Statistical analysis
Descriptive statistics was used to summarize baseline characteristics. Fisher’s exact test for categorical data and a Mann–Whitney U test for continuous variables were used to assess between-group differences at the baseline or AE incidence during EGFR-TKI treatment. Progression-free survival (PFS) was defined as the time from EGFR-TKI treatment initiation to the first documented disease progression or death, while overall survival (OS) was defined as the time from EGFR-TKI treatment initiation to the date of death regardless of the cause of death. Patients without disease progression or those who died by the time of analysis were censored at the date of last contact. Survival distributions were estimated using the Kaplan–Meier method, and between-group differences were compared using the log-rank test. The potential predictors of survival were explored using Cox regression. Characteristics with P < 0.05 after univariate analysis were included in multivariate analysis. Cluster analysis was conducted to identify factors affecting PIM use. CCI scores, number of organs involved in metastasis, the ECOG-PS, and GRIm-Score were standardized on their ranges and used in cluster analysis. In addition, hierarchical cluster analysis with Ward’s method was performed with squared Euclidean distances. All P -values were two-sided, and P < 0.05 was considered statistically significant. All statistical analyses were performed using R 3.6.3.
Results