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