Directional baseline differences and type i error probabilities in randomized clinical trials
| Autor: | John E. Overall, Kevin N. Magee |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Pharmacology
Statistics and Probability Analysis of covariance Analysis of Variance Models Statistical Randomized experiment Outcome (probability) law.invention Correlation Randomized controlled trial law Statistics Econometrics Pharmacology (medical) Analysis of variance Baseline (configuration management) Monte Carlo Method Probability Randomized Controlled Trials as Topic Mathematics Type I and type II errors |
| Zdroj: | Journal of Biopharmaceutical Statistics. 2:189-203 |
| ISSN: | 1520-5711 1054-3406 |
| DOI: | 10.1080/10543409208835039 |
| Popis: | Adequate correction for baseline differences that occur in the same or opposite direction from inferred treatment effects in a simple randomized experimental design is addressed by Monte Carlo simulation. Results confirm that the analysis of covariance (ANOVA) can provide appropriate correction whether baseline means differ significantly by chance in the same or opposite direction from the inferred treatment effect. The results from analysis of simple pre-post difference scores are highly dependent on the direction of chance baseline deviations in relation to the directional treatment effect that would be inferred from rejection of the null hypothesis. The attempt to correct for baseline differences by expressing outcome as percentage of baseline entails directional bias that depends on the location of the zero point, the direction of change, and the level of correlation between baseline and follow-up measurements. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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