Predictive Role of the C-Reactive Protein/Albumin Ratio in Identifying Complicated Acute Appendicitis: A Retrospective Study

Introduction: This study investigates the predictive value of the C-reactive protein/albumin ratio (CAR) in distinguishing complicated acute appendicitis (CAA) from non-complicated acute appendicitis (NCAA), aiming to enhance diagnostic accuracy and improve clinical decision-making. Methods: A retrospective analysis was conducted on patients diagnosed with acute appendicitis who underwent appendectomy between January 2016 and May 2020. Demographic, clinical, and laboratory data, including age, sex, white blood cell (WBC) count, neutrophil count (NE), lymphocyte count (LY), hemoglobin (Hb), mean platelet volume (MPV), platelet count (PLT), serum albumin (Alb) levels, and C-reactive protein (CRP) levels, were extracted from hospital records. Additionally, ASA scores and operative durations were recorded. Patients were classified into CAA and NCAA groups based on pathology reports and surgical notes. The CAR and other hematological parameters were compared between groups, and their diagnostic performance was evaluated. Results: The median CAR was significantly higher in the CAA group (5.53; range: 0.63–115.19) compared to the NCAA group (2.24; range: 0.59–97.50) (p < 0.001). The optimal CAR cut-off value for predicting CAA was 2.06, yielding a sensitivity of 72.61% and a specificity of 48.46%. The positive predictive value (PPV) was 46.20%, whereas the negative predictive value (NPV) was 74.40%. Furthermore, a CAR level exceeding 2.06 was associated with a 1.48-fold increased risk of complications (p = 0.001). Conclusion: Our findings suggest that CAR is a significant biomarker for predicting complicated acute appendicitis, offering valuable clinical insights for early risk stratification. When used in conjunction with other hematological parameters, CAR may enhance diagnostic accuracy and guide clinical decision-making, potentially reducing unnecessary interventions. Further large-scale, prospective studies are essential to validate the clinical utility of the CAR in the managem