Clinical Trials Discriminate Against Older Persons with Diabetes

by: Ken Covinsky (@geri_doc)

Over half of persons with type 2 Diabetes are over the age of 65.  You would think that there would be tons of research studies that tell us how to best care for older persons with diabetes.  But the truth is that our understanding of geriatric diabetes is a vast wasteland.   Most major studies of diabetes have excluded older persons or have excluded older persons with co-existing disease or functional impairment.  Studies rarely tell us how treatment for diabetes impacts problems older persons care about such as functional impairment, cognitive function, falls, and incontinence.

But surely help must be on the way.  There has been a lot of attention recently to the issue of diabetes in older persons.  So, it must be the case that current studies of diabetes are starting to show they care about the real world patients with diabetes who are older and often have lots of other medical problems in addition to diabetes.

Well, think again.  A study in the Journal of the American Geriatrics Society shows that things are not getting better at all.  Current ongoing studies of diabetes are still characterized by pervasive and systematic discrimination against older patients.

The authors analyzed 440 protocols of ongoing studies of type 2 diabetes.  The findings are very discouraging:

• 66% of studies excluded subjects using an arbitrary upper age limit.  Upper age limits are almost never justified.  Even when drugs are tested in mostly younger patients, they get heavily marketed and used by older patients

• 77% of studies excluded subjects with comorbid conditions–diseases in addition to diabetes.  An acceptable justification for exclusions based on comorbidity was provided less than a 25% of the time.  The vast majority of patients with diabetes have comorbidity.  It is crucial we learn how comorbidity impacts the outcomes of treatment.  Exclusions based on comorbidity often makes the real world application of diabetes studies uninterpretable.

The authors note that responsibility for age discrimination rests with multiple players and notes responsibility of these players going forward:

• Regulatory agencies such as the FDA must develop clear regulations that demand drugs will be tested in the patients that actually will use them before they are allowed to be widely used

• Funders such as the NIH should stop turning a blind eye towards ageism in clinical research

• Human subjects committees should avoid approving protocols that needlessly exclude older subjects

• Older patients and those who care about them should insist that research that improves their care is a major societal need