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. Frontier in Medical and Health Research, [S. l.], v. 4, n. 3, p. 748–759, 2026. Disponível em: https://fmhr.net/index.php/fmhr/article/view/2503.. Acesso em: 8 nov. 2026.