Sample size
PDO
The alternative hypothesis states that a successful drug prediction using drug screens in PDO is possible in more than 65% of cases. Sample size was determined using a one sample test. The null hypothesis that a drug prediction will only be possible in 65% of patients will be tested against a one-sided alternative (that the proportion is larger than 65%). Assuming that the real proportion is 85%, a sample of 31 participants should show a statistically significant result at 5% significance and 80% power using an exact binomial test. Assuming an early termination of 10% of patients, a total number of 34 patients will have to be included. Thus, the study will recruit 31 patients that have completed the full 6 instillation cycles.