Effect of the Primary Nursing Model on Self-Care Skills of Hospitalized Older Patients with Multimorbidity: A Quasi-Experimental Study

<b>Background/Objective</b>: The global increase in life expectancy has led to a higher prevalence of multimorbidity among older patients, often requiring frequent and complex healthcare. Enhancing self-care skills during hospitalization is a key priority in promoting patient autonomy and improving outcomes. The objective of the study was to analyze the effect of the primary nursing model on the therapeutic self-care of older patients with multimorbidity during hospitalization. <b>Methods</b>: It was a quasi-experimental study conducted in two comparable medical-surgical units of a private hospital in Portugal. The intervention unit adopted the primary nursing model, while the control unit maintained standard nursing care. A convenience sample of older patients with multimorbidity was recruited (n = 206; intervention group = 106, control group = 100). Therapeutic self-care was measured using the Portuguese version of the Therapeutic Self-Care Scale at admission, discharge, and follow-up. Statistical analyses included independent samples <i>t</i>-tests to assess between-group differences. <b>Results</b>: At baseline, the intervention group had significantly lower self-care scores than the control group (t_(191.045) = -2.24; <i>p</i> = 0.026). However, between admission and follow-up, the intervention group showed significantly greater improvements in self-care scores compared with the control group (t_(187.55) = 2.68; <i>p</i> = 0.008). <b>Conclusions</b>: The primary nursing care model contributed to enhanced therapeutic self-care skills in older patients with multimorbidity during and after hospitalization. Nurse managers and clinical teams can consider the primary nursing model as an effective care organization strategy to foster self-care, promote patient-centered outcomes, and improve care continuity for older patients with complex needs. <b>Trial Registration</b>: ClinicalTrials.gov Identifier: NCT06702150 (Registered 12 November 2024).