Effect of Long-Term Exposure to Anticholinergic Drugs on Dementia, an Emulated Target Trial

Study type
Protocol
Date of Approval
Study reference ID
19_075
Lay Summary

Some drugs frequently prescribed in the older population for the treatment of diseases like depression, Parkinson disease, hypertension, schizophrenia, overactive bladder, or seasonal allergies may increase the risk of dementia. However, this is still uncertain as only two studies on people using these medications have reported this potential risk. These medications are used for long periods of time in the elders which poses some challenges to the conduct of any study aiming to evaluate this long-term potential risk. These include the loss of patients over the course of the study, changes of treatment and how to estimate the cumulative effect of the use of these medications.
We propose to add to the body of evidence by conducting a similar design as the one used in clinical trials to test new drugs. We will take advantage of the wealth of information in a large health dataset, the Clinical Practice Research Datalink, which we will combine with novel analytical and statistical methods.

Technical Summary

This study aims to evaluate the risk of dementia in patients initiating treatment with anticholinergic (AC) drugs. We will evaluate this in two different drug classes: antidepressants and antihypertensive drugs. We will compare patients initiating treatment with AC drugs compared with untreated patients and, with patients initiating treatment with similar drug classes but without AC properties. We will use a target trial emulation approach to ease interpretability, avoid selection bias and yield absolute estimates of risk of dementia, as opposed to the currently existing case-control studies.

Health Outcomes to be Measured

Dementia

Collaborators

Joan Forns Guzman - Chief Investigator - RTI Health Solutions ( USA )
Joan Forns Guzman - Corresponding Applicant - RTI Health Solutions ( USA )
Anita Tormos - Collaborator - RTI Health Solutions ( USA )
Barbra Dickerman - Collaborator - Harvard University
Jaume Aguado - Collaborator - RTI Health Solutions ( USA )
Lia Gutierrez - Collaborator - RTI Health Solutions ( USA )
Xabier Garcia de Albeniz - Collaborator - RTI Health Solutions ( USA )

Linkages

HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation