Start practicing

Biostatistics & Research · single question

In statistics, what does the p-value represent?

  1. The probability that the study results are clinically significant
  2. The probability that the observed results occurred by CHANCE alone (if the null hypothesis is true)
  3. The confidence that the treatment is effective
  4. The ratio of true positives to total positives
Show answer and explanation

Correct answer: B. The probability that the observed results occurred by CHANCE alone (if the null hypothesis is true)

The p-value is the probability of obtaining results at least as extreme as those observed, assuming the null hypothesis is true. A p-value <0.05 means there is less than 5% probability that the observed difference occurred by chance — thus we reject the null hypothesis. The p-value does NOT measure clinical significance, effect size, or the magnitude of the difference. A statistically significant result (p<0.05) may not be clinically meaningful.

Practice Biostatistics & Research questions Biostatistics & Research study notes

More Biostatistics & Research practice questions