There is no evidence that prolonged pre diagnostic symptomatic intervals (PSI) increases the risk of death in pediatric brain tumors. When investigating the role of time previous research had not controlled for confounding variables or measured the pretreatment interval (PTI). We use the term global delay interval (GDI) to describe the sum of PSI and PTI. The aim of this research was to evaluate whether there was a decrease in the probability of survival in children with brain tumors due to a prolonged PSI, PTI and GDI, using a multivariate survival analysis. We retrospective review 127 clinical records labeled with the diagnosis of CNS tumors attended at a specialized pediatric center in Mexico City from January 2008 to December 2012. Patients with PSI and GDI diagnosed between 3 and 6 months showed statistical lower probability of surviving that those with intervals <3 months even when adjusting for age, sex, localization and tumor grade. When stratified for the place of residency and adjusted for sex, age, localization, grade of tumor, type of surgery and coadjuvant therapy, a GDI between 3 and 6 months showed to be a risk factor for the overall survival of brain tumors compared with an interval < 3 months. When analyzing the interaction, high grade tumors are at more risk of dying when GDI was between 3 and 6 months compared to <3 months. Prolonged PSI and GDI showed to be a potential prognostic factor for survival in CNS tumors, especially in high grade tumors. Future prospective research should measure the PSI, PTI and GDI and adjust for covariates in order to properly infer the effect of time in pediatric brain tumors.

没有证据表明延长诊断前症状间隔（PSI）会增加儿童脑肿瘤的死亡风险。在调查时间的作用时，之前的研究没有控制混杂变量或测量预处理间隔（PTI）。我们使用术语全局延迟间隔 (GDI) 来描述 PSI 和 PTI 之和。本研究的目的是通过多变量生存分析来评估脑肿瘤儿童的生存概率是否会因 PSI、PTI 和 GDI 延长而降低。我们回顾性审查了 2008 年 1 月至 2012 年 12 月期间在墨西哥城一家专门儿科中心就诊的 127 份标有中枢神经系统肿瘤诊断的临床记录。在 3 至 6 个月之间诊断出的 PSI 和 GDI 患者的生存概率在统计上低于间隔期患者即使调整了年龄、性别、部位和肿瘤分级，也小于 3 个月。当根据居住地进行分层并根据性别、年龄、部位、肿瘤分级、手术类型和辅助治疗进行调整时，与未接受治疗的患者相比，3 至 6 个月之间的 GDI 被证明是脑肿瘤总体生存的危险因素。间隔 < 3 个月。在分析相互作用时，与 <3 个月相比，当 GDI 在 3 至 6 个月之间时，高级别肿瘤死亡的风险更大。延长的 PSI 和 GDI 被证明是中枢神经系统肿瘤（尤其是高级别肿瘤）生存的潜在预后因素。未来的前瞻性研究应该测量 PSI、PTI 和 GDI 并调整协变量，以便正确推断时间对儿童脑肿瘤的影响。