Participants in this arm received a comprehensive nursing intervention based on the Integrated Theory of Health Behavior Change (ITHBC), in addition to routine care. The intervention consisted of five phases: personalized assessment, knowledge and belief reinforcement, skill and competency development, goal setting and follow-up, and social support promotion, delivered over a 3-month period.

Participants in this arm received routine care, including admission education, standardized in-hospital health education, and either outpatient or telephone follow-up once monthly for 3 months post-discharge.

A 3-month comprehensive nursing program based on the Integrated Theory of Health Behavior Change (ITHBC), consisting of five phases: (1) personalized assessment of frailty, nutritional status, physical activity, social support, and self-management capabilities; (2) knowledge and belief reinforcement through video-based and handbook-based education; (3) skill and competency development in nutrition management, multicomponent exercise training, and medication guidance; (4) goal setting and follow-up with individualized diet and exercise plans, biweekly visits in the first month and monthly visits thereafter; and (5) social support promotion involving healthcare professionals, family members, and peer support groups.

The Fried Frailty Phenotype Scale was developed by Fried et al. in 2001 and is recognized as the most widely used frailty assessment tool in the fields of gerontology and nephrology. This scale includes five components: unintentional weight loss, exhaustion, reduced grip strength, slow walking speed, and decreased physical activity. One point is assigned for each criterion that is met, yielding a total score that ranges from 0 to 5. A score of 0 indicates absence of frailty; scores of 1-2 suggest pre-frailty; and scores of 3 or more indicate frailty. The Cronbach's α coefficient for this scale was reported as 0.868.

The Chronic Kidney Disease Self-Management Scale (CKD-SM), which was developed by Yu P. and colleagues, evaluates the self-management behavior level of patients undergoing home-based peritoneal dialysis. This scale contains 31 items, which cover four domains: dietary management (12 items), treatment management (9 items), physical activity management (5 items), and psychosocial management (5 items). Each item was scored on a 4-point Likert scale, with response options ranging from "never" to "always" and corresponding scores ranging from 1 to 4. The total score ranges from 31 to 124, with higher scores indicating stronger self-management abilities. The overall Cronbach's α coefficient of this scale was reported as 0.902, and the test-retest reliability was reported as 0.898.

The Nutritional Risk Screening Tool (NRS-2002), which was developed by Kondrup and colleagues, is an evidence-based screening tool for nutritional risk. The total score is calculated as the sum of three components: a disease severity score, a nutritional status impairment score, and an age score. Both the disease severity score and the nutritional status impairment score range from 0 to 3 points, with 1 additional point being added for patients aged ≥ 70 years. The total score ranges from 0 to 7 points, and a score of ≥ 3 indicates the presence of nutritional risk. The Cronbach's α coefficient for this scale was reported as 0.760, and the criterion validity was reported as 0.670.