Alexis Serna-Menor, Juan Pablo Hervás-Pérez, José Antonio Guerra-Guirao, Cibeles Serna-Menor, Gema Mata-González, Andrés García-Notario, María Arnazazu Sánchez-Calabuig, Ivan Herrera-Peco
Humanized healthcare depends on professionals' capacity to communicate empathically, respond compassionately, and establish therapeutic relationships. This globally focused systematic review aimed to synthesize comparative evidence on educational and professional development interventions designed to strengthen humanistic and relational practice among patient-facing healthcare professionals across international healthcare contexts. MEDLINE via PubMed, Scopus, Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Comparative intervention studies involving practicing healthcare professionals were included. Findings were synthesized narratively by relational domain and assessment source. Risk of bias was evaluated using the revised Cochrane risk-of-bias tool for randomized trials (RoB 2), its extension for cluster-randomized trials, and the Risk Of Bias In Non-randomized Studies of Interventions Version 2 (ROBINS-I V2). Thirty-five reports representing 33 independent studies were included. Reports addressed clinical empathy and emotional responsiveness (n = 22); compassion, caring, and humanistic practice (n = 7); and trust, rapport, and therapeutic relationships (n = 6). Favorable effects were most consistent for proximal professional outcomes, including self-reported empathy, compassion, caring competence, confidence, and self-efficacy. Several studies also reported improvements in specific observed communication behaviors. However, patient- and family-reported outcomes were less frequently assessed and showed less consistent favorable between-group differences. Longer-term maintenance was also uncertain. Most individually randomized trials raised some concerns about risk of bias (13/19), while the two cluster-randomized trials were judged as having some concerns and high risk, respectively; all 12 nonrandomized comparative studies were at serious risk of bias. Educational interventions may strengthen selected relational competencies, but evidence of sustained transfer to routine practice, patient experience, trust, and therapeutic alliance remains limited and heterogeneous.