title: [Statistical methods for comparing survival rates at a fixed time point].
abstract: Comparison of survival curves between two groups is an important part of disease prognosis study. Log-rank test is commonly used, but when the two curves' later intersecting opening is too large, the proportion of assumptions is not established, thus the Log-rank test is ineffective. We introduces five statistical tests to compare two survival curves at a fixed time points: classic method, logarithmic transformation, cloglog transformation, arcsine transformation and logit transformation. Through the study we found that if the overall survival curves are difficult to compare between groups tested with Log-rank test method or Two-stage test method, the fixed time point test can effectively determine whether there was significant difference in survival rate at a fixed time point. Among the five fixed time point tests, cloglog transformation could give more precise result.
authors.affiliation: The Department of Biostatistics, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Jinbao
authors.initials: J
authors.lastname: Chen
authors.affiliation: The Department of Biostatistics, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Libin
authors.initials: L
authors.lastname: Qiu
authors.affiliation: The Department of Biostatistics, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Beiqi
authors.initials: B
authors.lastname: Wang
authors.affiliation: The Department of Biostatistics, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zeng
authors.affiliation: The Department of Biostatistics, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China. Email: zchen@smu.edu.cn.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chen
mesh_terms: D004812:Epidemiologic Methods; D011379:Prognosis; D015996:Survival Rate