a Cohorts were matched 1:1 on age,

a Cohorts were matched 1:1 on age, race, sex, time from the index admission until the last date in the study file, California region of patient’s residence, Charlson comorbidity index score at index admission, and number of hospital admissions following index admission until readmission with schizophrenia (the outcome measure) or study end, whichever occurred first.
b Covariate adjustment on matching variables in the Cox models is not necessary if groups are balanced across covariates (26); all matched groups in this table showed balance, measured according to standardized differences (24) across all continuous variables as well as all levels of categorical variables used as covariates in the propensity score matching process.
c This column represents the total combined number of individuals across both matched cohorts; each cohort had a sample size of one-half of the number listed in this column.
d The numbers before and after the colon represent the number of schizophrenia events in the target cohort and in the reference group, respectively.