Patients in the routine group were given routine care, including disease monitoring, medication care, diet and nutrition guidance, basic life care, routine health education on admission and discharge, symptomatic treatment of patients' discomfort symptoms, telephone follow-up twice a week to understand the patient's condition, and no systematic and personalized SM nursing intervention.

On the basis of routine nursing, implementation of systematic SM nursing intervention for 8 weeks, the specific content is as follows: (1) The intervention group was established. (2) Baseline assessment and file establishment (within 24 hours of admission).(3) Implementation of core intervention (1st to 8th week).

Patients in the routine group were given routine care, including disease monitoring, medication care, diet and nutrition guidance, basic life care, routine health education on admission and discharge, symptomatic treatment of patients' discomfort symptoms, telephone follow-up twice a week to understand the patient's condition, and no systematic and personalized SM nursing intervention.

The Functional Assessment of Cancer Therapy-Lung (FACT-L) scale will be used to assess changes in quality of life in patients with advanced lung cancer. The scale consists of 36 items across five domains: physical health status, social and family conditions, emotional well-being, functional capability, and lung cancer-specific supplementary concerns. Each item is scored on a 0-4 Likert scale, with total scores ranging from 0 to 144. Higher scores indicate better quality of life. The scale has demonstrated good reliability and validity in Chinese populations (Cronbach's α = 0.88-0.92).

The SUPPH scale will be used to assess changes in disease self-management efficacy. The scale includes 28 items across three dimensions: Positive Attitude, Self-Applied Stress Reduction, and Independent Decision-Making. Each item is scored on a 1-5 Likert scale, with total scores ranging from 28 to 140. Higher scores indicate greater self-management efficacy. The Chinese version has excellent reliability (Cronbach's α = 0.96 for the total scale).

This outcome will examine whether self-management efficacy (SUPPH score) mediates the relationship between the symptom management nursing intervention (group assignment) and quality of life (FACT-L score). The mediating effect will be analyzed using the PROCESS macro with bootstrap resampling (5,000 iterations). Indirect effect, direct effect, and total effect will be calculated with 95% confidence intervals. An effect is considered significant if the 95% CI does not include zero.