This study evaluates a co-designed nutritional training program for oncology nurses in Vietnam. The aim is to improve nurses' knowledge, confidence, and clinical practice in providing nutritional support for patients with cancer experiencing treatment-related symptoms.

The study used a single-group pre-post intervention design. Oncology nurses participated in a structured training program that included theoretical sessions and supervised clinical practice. After training, nurses delivered nutritional support to patients during routine care.

The study assessed changes in nurses' knowledge, self-confidence, and practice performance before and after the intervention. In addition, the acceptability of the program was evaluated from both nurses and patients who received the nutritional support.

This study provides preliminary evidence on the feasibility and potential effectiveness of a nurse-led nutritional training program and supports the integration of structured nutritional care into routine oncology practice.

This study aimed to evaluate the effectiveness and acceptability of a co-designed nutritional training program for oncology nurses in Vietnam. The intervention was developed using a co-design approach involving patients, nurses, dietitians, and other healthcare professionals to ensure relevance, feasibility, and cultural appropriateness.

The study employed a single-group pre-post intervention design and was conducted at a tertiary teaching hospital in Vietnam. A convenience sample of oncology nurses participated in the training program. The intervention consisted of a three-day training workshop, including theoretical education on cancer-related nutrition and supervised clinical practice sessions. During the clinical component, nurses applied their knowledge in real patient interactions under supervision, using a structured checklist to guide nutritional assessment and counselling.

Following the training, nurses delivered nutritional support to patients with cancer experiencing treatment-related symptoms, including gastrointestinal and oral complications affecting dietary intake. The intervention focused on symptom-based dietary management strategies, practical counselling techniques, and patient-centered communication.

The primary outcomes were changes in nurses' knowledge and self-confidence in providing nutritional support, measured before and after the training program. Secondary outcomes included nurses' clinical practice performance, assessed using a standardized observational checklist, and the acceptability of the intervention among both nurses and patients.

Patient participants received nutritional support as part of routine care delivered by trained nurses. Acceptability was assessed one week after the intervention using a structured questionnaire to evaluate perceived usefulness, clarity, and applicability of the dietary guidance.

This study provides preliminary evidence on the feasibility, safety, and effectiveness of a nurse-led, co-designed nutritional training program. The findings support the role of oncology nurses in delivering structured nutritional care and highlight the potential for integrating such interventions into routine clinical practice, particularly in resource-constrained settings.

Inclusion Criteria:

• Registered oncology nurses involved in direct patient care
• Working in oncology departments at the study site
• Willing to participate in the training program and evaluation

Exclusion Criteria:

• Nurses not involved in direct patient care
• Nurses unable to attend the full training program
• Nurses who decline to participate

Individual participant data (IPD) sharing has not yet been determined. Data sharing will be considered in accordance with institutional policies, ethical approvals, and participant confidentiality requirements.