Table 2. Effect of temozolomide added to radiotherapy on hazard ratios for overall survival.

Overall survival defined as starting 60 days following diagnosis, for equal period of treatment ascertainment TMZ temozolomide, RT radiotherapy, SEER surveillance, epidemiology, and end results, PS propensity score, IPTW inverse probability of treatment weighting

^aModel was adjusted for age, sex, marital status, race, median income in the census tract of residence, Deyo comorbidity score [13], tumor location, tumor size, surveillance, epidemiology, and end results (SEER) region, hospital discharge location, and extent of resection

^bPropensity of receiving temozolomide with radiotherapy was estimated using a multivariable regression model that included age, sex, marital status, race, median income in the census tract of residence, Deyo comorbidity score, tumor location, tumor size, SEER region, hospital discharge location, and extent of resection

^cFor subgroup and sensitivity analyses, IPTW modeling was used, adjusting for same baseline covariables listed above in the multivariable adjusted model, with removal of the specific covariable being analyzed

^dMatches were obtained to the RT 1995–2009 treatment group with replacement