Table 2. Cox proportional hazard model of overall survival by use of intrathecal chemotherapy.

	Univariate analysis			Multivariate analysis*
	HR	95%CI	p value	HR	95%CI	p value
All patients	1.29	0.87–1.91	0.21	0.71	0.41–1.22	0.21
Patients treated with IT and systemic therapy	N/A		N/A	0.86	0.36–2.07	0.743
Patients not treated with IT and treated with systemic therapy	N/A		N/A	0.38	0.20–0.70	0.002

* Adjusted with propensity scores (variable included in the model: age, performance status, molecular type, central nervous system metastasis, visceral metastasis, previous lines of therapy, systemic therapy and radiotherapy and interaction term between intrathecal chemotherapy and systemic therapy). To calculate the hazard ratios, the reference category consisted of patients not treatment with systemic therapy or intrathecal chemotherapy.

HR: hazard ratios; 95%CI: 95% confidence intervals; IT: intrathecal chemotherapy.