Sample Size Determination. Group sample sizes were chosen empirically for this initial Phase 2 study to determine the safety and tolerability of RIST4721.
Sample Size Determination. For the primary efficacy endpoint on change from baseline (worst pain experienced within 1 month of screening visit) to 6-month on VAS, two sample t-test was used to calculate the sample size using PASS 15 power analysis and sample size software (NCSS LLC, UT USA). The mean change was assumed to be the same, and standard deviation was assumed to be the same at 2.4 for both the LiquiBand FIX8® and AbsorbaTack™ for XXXX and TEP laparoscopic groin hernia (femoral and inguinal) repair. The non-inferiority margin was set to 0.9 (as supported by the following references; [21] [22]), alpha at 0.025, and the target statistical power at 80%. Under these assumptions, a total sample size of 226 subjects (113 per group) is required for the study. With an attrition rate of about 20%, a total of 284 subjects will be enrolled.
Sample Size Determination. The study sample size is not based on null hypothesis significance testing. A sample size of 13 participants has been selected based on convention for this type of study (Strickland, 1971). To accommodate a 25% dropout rate, approximately 17 participants will be enrolled to achieve 13 evaluable participants.
Sample Size Determination. With a total of 60 subjects (30 per group) and assuming a drop-out rate of no more than 20%,
Sample Size Determination. To demonstrate the efficacy of a combination therapy, the combination (phentermine and topiramate) must be superior to both of the individual components that comprise the combination and placebo, at ***. The projected sample size of this trial is determined by the anticipated mean difference between the *** and the ***. In a previously conducted VIVUS *** trial, *** had a ***, compared to ***. In this trial, the effect of the *** is roughly equal to ***. Assuming the weight reduction for ***, and the weight reduction for ***, then the estimated effect of *** would be ***. Similarly, the estimated effect for *** would be ***. The effect of the *** is estimated as ***. Therefore, the estimated sample size is based on detecting a mean difference of *** between the ***. The pooled standard deviation for percent change in body weight from this *** trial was approximately ***. With 100 subjects in each of the *** in this trial, the trial should have more than *** power to demonstrate that the *** is an effective combination.
Sample Size Determination. In a previous *** study evaluating the effects of VI-0521, subjects treated with a *** had a mean (SD) weight loss of *** for subjects receiving *** treated subjects. If similar standard deviations are achieved in the present trial, the planned sample size of at least 250 subjects per treatment group should provide *** power to detect these differences.
Sample Size Determination. In total, approximately 200 subjects will be randomized in a 1:1 ratio to receive 1 of the following study drugs: • Vibegron 75 mg (N = 100) • Placebo (N = 100) At most, 50% of randomized subjects (approximately 100 subjects total [50 per treatment arm]) will have IBS-M; and at least 50% of randomized subjects (approximately 100 subjects total [50 per treatment arm]) will have IBS-D, and the IBS-D subgroup will be used for the primary endpoint analysis. Assuming a total of 10% of subjects will discontinue prior to Week 12 (for any reason), there will be a minimum of approximately 90 evaluable IBS-D subjects (45 in the vibegron arm and 45 in the placebo arm) at the end of Week 12. The study has approximately 60% power to detect a between-group treatment difference of 20% in proportion of abdominal pain responders at a 2 -sided test at the α = 0.10 level assuming a responder rate of 51% versus 31% for vibegron and placebo, respectively. The assumptions were based on results from a solabegron study female subgroup analysis [Xxxxxxxx, 2008].
Sample Size Determination. The primary objective of this study is to compare the effects of treatment for 3 years with A previous large long-term (3-year) study in COPD (FLIT78, ISOLDE) reported all-cause mortality rates of 16% with active treatment (FLIXOTIDE*) and 21% with * FLIXOTIDE is a Trade Mark of GlaxoSmithKline group of companies. placebo among all subjects randomised [Waterhouse, 1999], and 18% vs. 27% among subjects with FEV1 <60% predicted. Among subjects in this sub-group, the surviving proportions at annual intervals were as follows.
Sample Size Determination. In previous studies in adults, VI-0521 mid-dose (PHEN/TPM 7.5 mg/46 mg) resulted in a placebo-subtracted BMI reduction of 2.4 units with a standard error approximately 0.16 units and a within treatment standard deviation of 2.9. A very conservative estimate of the treatment difference between the mid-dose and placebo would be 2 units of BMI which represents more than 2 standard errors below what was observed before. If we enroll 200 subjects (50 placebo, 50 mid-dose, and 100 top-dose), we will have at least 90% power to detect a statistically significant difference between the top-dose (PHEN/TPM 15 mg/92 mg) and the placebo because we could assume that the top-dose will have a higher effect size than the mid-dose. This calculation assumes that there will be an approximately 30% dropout rate. This sample size will also provide approximately 80% power to detect a statistically significant difference between the mid-dose and placebo.
Sample Size Determination. The sample size is based on the ability to detect a statistically significant treatment difference in the weekly number of UI episodes at Week 6 following treatment in the two Dysport® arms compared to the placebo arm. Assuming a decrease of 21 UI episodes per week in each Dysport® arm and a decrease of 12 UI episodes per week in the placebo arm, with a common standard deviation of 20 UI episodes, 80% power, and an alpha of 0.025 (as testing of both the 600 U and 800 U doses vs. the placebo dose will be performed simultaneously), a sample size of N=96 subjects per dose group for the primary analysis (a total of 288 subjects) is needed. Assuming a treatment group random allocation ratio 1:1:1, a sample size of 106 subjects in each treatment group will have 80% power to detect a difference in UI of 9 episodes (the difference between UI in Dysport® 600 U and Dysport® 800 U groups and in placebo group assuming a common standard deviation equal to 20 episodes and a dropout rate equal to 10% with a 0.025 two-sided type one error rate. A total of 318 subjects would therefore need to be enrolled. However, in order to ensure that the development program will deliver adequate Dysport exposure data to meet ICH E1 guideline recommendations, a total of 330 subjects are planned to be randomised.
