A Retrospective Risk Analysis of Factors Associated with Prolonged Hospitalization in Adult Patients Undergoing Non-surgical Treatment for Appendiceal Abscess

Background: The aim of the present study was to investigate risk factors and predictive factors for prolonged hospitalization in adults undergoing non-surgical treatment for appendiceal abscess. Patients and Methods: A retrospective study was conducted of consecutive patients who underwent treatment following a diagnosis of appendicitis in a single institution. Between January 2008 and May 2019, 756 adult patients who were diagnosed with acute appendicitis, 101 of these patients (13.4%) had an appendiceal abscess and were treated as inpatients. The treatments of these patients were as follows: non-surgical treatment alone (n=45), emergency operation (n=50) and conversion to emergency operation due to failure of the initial conservative therapy (n=6). The present study analyzed the 45 patients managed with non-surgical treatment alone. The patients were divided, based on the median length of the hospital stay (nine day), into the shorter hospital stay and longer hospital stay groups. The risk factors and predictive factors for prolonged hospitalization were examined in the two groups. Results: Twenty-four patients were classified into the shorter hospital stay group and 21 were classified into the longer hospital stay group. A univariate analysis demonstrated that the body temperature on post-admission days 2 (P=0.012) and 3 (P=0.008), were significantly associated with the length of hospital stay. A multivariate logistic regression analysis using that the body temperature on post-admission day 3 tended to be associated with prolonged hospitalization (odds ratio=8.574, 95% confidence interval=0.973-75.525; P=0.053). The cut-off value of the body temperature on day 3, determined by an ROC curve analysis, was 37.05°C. This cut-off value showed 66.7% accuracy, 57.1% sensitivity and 75.0% specificity. Conclusion: The body temperature on post-admission day 3 might be a potential risk factor and predictive marker for prolonged hospitalization in patients who receive non-surgical treatment for appendiceal abscess.