Lesson 10: Missing Data and Intent-to-Treat

Overview Section

Data imperfections can be classified as protocol non-adherence, missing or incomplete observations, or methodologic errors. Two different perspectives have been applied to address the situation with imperfect data.

  • The explanatory approach corresponds to acquiring information and determining biological effects, which typically is done for efficacy studies.
  • The pragmatic approach corresponds to interpreting results according to general use, which typically is done for effectiveness studies.

Distinguishing between the two approaches is useful in determining how to deal with data imperfections.


Upon completion of this lesson, you should be able to:

  • Apply the terms evaluable and inevaluable to patients in a clinical trial appropriately.
  • Differentiate between a pragmatic approach and an explanatory approach and the conditions for which each is appropriate.
  • State the conditions under which data imputation is reasonable.
  • State the advantage of multiple imputation over simple data imputation.
  • Recognize the conditions under which the International Conference on Harmonization would allow a patient’s data to be excluded from statistical analysis.