IMPACT OF PREOPERATIVE COMORBIDITIES ON POSTOPERATIVE MORBIDITY AND MORTALITY IN ADULTS UNDERGOING MAJOR ABDOMINAL SURGERY: A SYSTEMATIC REVIEW AND META-ANALYSIS OF DIABETES MELLITUS, HYPERTENSION, CHRONIC KIDNEY DISEASE, AND OBESITY. FMHR [Internet]. 2026 Mar. 19 [cited 2026 Nov. 8];4(3):748-59. Available from: https://fmhr.net/index.php/fmhr/article/view/2503