Predicting postoperative morbidity and mortality in adult surgical patients: validation of the african surgical outcomes study surgical risk calculator at University Teaching Hospital of Kigali (CHUK)

Abstract

Background: Patients in Africa are twice as likely to die after surgery when compared to worldwide. There is still lack of appropriate risk assessment tools to predict postoperative morbidity and mortality at the continent. African Surgical Outcomes Study’s Surgical Risk Calculator (ASOS SRC) was shown to be more reliable in the African population. Thus, we aimed to assess the validation of the ASOS surgical risk calculator in a cohort of patients at University Teaching Hospital of Kigali (CHUK) Methods: Prospective observational cohort study of adult surgical patients at university teaching hospital of Kigali from 1st January to 1st March 2022, data were collected from patients’ anesthesia record sheets and medical files. Data from 350 patients were entered in Epidata version 3.1, then exported to Stata 13.0 for analysis. Patients were divided into 2 groups: Exposed (ASOS SRC score≥10) and Unexposed (ASOS SRC <10). Results: We recruited 350 patients, of whom the majority were aged 30-69 years (66.3%), Elective and emergent surgeries were nearly equal (51% versus 47.1%). Hypertension was the commonest comorbidity (12.5%) while non-communicable diseases were the commonest indication of surgery (40%). The overall postoperative morbidity rate was 13.7% versus 2.8% of mortality rate and 4.3% of patients required critical care admission. Of all the patients who died had an ASOS SRC score ≥10, nearly 80% of patients discharged had the score <10 and 60% of patients who remained in the hospital had the ASOS SRC score ≥10. patients with ASOS SRC scores ≥ 10 and more were 17 times more likely to develop post-operative complications than those with a score <10 (RR=17.12; 95% CI: 7.87-37.25; p<0.001). Our Multivariable logistic regression revealed ASOS SRC score, ASA class and surgery timing to be true predictors of postoperative morbidity and mortality. Conclusions: The study showed that ASOS Surgical Risk Calculator strongly predicts postoperative morbidity and mortality. Larger sample size studies are needed for results generalization and practice change.