Table 5. Association analyses.

Analysis	N	P value
Association of 1L HHI and OS from initiation of 1L therapy	2,390	0.71*
Concordance with NCCN 1L Category 1 guidelines and OS from initiation of 1L therapy	2,912	0.45*
Concordance with any category NCCN 1L guideline and OS from initiation of 1L therapy	2,912	0.76*
Association of HHI in 1L therapy and concordance with NCCN 1L Category 1 guidelines	2,390	0.05**
Association of HHI in 1L therapy and concordance with any category NCCN 1L guidelines	2,390	0.001**

*, P values are from Cox proportional hazard regression model with covariates: age, gender, prior surgery (yes, no), disease site (gastric vs. GEJ), HER2 status (+, −, missing); **, P values are from generalized linear regression model with binomial distribution and logit link function with covariates: age, gender, prior surgery (yes, no), disease site (gastric vs. GEJ), HER2 status (+, −, missing). 1L, first-line; HHI, Herfindahl-Hirschman index; OS, overall survival; NCCN, National Comprehensive Cancer Network; GEJ, gastroesophageal junction.