Evaluation of POSSUM and P-POSSUM as predictors of mortality and morbidity in patients undergoing laparotomy at a referral hospital in Nairobi, Kenya

Background The Physiological and Operative Severity Score for enUmeration of Morbidity and Mortality (POSSUM) and its Portsmouth modification (P-POSSUM) were developed for comparative audit in surgical patients. This study evaluated applicability of these systems in estimating mortality and morbidity risks in a cohort of patients undergoing laparotomy at the national referral hospital in Nairobi, Kenya. Methods Data of 166 patients undergoing laparotomy was subjected to POSSUM and P-POSSUM scoring systems and analyzed using linear and exponential methods. The discrimination power of POSSUM and P-POSSUM as predictors of surgical outcome was measured using the receiver–operating characteristic (ROC) curve. Results The overall observed to expected (O:E) ratio using linear analysis was 0.29:1 (POSSUM) and 0.67:1 (P-POSSUM) while exponential analysis gave an O:E of 0.2:1 (POSSUM) and 0.4:1 (P-POSSUM). The predicted morbidity using POSSUM was 1.09:1 (linear analysis) and 1:1 (exponential analysis). Hosmer–Lemeshow analysis did not show a significant lack of fit with the observed mortality when applied to POSSUM and P-POSSUM. The area under ROC curve was 0.74 (POSSUM) and 0.78 (P-POSSUM). Conclusion Our results support the suitability of P-POSSUM and POSSUM scoring systems to stratify morbidity and mortality risk in our study population

Textual Complexity and Discourse Structure in Computer-Supported Collaborative Learning

International audienceComputer-Supported Collaborative Learning (CSCL) technologies play an increasing role simultaneously with the appearance of the Social Web. The polyphonic analysis method based on Bakhtin’s dialogical model reflects the multi-voiced nature of a CSCL conversation and the related learning processes. We propose the extension of the model and the previous applications of the polyphonic method to both collaborative CSCL chats and individual metacognitive essays performed by the same learners. The model allows a tight correlation between collaboration and textual complexity, all integrated in an implemented system, which uses Natural Language Processing techniques