online tool and multivariate analysis was used for each group of readmitted patients.

Results – The cohort consisted of 741 patients. Unplanned readmission was seen in 112 patients (15.1%). The mean CCI score for patients with OPAT related readmissions was 4.22, 0.92 higher than the mean for patients who were not readmitted (3.30). The mean CCI score for patients with non-OPAT related readmissions was higher still, 4.89. Multivariate analysis showed that increased CCI, age, male gender and home location compared with clinic were associated with increased odds of readmission, although these effects did not meet statistical significance.

Conclusions – These results suggest that a higher CCI score is associated with a non-statistically significant increased risk of unplanned hospitalisation. We concluded that the CCI may therefore be used in future decision making regarding the acceptance of patients to OPAT and requires further investigation.