The effect of comorbidity on 28-day perioperative mortality rate among non-cardiac surgical patients in Northwest Ethiopia: a prospective cohort study using propensity score matching

Abstract

Background: Non-communicable diseases account for nearly three-fourths of global deaths impacting public health and development. Coexisting diseases can complicate the management of surgical diseases, increasing the risk of perioperative mortality. Despite this, few studies have examined the burden of comorbidities among surgical patients and their effect on perioperative outcomes in low-income countries. In this study, we assessed the impact of comorbidity burden on 28-day perioperative mortality using a prospective data set. Methods: This was a facility-based prospective cohort study. Adult patients aged ≥ 18 who underwent non-cardiac surgery were included. Patients were followed for 28 days following surgery. Perioperative data were collected using an electronic data collection system from June 01, 2019, to June 30, 2021, at Tibebe Ghion Specialized Hospital, Northwest, Ethiopia. A propensity score-matched analysis was employed to assess the effect of comorbidity on the 28-day perioperative mortality rate. Results: Of the 3030 patients included in this study, 715 (23.59%) had at least one comorbidity. Based on the prevalence rate, the top four comorbid conditions observed were hypertension (0.050), cancer (0.036), diabetes mellitus (0.021), and human immunodeficiency virus (0.021). The 28-day perioperative mortality rate was shown to be significantly higher among patients with comorbidity, where 45 (6.29%) of the 715 patients with comorbidity died compared to 49 (2.12%) of the 2315 patients with no comorbidity (p-value < 0.0001). After propensity score matching potential confounders, patients who have comorbidity had a 2.52% (average treatment effect on treated (ATT) = 0.0252) higher risk of perioperative death at 28 days after surgery compared with patients who did not have comorbidity. Conclusion: This study found a moderate prevalence of comorbid illnesses among non-cardiac surgical patients, with comorbidity increasing the risk of 28-day perioperative mortality. Preoperative screening and optimization are highly recommended for patients with comorbid illness to decrease perioperative mortality rate.