BACKGROUND: Lung cancer is a leading cause of global morbidity and mortality, severely affecting patients' quality of life (QoL). Understanding the factors associated with QoL in these patients is crucial for improving treatment and care. This study aimed to assess QoL among lung cancer patients and identify the factors influencing it. METHODS: This cross-sectional analytic study included 130 patients diagnosed with lung cancer at a tertiary facility in Northeastern Thailand. QoL was evaluated using the FACT-L interview, covering subscales such as physical, social/family, emotional, and functional well-being, as well as a lung cancer subscale, and the FACT-L Trial Outcome Index (TOI) and FACT-G. Descriptive statistics and multiple logistic regression were used for data analysis. RESULTS: The majority of subjects had low overall QoL (52.31%
Mean ± SD: 45.24 ± 11.33), low FACT-L TOI (83.08%
21.05 ± 9.21), and low FACT-G (57.69%
35.72 ± 8.70). Subscale analysis revealed low levels of physical well-being (85.38%
6.56 ± 3.54), emotional well-being (85.38%
6.15 ± 3.67), and functional well-being (96.15%
4.97 ± 3.82). However, about half of the subjects reported moderate social/family well-being (50.77%
18.04 ± 4.17) and lung cancer subscale scores (56.15%
9.51 ± 4.31). Multivariate analysis identified factors significantly associated with higher QoL, including age (AOR = 1.05, 95% CI: 1.01-1.10), absence of comorbidities (AOR = 3.95, 95% CI: 1.60-9.74), and absence of lymph node invasion (AOR = 4.42, 95% CI: 1.26-15.56). Conversely, sleep problems (AOR = 0.26, 95% CI: 0.08-0.81), local metastasis (AOR = 0.25, 95% CI: 0.09-0.72), and undergoing radiotherapy (AOR = 0.25, 95% CI: 0.07-0.98) were associated with lower QoL. CONCLUSIONS: These findings suggest that lung cancer patients with sleep problems, local metastasis, or undergoing radiotherapy should receive intensive palliative care to improve their QoL during the end of life stage.