Risk factors for the development of in-hospital complications in pluripathological patients

BACKGROUND AND OBJECTIVES Multimorbid patients (MP) represent a major challenge for health care systems due to their high prevalence, resource utilization, and poorer prognosis. In the hospital setting, they account for approximately one in four admissions. Although complications are common in this population, there is limited information regarding their type, frequency, impact, and associated factors. The aim of this study was to analyze in-hospital complications in multimorbid patients and their impact on health outcomes. MATERIALS AND METHODS Prospective observational study conducted between February 2022 and June 2023. Multimorbid patients aged ≥18 years admitted for any reason were included after providing informed consent; patients who died during hospitalization were excluded. Variables collected included sociodemographic characteristics, comorbidities, reason for admission, multimorbidity criteria, type and frequency of complications, frailty, length of stay, readmissions, and 30-day mortality. RESULTS A total of 535 patients were included (mean age 82.2 years); 334 (62.4%) developed at least one complication, accounting for 682 events. The most frequent were neurological (25.4%), digestive (19%), hematological (16%), and cardiovascular (15.7%). Patients with complications had a longer length of stay (11.6 vs. 7.3 days; p < 0.001) and higher 30-day mortality (10.5% vs. 4.5%; p < 0.05). In multivariate analysis, cognitive impairment, prostate disease, VIG-Frail index >0.4, anemia at admission, and hospital stay >6 days were associated with increased risk (AUC 0.713; 95% CI 0.669-0.756). CONCLUSIONS In-hospital complications are common among multimorbid patients and are associated with worse outcomes. Early identification of high-risk patients may enable preventive strategies and improve outcomes in this vulnerable population.