Question

Your boss asks you to plan the sample size for a randomized, double-blind, controlled trial in the clinical development of a cure for irritable bowl disease. Current standard treatment shall be compared with a new treatment in this trial. The S3-guideline of AWM demonstrated a mean change of the summary score of the validated health related quality of life questionnaire at 8 weeks of 16 with standard deviation 23 under standard treatment. You quote the drop-out rate of 11% from literature (previous phase of clinical development). Your research yielded a clinically important effect of 4 that has been found to be the Minimal Clinically Important Difference (MCID). In order to demonstrate superiority of the new treatment over standard of care, you assume that the change in of the summary score of the validated health related quality of life questionnaire follows a normal distribution, and that the standard deviation is the same for both treatments. How many patientes would one need to recruit for the trial to demonstrate the clinically interesting difference between treatments at significance level 5% with 95% power?

186

likes
932 views

Answer to a math question Your boss asks you to plan the sample size for a randomized, double-blind, controlled trial in the clinical development of a cure for irritable bowl disease. Current standard treatment shall be compared with a new treatment in this trial. The S3-guideline of AWM demonstrated a mean change of the summary score of the validated health related quality of life questionnaire at 8 weeks of 16 with standard deviation 23 under standard treatment. You quote the drop-out rate of 11% from literature (previous phase of clinical development). Your research yielded a clinically important effect of 4 that has been found to be the Minimal Clinically Important Difference (MCID). In order to demonstrate superiority of the new treatment over standard of care, you assume that the change in of the summary score of the validated health related quality of life questionnaire follows a normal distribution, and that the standard deviation is the same for both treatments. How many patientes would one need to recruit for the trial to demonstrate the clinically interesting difference between treatments at significance level 5% with 95% power?

Expert avatar
Darrell
4.5
63 Answers
\frac{2\times\left(1.96+1.645\right)^2\times23^2}{4^2}=859.36 Therefore sample size is 860

Frequently asked questions (FAQs)
What is the equation for finding the roots of a quadratic equation?
+
What is the dot product of vectors A = (1, 2, 3) and B = (-4, 5, 6)?
+
What is the surface area of a right rectangular prism with dimensions 10cm x 15cm x 20cm?
+
New questions in Mathematics
Two fire lookouts are 12.5 km apart on a north-south line. The northern fire lookout sights a fire 20° south of East at the same time as the southern fire lookout spots it at 60° East of North. How far is the fire from the Southern lookout? Round your answer to the nearest tenth of a kilometer
Solution of the equation y'' - y' -6y = 0
I want to divide R$ 2200.00 between Antônio, Beto and Cássia, so that Beto receives half from Antônio and Cássia receives a third of Beto. Under these conditions, how much more will Beto receive than Cássia?
A car tire can rotate at a frequency of 3000 revolutions per minute. Given that a typical tire radius is 0.5 m, what is the centripetal acceleration of the tire?
STUDENTS IN A CLASS LEARN ONLY ONE FOREIGN LANGUAGE. two-sevenths of the students learn German, half of the students learn Spanish, and the remaining six students learn Italian. what is the number of students in this class? detail your reasoning carefully.
(m²-121)
What will be the density of a fluid whose volume is 130 cubic meters contains 16 technical units of mass? If required Consider g=10 m/s2
A construction company is working on two projects: house construction and building construction. Each house requires 4 weeks of work and produces a profit of $50,000. Each building requires 8 weeks of work and produces a profit of $100,000. The company has a total of 24 work weeks available. Furthermore, it is known that at least 2 houses and at least 1 building must be built to meet the demand. The company wants to maximize its profits and needs to determine how many houses and buildings it should build to meet demand and maximize profits, given time and demand constraints.
A merchant can sell 20 electric shavers a day at a price of 25 each, but he can sell 30 if he sets a price of 20 for each electric shaver. Determine the demand equation, assuming it is linear. Consider (P= price, X= quantity demanded)
I need to know what 20% or £3292.75
Solve : 15/16 divide 12/8 =x/y
How many square feet of floor area are there in three two-storey apartment houses, each of which is 38 feet wide and 76 feet long?
Is -11/8 greater than or less than -1.37?
The following table shows the frequency of care for some animal species in a center specializing in veterinary dentistry. Species % Dog 52.8 Cat 19.2 Chinchilla 14.4 Marmoset 6.2 Consider that the center only serves 10 animals per week. For a given week, what is the probability that at least two are not dogs? ATTENTION: Provide the answer to exactly FOUR decimal places
3.24 ÷ 82
Use a pattern approach to explain why (-2)(-3)=6
Determine the increase of the function y=4x−5 when the argument changes from x1=2 to x2=3
The two sides of the triangle are 12 cm and 5 cm, and the angle between the sides is 60°. Cover the area of ​​the triangle!
-5x=115
Sodium 38.15 38.78 38.5 38.65 38.79 38.89 38.57 38.59 38.59 38.8 38.63 38.43 38.56 38.46 38.79 38.42 38.74 39.12 38.5 38.42 38.57 38.37 38.71 38.71 38.4 38.56 38.39 38.34 39.04 38.8 A supplier of bottled mineral water claims that his supply of water has an average sodium content of 36.6 mg/L. The boxplot below is of the sodium contents levels taken from a random sample of 30 bottles. With this data investigate the claim using SPSS to apply the appropriate test. Download the data and transfer it into SPSS. Check that your data transfer has been successful by obtaining the Std. Error of the mean for your data which should appear in SPSS output as 0.03900.. If you do not have this exact value, then you may have not transferred your data from the Excel file to SPSS correctly. Do not continue with the test until your value agrees as otherwise you may not have correct answers. Unless otherwise directed you should report all numeric values to the accuracy displayed in the SPSS output that is supplied when your data has been transferred correctly. In the following questions, all statistical tests should be carried out at the 0.05 significance level. Sample mean and median Complete the following concerning the mean and median of the data. mean =  mg/L 95% CI:  to  mg/L Based upon the 95% confidence interval, is it plausible that the average sodium content is 36.9 mg/L?      median:  mg/L The median value is      36.9 mg/L. Skewness Complete the following concerning the skewness of the data. Skewness statistic =        Std. Error =  The absolute value of the skewness statistic     less than 2 x Std. Error Therefore the data can be considered to come from a population that is      . Normality test Complete the following summary concerning the formal testing of the normality of the data. H0: The data come from a population that     normal H1: The data come from a population that     normal Application of the Shapiro-Wilk test indicated that the normality assumption     reasonable for sodium content (S-W(  )=  , p=   ). Main test Using the guidelines you have been taught that consider sample size, skewness and normality, choose and report the appropriate main test from the following ( Appropriate ONE ) You have selected that you wish to report the one-sample t-test. H0: The mean sodium content     equal to 36.9 mg/L H1: The mean sodium content     equal to 36.9 mg/L Application of the one-sample t-test indicated that the mean is      36.9 mg/L (t(  ) =  , p =   ). You have selected that you wish to report the Wilcoxon signed rank test. H0: The median sodium content     equal to 36.9 mg/L H1: The median sodium content     equal to 36.9 mg/L Application of the Wilcoxon signed rank test indicated that the median is      36.9 mg/L (z =  , N =  , p =   ).