Antidementia drugs use in patients with Alzheimer's disease

Date of Approval
Application Number
Technical Summary

Study objective: To describe antidementia drugs use in newly diagnosed AD patients in the CPRD database.
study design: this is a descriptive study without hypothesis testing. Patients who were newly diagnosed with AD in 2018-2019 will be followed up on their antidementia treatments for at least one year. The antidementia treatment during the follow-up time period after AD diagnosis will be described, including the drug names (donepezil, rivastigmine, galantamine, memantine), percentages of exposure, route, dose (initial dose, titrated dose), duration (time to start and time to switch/discontinuation). If a patient receives more than one anti-dementia drug within a 21-day window from the start of a line of therapy, the patient is determined to be using combination therapy in that line of therapy. Once a patient has started a new drug (outside of the initial 21-day window), we determine that the patient has moved to the subsequent line of therapy. In later lines of therapy, a patient is also determined to be using combination therapy if the patient receives a new drug while the preceding drug is still ongoing (the patient added the new drug to their current therapy). We will require the patients to have a second fill of both components to be qualified as combination therapy. If, however, the previous agent is not continued once a new agent is started, the patient is determined to have switched therapies. The drug discontinuation is defined as the no refill of the drug in 8 weeks after the days of supply.
Statistical methods: Antidementia drugs used in newly diagnosed AD patients will be described by their names, route, and dose. The duration of treatment will be described by Kaplan-Meier methods, and the outcome will be switching to the second line, discontinuation of the first line without switching, disenrollment, or end of study.

Health Outcomes to be Measured

For each line of therapy, we will describe the drug names, route (pill or patch), dose, time to start, time to switch, and time to discontinuation.

The outcomes are the percentages of each therapy among the first three lines of therapies. We will report time to start, time to discontinue, time to switch for each line of therapy.

We will also report the percentage of patients on antidementia therapy (and percentages on first/second/third line of therapy) at 6-month, 12-month, 18-month, 24-month follow-up.


Wenjun zhong - Chief Investigator - Merck & Co., Inc.
Wenjun zhong - Corresponding Applicant - Merck & Co., Inc.
Xinyue Liu - Collaborator - Merck & Co., Inc.