(1) Background: Iliopsoas abscess (IPA) is usually overlooked due to its nonspecific symptoms and signs. The resulting delayed diagnosis and treatment can increase morbidity and mortality. The purpose of the present study was to identify the risk factors for the unfavorable outcomes associated with IPA. (2) Methods: We included patients who presented to the emergency department and were diagnosed with IPA. The primary outcome was in-hospital mortality. Variables were compared, and the associated factors were examined with Cox proportional hazards model. (3) Results: Of the 176 patients enrolled, IPA was of primary origin in 50 patients (28.4%) and of secondary origin in 126 (71.6%). Skeletal origin was the most common source of secondary IPA (n = 92, 52.3%). The most common pathogens were Gram-positive cocci. Eighty-eight (50%) patients underwent percutaneous drainage, 32 (18.2%) patients underwent surgical debridement, and 56 (31.8%) patients received antibiotics. Multivariate analyses indicated that age > 65 (year) (HR = 5.12; CI 1.03-25.53; p = 0.046), congestive heart failure (HR = 5.13; CI 1.29-20.45; p = 0.021), and platelet < 150 (103/μL) (HR = 9.26; CI 2.59-33.09; p = 0.001) were significant independent predictors of in-hospital mortality in Model A, while the predictors in Model B included age > 65 (year) (HR = 5.12; CI 1.03-25.53; p = 0.046) and septic shock (HR = 61.90; CI 7.37-519.46; p < 0.001). (4) Conclusions: IPA is a medical emergency. Our study reported that patients with advanced age, congestive heart failure, thrombocytopenia, or septic shock had a significantly higher risk of mortality, and the recognition of the associated factors may aid in risk stratification and the determination of the optimal treatment plan for IPA patients.
Keywords: iliopsoas abscess; in-hospital mortality; length of hospital stay (LOS).