C-Reactive protein and the CALLY index for predicting complicated appendicitis: a retrospective cohort study of 5,428 patients.
- 1University of Health Sciences, Kanuni Sultan Suleyman Training and Research Hospital, General Surgery Clinic, Istanbul, Turkey. [email protected].
- 2University of Health Sciences, Kanuni Sultan Suleyman Training and Research Hospital, General Surgery Clinic, Istanbul, Turkey.
- 3University of Health Sciences, Ankara Bilkent City Hospital, General Surgery Clinic, Ankara, Turkey.
Abstract
Background
Distinguishing complicated from uncomplicated appendicitis before surgery remains a critical yet unresolved clinical challenge. Delayed recognition of complicated appendicitis, particularly in cases of perforation or abscess formation, is associated with increased morbidity and mortality. Although various laboratory markers and inflammatory indices have been proposed as markers associated with disease severity, their relative diagnostic performance remains unclear. This study aimed to evaluate and compare the discriminatory performance of conventional laboratory parameters, leukocyte-derived indices, and composite biomarkers for complicated appendicitis.Methods
In this retrospective single-center cohort study, 5,428 patients who underwent emergency appendectomy between 2015 and 2025 were included. Patients were classified as uncomplicated or complicated appendicitis based on intraoperative findings. Preoperative laboratory parameters, including C-reactive protein, white blood cell count, total bilirubin, leukocyte-derived indices, and composite biomarkers such as the C-reactive protein-albumin-lymphocyte (CALLY) index and the hemoglobin-albumin-lymphocyte-platelet (HALP) index, were analyzed. Receiver operating characteristic analysis was used to assess diagnostic performance, and optimal cut-off values were determined using the Youden index. Multivariate logistic regression was performed to identify variables independently associated with complicated appendicitis.Results
Of the 5,428 patients, 707 (13.1%) had complicated appendicitis. C-reactive protein demonstrated the highest diagnostic accuracy (AUC: 0.781) and demonstrated the strongest independent association (OR: 5.29). Total bilirubin was also independently associated with complicated appendicitis (OR: 1.21). Leukocyte-derived indices showed limited discriminatory ability, with only the systemic immune-inflammation index remaining significant in multivariate analysis. The CALLY index demonstrated relatively strong discriminatory performance (AUC: 0.747), with lower values associated with increased disease severity.Conclusions
C-reactive protein remains the most robust laboratory marker for identifying complicated appendicitis. Composite biomarkers such as the CALLY index may provide additional value in risk stratification. These findings support the use of routinely available laboratory parameters in clinical risk assessment, although prospective validation is warranted.
Related
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BibTeX
@article{aydin2026creactive,
title = {{C-Reactive protein and the CALLY index for predicting complicated appendicitis: a retrospective cohort study of 5,428 patients.}},
author = {Mahmut Ozan Aydin and Erkan Somuncu and Cenk Ozkan and Zeynep Betul Yildiz and Kubilay Ozgur Oztutuncu and Ozgur Gangal and Beyhan Kilic and Serhan Yilmaz and Emre Bozdag},
journal = {BMC surgery},
year = {2026},
month = jul,
doi = {10.1186/s12893-026-04072-y},
url = {https://europepmc.org/article/MED/42894148},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - C-Reactive protein and the CALLY index for predicting complicated appendicitis: a retrospective cohort study of 5,428 patients.
AU - Mahmut Ozan Aydin
AU - Erkan Somuncu
AU - Cenk Ozkan
AU - Zeynep Betul Yildiz
AU - Kubilay Ozgur Oztutuncu
AU - Ozgur Gangal
AU - Beyhan Kilic
AU - Serhan Yilmaz
AU - Emre Bozdag
PY - 2026
DA - 2026/07/01
JO - BMC surgery
DO - 10.1186/s12893-026-04072-y
UR - https://europepmc.org/article/MED/42894148
AB - Background Distinguishing complicated from uncomplicated appendicitis before surgery remains a critical yet unresolved clinical challenge. Delayed recognition of complicated appendicitis, particularly in cases of perforation or abscess formation, is associated with increased morbidity and mortality. Although various laboratory markers and inflammatory indices have been proposed as markers associated with disease severity, their relative diagnostic performance remains unclear. This study aimed to evaluate and compare the discriminatory performance of conventional laboratory parameters, leukocyte-derived indices, and composite biomarkers for complicated appendicitis.Methods In this retrospective single-center cohort study, 5,428 patients who underwent emergency appendectomy between 2015 and 2025 were included. Patients were classified as uncomplicated or complicated appendicitis based on intraoperative findings. Preoperative laboratory parameters, including C-reactive protein, white blood cell count, total bilirubin, leukocyte-derived indices, and composite biomarkers such as the C-reactive protein-albumin-lymphocyte (CALLY) index and the hemoglobin-albumin-lymphocyte-platelet (HALP) index, were analyzed. Receiver operating characteristic analysis was used to assess diagnostic performance, and optimal cut-off values were determined using the Youden index. Multivariate logistic regression was performed to identify variables independently associated with complicated appendicitis.Results Of the 5,428 patients, 707 (13.1%) had complicated appendicitis. C-reactive protein demonstrated the highest diagnostic accuracy (AUC: 0.781) and demonstrated the strongest independent association (OR: 5.29). Total bilirubin was also independently associated with complicated appendicitis (OR: 1.21). Leukocyte-derived indices showed limited discriminatory ability, with only the systemic immune-inflammation index remaining significant in multivariate analysis. The CALLY index demonstrated relatively strong discriminatory performance (AUC: 0.747), with lower values associated with increased disease severity.Conclusions C-reactive protein remains the most robust laboratory marker for identifying complicated appendicitis. Composite biomarkers such as the CALLY index may provide additional value in risk stratification. These findings support the use of routinely available laboratory parameters in clinical risk assessment, although prospective validation is warranted.
SN - 1471-2482
ER -