Phase 4 clinical trials

Phase 4 clinical trials occur after a new drug or treatment has been successfully marketed. They are aimed at defining optimal use, identifying additional side-effects or risks, and comparing the treatment to other existing therapies.

Related Radiopaedia articles

Research

• clinical trials
  • phase 0
  • phase 1
  • phase 2
  • phase 3
  • phase 4
• descriptive studies
  • case report
  • case series
• statistics
  • concepts
    • Bayes' theorem
    • sensitivity and specificity
      • sensitivity
      • specificity
      • sensitivity and specificity of multiple tests
    • positive predictive value (PPV)
    • negative predictive value (NPV)
    • prevalence
    • incidence  
    • likelihood ratio (LR)
    • normal distribution
      • standard error of the mean
      • Z-score
    • type I error
      • p-value
    • type II error
      • power
    • confidence interval
    • ROC curve
    • retrospective studies
    • prospective studies
  • analyzes of variance
    • student t-test
    • paired t-test
    • ANOVA
      • one-way ANOVA
      • factorial ANOVA
      • repeated measures ANOVA
      • multivariate ANOVA (MANOVA)
  • regression
    • single linear regression
    • multiple regression analysis
      • multiple linear regression analysis
      • multiple logistic regression analysis
  • non-parametric statistics
    • chi-squared test
    • kappa
  • bias​
  • cognitive bias in image perception
    • automation bias
    • length time bias
    • lead time bias
    • recall bias
    • selection bias