cusum_limit_exact {cusum} | R Documentation |
This function only works for very small sample sizes (<= 15), as it permutes through all possible outcome sequences and estimates the percentage of runs that reach a specific CUSUM values.
cusum_limit_exact(n_patients, failure_probability, odds_multiplier, alpha)
n_patients |
Integer. Number of patients in monitoring period /sample size |
failure_probability |
Double. Baseline failure probability |
odds_multiplier |
Double. Odds multiplier of adverse event under the alternative hypothesis (<1 looks for decreases) |
alpha |
Double. False signal probability of CUSUM |
Returns the control limit for signalling performance change for small sample sizes (double)
# calculate exact control limits for alpha = 0.05 cusum_limit_exact( failure_probability = 0.1, n_patients = 10, odds_multiplier = 2, alpha = 0.05 )