When to use the Efficacy Evaluable versus Intent-To-Treat Population in your Clinical Analysis

The efficacy evaluable population (EEP) and the Intent-to-treat (ITT) population are patient populations that are enrolled into a clinical study and considered for a clinical trial statistical analysis, iIn this article, I give a brief explanation of the two populations, their differences, and their relative advantages.

EEP Population:

The EEP is defined as the population of subjects who have all of the required data for the primary efficacy endpoint. This includes subjects who have met all of the eligibility criteria, have received the study treatment as prescribed, and have adequate follow-up for the primary efficacy endpoint.

ITT Population:

The ITT population is defined as the population of all subjects who were randomized to the study treatment, regardless of whether they received the study treatment as prescribed or whether they had adequate follow-up for the primary efficacy endpoint.

The EEP is typically used for the primary efficacy analysis because it is the population that is most likely to have the data necessary to make a reliable assessment of the efficacy of the study treatment. The ITT population is also used for some analyses, such as safety analyses, because it provides a more complete picture of the safety profile of the study treatment.

What are the advantages of one versus the other?

The decision of whether to use the EEP or the ITT population for a particular analysis is made on a case-by-case basis, taking into account the specific objectives of the analysis and the available data.

Here are some of the advantages of using the EEP for statistical efficacy analysis:

• The EEP is more likely to have the data necessary to make a reliable assessment of the efficacy of the study treatment.
• The EEP is less likely to be affected by biases that can occur in the ITT population, such as dropouts and protocol deviations.

Here are some of the advantages of using the ITT population for statistical efficacy analysis:

• The ITT population provides a more complete picture of the safety profile of the study treatment.
• The ITT population is less likely to be affected by imbalances in the baseline characteristics of the treatment groups.

Ultimately, the decision of whether to use the EEP or the ITT population for statistical efficacy analysis is made on a case-by-case basis, taking into account the specific objectives of the analysis and the available data.