Osmani Freshteh, Hajizadeh Ebrahim, Rasekhi Aliakbar
Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
J Res Health Sci. 2018 Dec 29;18(4):e00433.
Recurrent event data are often encountered in biomedical research, for example, recurrent infections or recurrent hospitalizations for patients after renal transplant. In many studies, there are more than one type of events of interest. We aimed to identify the association between two types of events using multivariate joint modeling and then apply this statistical method in the clinical data set.
A retrospective cohort study.
Overall, 342 subjects with breast cancer whose records were registered for follow-up in a Cancer Research Center at Shohadaye Tajrish Hospital, Tehran, Iran from 2006 to 2015 were investigated. These patients were monitored for at least 6 months after diagnosis and their latest status were recorded. Joint frailty model was used for modeling the relationship between two types of recurrences with Frailty package in R software.
When the terminal event was considered as death, three-year and five-year survival rates for the patients were 0.79 and 0.68, respectively. Given the results obtained from a fitted joint frailty model, the risk of multiple recurrences (local and metastases) increased for the patients with tumor grades greater than I.
With regard to the significant variance of the frailty component of the metastases event, it can be inferred that patients with the same predictive variables are prone to different levels of metastases risk and, on the other hand, given the low frequency of types of recurrences, caution should be exercised when considering the obtained results.
复发事件数据在生物医学研究中经常遇到，例如肾移植后患者的反复感染或反复住院。在许多研究中，存在不止一种感兴趣的事件类型。我们旨在使用多变量联合建模确定两种事件类型之间的关联，然后将这种统计方法应用于临床数据集。
一项回顾性队列研究。
总体上，对2006年至2015年在伊朗德黑兰塔吉里什医院肖哈代癌症研究中心登记随访记录的342例乳腺癌患者进行了调查。这些患者在诊断后至少监测6个月，并记录其最新状态。使用R软件中的脆弱性包中的联合脆弱模型对两种复发类型之间的关系进行建模。
当将终末事件视为死亡时，患者的三年和五年生存率分别为0.79和0.68。根据拟合的联合脆弱模型获得的结果，肿瘤分级大于I级的患者发生多次复发（局部和转移）的风险增加。
关于转移事件脆弱性成分的显著差异，可以推断出具有相同预测变量的患者易患不同水平的转移风险，另一方面，鉴于复发类型的频率较低，在考虑所得结果时应谨慎。
