ITP survival analysis:   4-OH-a-phenyl-N-tert-butyl nitrone

Intervention:   4-OH-a-phenyl-N-tert-butyl nitrone     anti-oxidant
Trial code: 4-OH-PBN Dose: 315 ppm initiated at age: 4 mo Sex: both Cohort: C2004
Results are based on the use of pooled factor(s) that is/are stratified within the survival analysis model.

All test sites combined – female
4-OH-PBN effect on survival, females, test site = All
Log-rank test chisq = 0.4712 p = 0.4924
Wang-Allison test odds ratio = 1.0587 p = 0.8624
Quantiles 4-OH-PBN Control % difference
25% died before day: 741 739 0 %
Median lifespan (days) 850 888 -4 %
75% died before day: 970 988 -2 %
90% died before day: 1077 1072 0 %
Max lifespan observed (days) 1206 1212
Number of mice at start 133 271
Animal censor events are denoted by + marks in the plot
All test sites combined – male
4-OH-PBN effect on survival, males, test site = All
Log-rank test chisq = 0.6507 p = 0.4199
Wang-Allison test odds ratio = 1.0341 p = 1.0
Quantiles 4-OH-PBN Control % difference
25% died before day: 617 612 +1 %
Median lifespan (days) 808 784 +3 %
75% died before day: 939 912 +3 %
90% died before day: 1037 1048 -1 %
Max lifespan observed (days) 1332 1305
Number of mice at start 165 350
Animal censor events are denoted by + marks in the plot


By individual test site:

TJL – female
TJL – female      
4-OH-PBN effect on survival, females, test site = TJL
Log-rank test chisq = 0.1638 p = 0.6857
Wang-Allison test odds ratio = 1.0718 p = 1.0
Quantiles 4-OH-PBN Control % difference
25% died before day: 729 738 -1 %
Median lifespan (days) 875 858 +2 %
75% died before day: 976 969 +1 %
90% died before day: 1055 1050 0 %
Max lifespan observed (days) 1119 1212
Number of mice at start 48 93
Animal censor events are denoted by + marks in the plot
TJL – male
TJL – male      
4-OH-PBN effect on survival, males, test site = TJL
Log-rank test chisq = 0.805 p = 0.3696
Wang-Allison test odds ratio = 0.8145 p = 0.7955
Quantiles 4-OH-PBN Control % difference
25% died before day: 491 553 -11 %
Median lifespan (days) 704 757 -7 %
75% died before day: 896 875 +2 %
90% died before day: 961 967 -1 %
Max lifespan observed (days) 1077 1216
Number of mice at start 58 125
Animal censor events are denoted by + marks in the plot
UM – female
UM – female      
4-OH-PBN effect on survival, females, test site = UM
Log-rank test chisq = 0.5149 p = 0.473
Wang-Allison test odds ratio = 0.6972 p = 0.7505
Quantiles 4-OH-PBN Control % difference
25% died before day: 741 772 -4 %
Median lifespan (days) 827 916 -10 %
75% died before day: 984 1005 -2 %
90% died before day: 1092 1111 -2 %
Max lifespan observed (days) 1135 1210
Number of mice at start 38 82
Animal censor events are denoted by + marks in the plot
UM – male
UM – male      
4-OH-PBN effect on survival, males, test site = UM
Log-rank test chisq = 0.0432 p = 0.8353
Wang-Allison test odds ratio = 1.016 p = 1.0
Quantiles 4-OH-PBN Control % difference
25% died before day: 756 727 +4 %
Median lifespan (days) 879 864 +2 %
75% died before day: 1002 995 +1 %
90% died before day: 1128 1121 +1 %
Max lifespan observed (days) 1243 1305
Number of mice at start 57 106
Animal censor events are denoted by + marks in the plot
UT – female
UT – female      
4-OH-PBN effect on survival, females, test site = UT
Log-rank test chisq = 0.0111 p = 0.916
Wang-Allison test odds ratio = 1.4111 p = 0.5678
Quantiles 4-OH-PBN Control % difference
25% died before day: 757 744 +2 %
Median lifespan (days) 844 880 -4 %
75% died before day: 951 994 -4 %
90% died before day: 1111 1076 +3 %
Max lifespan observed (days) 1206 1188
Number of mice at start 47 96
Animal censor events are denoted by + marks in the plot
UT – male
UT – male      
4-OH-PBN effect on survival, males, test site = UT
Log-rank test chisq = 4.2839 p = 0.0385
Wang-Allison test odds ratio = 1.3365 p = 0.5838
Quantiles 4-OH-PBN Control % difference
25% died before day: 621 592 +5 %
Median lifespan (days) 808 739 +9 %
75% died before day: 969 877 +10 %
90% died before day: 1039 988 +5 %
Max lifespan observed (days) 1332 1132
Number of mice at start 50 119
Animal censor events are denoted by + marks in the plot


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Statistical definitions