Evaluation of POSSUM scoring systems in predicting postoperative morbidity and mortality in indian patients operated for esophageal cancer

• Main Authors: Priya Ramakrishnan, Manisa Pattanayak, Anshika Arora, Ankit Singh, Veena Asthana, Sunil Saini
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2020-01-01
• Series: Bali Journal of Anesthesiology
• Subjects: esophageal cancer; mortality; morbidity; possum score; receiver operating characteristic curve; scoring systems
• Online Access: http://www.bjoaonline.com/article.asp?issn=2549-2276;year=2020;volume=4;issue=2;spage=53;epage=58;aulast=Ramakrishnan

Background: Surgical treatment for esophageal cancer is a high-risk procedure. Prediction of postoperative adverse events could aid in the stratification of patients, thus improving outcomes as well as achieving optimal use of resources. The Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM) is a prediction model that utilizes both physiological and surgical parameters to assess risk. This study evaluates the effectiveness of POSSUM, Portsmouth-POSSUM (P-POSSUM), and esophagogastric-POSSUM (O-POSSUM) scoring systems in predicting postoperative morbidity and mortality in Indian patients operated for esophageal cancers. Patients and Methods: It is a retrospective study conducted in a tertiary care teaching hospital with data collected from esophagectomies performed from January 2015 to January 2019. The calibration and discriminative abilities of the scores to predict 30-day morbidity and mortality were analyzed using the Hosmer–Lemeshow test, observed to predicted ratios (observed/expected [O/E]), and the receiver operating characteristic curve tests. Results: A total of sixty patients were included. The 30-day mortality and morbidity were 6.67% (4/60) and 46.66% (28/60), respectively. POSSUM morbidity showed proper calibration and discrimination (O/E: 0.86) with a modest predictive ability (area under the curve [AUC]: 0.701). While analyzing mortality, though all scores displayed good calibration, O-POSSUM displayed superior predictive ability (O/E: 1.02). The POSSUM score overpredicted mortality by nearly twice (O/E: 0.52), whereas P-POSSUM underpredicted it (O/E: 1.71). All scores showed moderate discrimination with P-POSSUM outperforming other tests (AUC: 0.825). Conclusions: The POSSUM scoring system was useful in predicting morbidity risk following esophageal resection for cancer, with O-POSSUM more accurate for mortality prediction in this group of patients.