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Table 2 Facilitators and barriers to participation in Alzheimer's disease clinical trials

From: Addressing the challenges to successful recruitment and retention in Alzheimer's disease clinical trials

Factor

Impact

Participant affected

Description

Low trial awareness

-

B

Those not aware of trials cannot participate.

Comorbidities

-

P

Patients with cardiovascular disease, cerebrovascular lesions, or other medical problems are likely to be excluded.

Medications

-

P

Patients taking a high number of prescription medications are likely to be excluded from participation. Specific trials may have other criteria (for example, excluding medications approved for AD) that prevent some patients from participating.

Risks of side effects

-

B

Risks associated with investigational therapies are barriers to patients and their study partners, who often identify risks to the patient as 'personal' risk.

Barriers associated with procedures

-

P

Patients may be unwilling to undergo procedures such as lumbar puncture, unable to undergo MRIs, or suffer associated frustration with cognitive testing.

Risk of placebo

-

B

Some dyads enroll primarily out of hope for access to new treatments. For these persons, the possibility of receiving placebo is a barrier to participation.

Travel and other logistics

-

B

The requirement of attending study visits at the medical center can deter participation.

Language barriers

-

B

Only patients and study partners who both are capable of fluent communication in the language acceptable for participation are generally eligible to enroll.

Informed consent

-

P

Patients who are not aware of their impairment may lack the capacity to give informed consent.

Informed consent

+

B

Most trials allow a legally authorized representative to provide informed consent on behalf of the patient.

Access to new treatments

+

B

Many participants enroll in trials in the hope of direct medical benefit for the patient.

Altruism

+

B

The desire to assist medical research is a commonly cited reason for participating in AD trials.

  1. Impact: Facilitator (+), barrier (-). Participant impacted: patient (P) or both (B) patient and caregiver. AD, Alzheimer's disease; MRI, magnetic resonance imaging.