The economics of complexity: internal medicine as the backbone of hospitals and guardian of health

Abstract

The Italian Servizio Sanitario Nazionale (SSN) and other universal healthcare systems face increasing pressure from aging, multimorbidity, malnutrition, obesity and the widespread consumption of ultra-processed foods (UPFS). Hospitals struggle not only with resources but with managing complexity. Medicine (IM) wards absorb most acute admissions and represent the hidden backbone of hospital functioning. Delayed discharges, hospital malnutrition, and obesity-related meta-inflammation illustrate systemic inefficiency and escalating costs. Evidence shows that internist-led interventions, including systematic nutritional screening, integrated obesity care, and the use of point-of-care ultrasound (POCUS), improve patient outcomes and hospital efficiency. The evolving role of IM requires combining holistic oversight with subspecialty competence (cardio-pulmonary, neuro-internal medicine, onco-internal medicine, gastro-metabolism, geriatrics, immunology, an infectious diseases). As guardians of health, internists must extend their role beyond acute care to prevention regulation of UPFs, and sustainable patient transitions. In conclusion, strengthening Internal Medicine is essential for preserving universal healthcare. Internists-generalist in vision, subspecialist in competence, ultrasonographer in practice-are both the economic and ethical backbone of hospitals and the guardians of public health.

Keywords: Acute Medical Units; Complexity management; Frailty; Health system sustainability; Internal medicine; Malnutrition; Multimorbidity; Obesity; Point-of-care ultrasound; Ultra-Processed foods.