Follow-up Time: Enter the number of years between the last patient accrual to the time of the final analysis.
Accrual Time: Enter the number of years of patient accrual.
Sample Size: Enter n, the planned sample size.
Hazard rate: Enterl, the exponential event rate.
Survival probability and time(default): Enter a time, t (in years), and the probability of patients alive at that time, S(t). The program will calculatel as follows. l=-1n(S(t))/t
Percentage of patients cured: A number between 0 and 1.
Calculation of the Expected Number of Events
Probability of event at analysis time is
P(event|Analysis time t)=1 - e(-l*follow)*(1-e(-l*accrual))/l*accrual).
At times before accrual has completed
P(event|t) =(l-1e(-l t) + t - l-1)/accrual.
At other times
P(event|t) = 1 - e(-l (t-accrual))*(1-e(-l*accrual))/(l*accrual).
The survival density f(t) is assumed to be exponential with ratel and cure rate p, i.e.,
There are three options for calculations. The default option is a table of results in new page. The second and third options provide expected events for a given time, or time at which the expected proportion of events have occurred.