Power Analysis for Survival Analysis, Exponential with Accrual & Dropouts (Power Calculation)

Power calculation for Survival Analysis, Two-group test of equal exponential with accrual and dropouts, with options for charts of Power vs. Sample Size, vs. Lambda 2, and vs. Alpha Level

General

Element Name Description
Lambda 1 Exponential parameter for group 1.
Lambda 2 Exponential parameter for group 2.
Sample Size (N) Sample size for the power calculation (acceptable range 2 to 150000).
Accrual Period (T0) Accrual period for the power calculation (acceptable range 1 to 10000).
Follow-up Period (T) Follow-up period for the power calculation (acceptable range 1 to 10000).
Dropout Rate (D) Dropout Rate for the power calculation.
Alpha Level Alpha level (Type I error rate for the overall significance test) (Acceptable range 0.0001 to 0.25)
Hypothesis type Null hypothesis to be tested:

 Lambda 2 = Lambda 1, (Two-tailed, null and alternative hypotheses of form - H0: Lambda2 = Lambda1, H1: Lambda2 <> Lambda1)

 Lambda 2 <= Lambda 1, (One-tailed, null and alternative hypotheses of form - H0: Lambda2 <= Lambda1, H1: Lambda2 > Lambda1)
Detail of computed results reported Output level of detail selection:

 Power Calculation produces Power Calculation Spreadsheet;

 Pwr Calc plus Charts option produces, in addition, Power vs. Sample Size, vs. Lambda 2, and vs. Alpha Level charts.

Chart Parameters

Element Name Description
Number of Steps (For charts only). Number of individual steps for which to calculate power between the starting and ending parameter values for Power Charts (Min 4, Max 100).
Starting Sample Size (For charts only). Initial sample size for calculation of all Power vs. Sample Size charts.

 (Acceptable range 2 to 140,000)
Ending Sample Size (For charts only). Final sample size for calculation of all Power vs. Sample Size charts.

 (Acceptable range 5 to 150,000)
Starting Lambda 2 (For charts only). Initial Lambda 2 value for calculation of Power vs. Lambda 2 chart (acceptable range 1e-010 to 0.9999).
Ending Lambda 2 (For charts only). Final Lambda 2 value for calculation of Power vs. Lambda chart (acceptable range 1e-005 to 0.9999).
Starting Alpha Level (For charts only). Initial alpha level for calculation of Power vs. Alpha Level chart (acceptable range 0.0001 to 0.2499).
Ending Alpha Level (For charts only). Final alpha level for calculation of Power vs. Alpha Level chart (acceptable range 0.0002 to 0.25).