Skip to main content

Advertisement

Table 2 Sequential testing on population standard deviation σ

From: Group-sequential analysis may allow for early trial termination: illustration by an intra-observer repeatability study

Number of interim analyses Observed standard deviation, P value (sample size), respective significance level, and upper confidence limit at analysis time point
Interim analysis 1 Interim analysis 2 Interim analysis 3 Final analysis
0 SD = 1.060
P = 0.0022 (N = 45)
α 1  = 0.05
95% uCL 1.288
1 SD = 1.415
P = 0.3900 (N = 23)
α0.5 = 0.025
97.5% uCL 2.002
SD = 1.060
P = 0.0022 (N = 45)
α 1  = 0.05
95% uCL 1.288
2 SD = 0.909
P = 0.0162 (N = 15)
α 0.33  = 0.0167
98.33% uCL 1.495
SD = 1.255
P = 0.1162 (N = 30)
α0.67 = 0.0333
96.67% uCL 1.653
SD = 1.060
P = 0.0022 (N = 45)
α 1  = 0.05
95% uCL 1.288
3 SD = 1.044
P = 0.0984 (N = 11)
α0.25 = 0.0125
98.75% uCL 2.006
SD = 1.415
P = 0.3900 (N = 23)
α0.5 = 0.025
97.5% uCL 2.002
SD = 1.185
P = 0.0452 (N = 34)
α0.75 = 0.0375
96.25% uCL 1.519
SD = 1.060
P = 0.0022 (N = 45)
α 1  = 0.05
95% uCL 1.288
  1. SD standard deviation, uCL upper confidence limit, italics rejection of null hypothesis