Supplementary Figure S4 from Prediagnostic prescription antibiotics use and survival in colorectal cancer patients: A Swedish national register-based study

Supplementary Figure S4: Antibiotics use in relation to survival outcomes in stage I-III colorectal cancer (crude and completecase multivariable analyses). (A) Antibiotics use in relation to overall survival. (B) Antibiotics use in relation to cancer-specific survival. Prediagnostic antibiotics use was categorized as no use, any use, low use (1-10 days), moderate use (11-60 days), high use (61-180 days) and very high use (>180 days), based on defined daily doses. Antibiotics use during one year before colorectal cancer diagnosis was excluded to account for potential use due to undiagnosed but clinically manifest colorectal cancer. CI = confidence interval; HR = Hazard Ratio. Model 0 is crude or univariable Cox analysis. Model 1 is a Cox proportional hazard model including main demographic and socioeconomic factors (age and calendar year of diagnosis and prediagnostic Charlson comorbidity index as continuous variables, and sex, place of birth, county of residence, marital status, level of education, income status and family history of colorectal cancer as categorical variables). Model 2 includes tumour sites and tumour stage in addition to the covariates in model 1. Model 3 includes therapy-related variables such as operation type, preoperative chemotherapy (yes/no) and preoperative radiotherapy (yes/no) in addition to covariates in model 2. Variable definitions and categorization for the covariates in models 1-3 are as presented in Table 1. For each multivariable model, variables violating the proportional hazard assumption were controlled for by stratification in the respective models. They were age at diagnosis (