Introduction

Study phases can be used to model changes in the patient treatment or visit actions over time. E.g., study phases can be used to model switching all patients to a new formulation at a given point in time.  It’s important to clarify the use of a Phase in 4C versus traditional study phases. Most often, a phase in a study is used to identify parts of the study where a change in the study design may occur, such as a re-randomization, dispensing changes, or other events. Many studies may have a Double-Blind Phase followed by an Open Label Phase. In most cases, all patients will follow the same visit schedule and move to the Open Label Phase at a specific visit. For Example, all patients move to Open Label when they reach Visit 20 of the study. They receive double blind kits at every visit before Visit 20 and receive open label kits starting at Visit 20 and through the end of the study. This example does not need to use Phases in the 4C model since all patients move to the OL Phase at the same Visit.

An example of when phases would be used in 4C is if the patients move to an open label phase (meaning, the dispensing will change from a double-blind kit type to an open label kit type) at a defined date. This means that, regardless of what visit a patient is at, they will be dispensed something different at the date defined in the Phases Table. Another example would be when a formulation changes and all patients need to get the new kits dispensed to them as soon as they are available, regardless of what visit the patient is at.

Phases can be used to define, at a specific date, changes in:

• Dispensing

• Randomization

• Dose Level

• Conditionals

• Move to Events (Visit Skips)

• Discontinuation

• Screen Fail

To use study phases:

• define study phases using the Study Phases table and

• define the visit actions that occur in each defined phase by using the Study Phase column in the visit actions table.

Phase Code

Details the names of the phases to be used in the Visit Actions Table.

Phase code is a mandatory entry and must be unique for each phase. If no phase code is entered for a phase or is entered more than once, an interpretation error message is shown.

Start Date

Defines the start date of a study phase.

Start date is a mandatory entry for each phase. If no start date is entered for a phase, an error message is shown.

The Start Date must be:

• a valid absolute date (e.g. 01-Sep-2023) or

• an offset from FPI (e.g. FPI + 12 months) or

• an offset from previous study phase start (e.g. Phase 1 + 12 months).

Offsets must be specified as [anchor] + [integer] [unit]

• Accepted anchors are

  • FPI and

  • study phase

• Accepted units are

  • days (default)

  • months

  • years

Description

Describes the study phase. This is informational only and is not evaluated during interpretation.

Example Study Phases Table

Study Phases