Clinical Trials: Sample Size Calculation and Dropout Accounting

Play an AI-generated podcast conversation about this lesson

What is a common issue that can lead to an underpowered trial in a clinical trial?

Participants missing outcome data (correct)

Incorrect measurement of the primary outcome variable

Incorrect randomization of participants

Incorrect calculation of the standard deviation

What is the intention-to-treat principle in clinical trials?

Analyzing only participants who showed improvement

Analyzing participants based on the treatment they actually received

Analyzing only participants who completed the trial

Analyzing participants based on the treatment they were randomized to (correct)

Why should sample size be specified in the grant application and protocol?

To ensure that the trial is funded

To ensure that the trial is adequately powered (correct)

To ensure that the trial is completed quickly

To ensure that the trial is ethical

What is the recommended pilot trial sample size per treatment arm for a medium standardised effect size?

15 Signup and view all the answers

What is the purpose of inflating the sample size in a clinical trial?

To account for participant dropout Signup and view all the answers

What is the primary purpose of a pilot trial in clinical trial design?

To demonstrate the feasibility of a larger trial Signup and view all the answers

What is the relationship between the sample size needed at recruitment and the retention rate at the primary follow-up timepoint?

Sample size needed at recruitment = 1 / Retention rate at primary follow-up timepoint Signup and view all the answers

Why is formal hypothesis testing for effectiveness not recommended in a pilot trial?

Because the pilot trial is usually underpowered to do this Signup and view all the answers

Why is sample size calculation considered an educated guess?

Because it depends on various factors, including the type of outcome variable and the expected effect size Signup and view all the answers

What is the recommended sample size for estimating a participation rate of 50% to within a 95% confidence interval of +/-10%?

100 Signup and view all the answers

What is the purpose of estimating a sample size for a pilot trial?

To determine the feasibility of a larger trial Signup and view all the answers

Why should the size of a pilot trial be large enough?

To convince a funder to support a larger trial Signup and view all the answers

What is the primary objective of performing sample size calculations in a clinical trial?

To avoid making an error in the study Signup and view all the answers

What is the purpose of power calculations in a clinical trial?

To estimate the number of participants required to achieve a statistically significant result Signup and view all the answers

What is the main reason for conducting sample size calculations in a clinical trial?

To ensure the trial is ethical and justifiable Signup and view all the answers

What is the role of the sample size calculation in a clinical trial?

To estimate the number of participants required to achieve a statistically significant result Signup and view all the answers

What is the consequence of underestimating the sample size in a clinical trial?

The study may be underpowered, leading to an increased risk of type II error Signup and view all the answers

What is the relationship between the sample size and the power of a clinical trial?

As the sample size increases, the power of the study increases Signup and view all the answers

Clinical Trials: Sample Size Calculation and Dropout Accounting

Choose a study mode

Podcast

Questions and Answers