Question

A new medication for heart failure is being developed and has had a statistically significant effect on contractility in clinical trials. Which of the following would NOT likely cause the drug to be held back from common use? (A) The value of \(a\) used was 0.5. (B) Similar compounds display toxicity. (C) The effect size is clinically insignificant. (D) The study had low power to detect a difference.

Short answer

Option (A) would NOT likely cause the drug to be held back.

Step-by-step solution

- Understand the question

The question asks which option would NOT likely cause the drug to be held back from common use. This involves understanding why each option might or might not cause a delay.

- Evaluate Option (A)

The value of 𝑎 used was 0.5. This option seems unclear without further context. However, a 𝑎 value of 0.5 typically represents the level of statistical significance. Since the problem states the effect was statistically significant, this option is less likely to cause a delay.

- Evaluate Option (B)

Similar compounds display toxicity. Toxicity in similar compounds is a clear red flag that would likely cause the drug to be delayed or held back.

- Evaluate Option (C)

The effect size is clinically insignificant. If the effect size is clinically insignificant, it means the medication might not provide enough benefit, thereby causing delays or prohibiting its common use.

- Evaluate Option (D)

The study had low power to detect a difference. A study with low power can lead to unreliable results, which can definitely cause delays in drug approval.

- Conclusion

After evaluating all options, Option (A) stands out as the least likely to cause the drug to be held back from common use, given that a value of 0.5 alone does not inherently indicate an issue, especially if the results were statistically significant.

Key concepts

clinical trials

Clinical trials are a crucial step in drug development. They involve testing new medications on human participants to ensure safety and effectiveness before the drug is marketed.
Clinical trials are typically conducted in multiple phases, each with a specific purpose:

• Phase I: Tests safety and dosage on a small group of healthy volunteers.
• Phase II: Evaluates effectiveness and further examines safety on a larger group of patients.
• Phase III: Confirms effectiveness, monitors side effects, and compares the drug to commonly used treatments on diverse patient populations.

Ensuring statistical significance and clinical relevance of trial outcomes is vital to determine whether a new medication should proceed to the next phase or be approved for public use.

statistical power

Statistical power is the probability that a study will detect an effect when there is an effect to be detected. A study with high statistical power is more likely to produce reliable results.
Several factors can influence statistical power:

• Sample size: Larger sample sizes generally increase power.
• Effect size: Larger effects are easier to detect, leading to higher power.
• Significance level: A higher alpha level (e.g., 0.05) increases power but also raises the risk of Type I error (false positive).

In the original exercise, a study with low power could lead to unreliable results, which may cause delays in drug approval.

effect size

Effect size is a measure of the magnitude of the difference between groups in a study. It helps to understand the clinical significance of the results.
Common ways to measure effect size include:

• Cohen's d: Measures the difference between two means in terms of standard deviation.
• Odds ratio: Used in logistic regression to measure the association between an exposure and an outcome.
• Correlation coefficient: Measures the strength of the relationship between two variables.

An effect size that is clinically insignificant, as mentioned in the exercise, might indicate that the medication does not provide enough benefit to warrant widespread use.

drug development

Drug development involves a series of steps to bring a new medication from discovery to market. The process can be complex and includes:

• Discovery and preclinical research: Identifying potential drug candidates and testing them in the lab and on animals.
• Clinical trials: Conducting human trials to assess safety and efficacy.
• Regulatory approval: Submitting trial data to regulatory authorities (e.g., FDA) for approval.
• Post-marketing surveillance: Monitoring the drug's safety and effectiveness in the general population.

Throughout this process, maintaining robust scientific and ethical standards ensures that only safe and effective drugs are approved for public use.