As our population ages and medical advances increase life expectancy, drug developers are facing an emerging gap in clinical research: lack of evidence to guide treatment decisions for people over 65.

Almost a year ago, the FDA held a public meeting asking for suggestions on how to include more older people in clinical trials. Since then, a number of experts around the world have expressed similar concern that there is little evidence to tell them what drug or treatment works in elderly patients. In a global survey of physicians I conducted in January, respondents said the most under-represented patient population in clinical trials is the elderly.

The prevailing assumption is that the clinical data from a drug tested in a 50-year-old white male is a valid basis for treatment decisions for a 90-year-old female. 

It is common for a trial of a new cancer drug to be tested on patients in their 40s and 50s who do not have other ailments and who are receiving only the trial treatment. While the clinical results are valid for the patients tested, how confident are we that those results will be the same for a patient in her 80s who may be managing a number of other chronic conditions besides cancer?

One of the main reasons to study the elderly is that older patients tend to have several chronic diseases. It’s estimated that somewhere between 15% and 20% of people over the age of 65 are polypharmacy patients. These patients likely are taking more than 10 different drugs at the same time. That puts them at an increased risk of treatment mistakes and side effects.

Drug interactions are just one concern. As the body ages, it becomes less efficient in processing drugs, meaning it takes longer to clear chemicals out of the system. Because of this, it is possible elderly patients are being overdosed. 

An evaluation published by the British Medical Journal revealed elderly patients were part of the exclusion criteria for nearly a third of trial protocols. At the same time, elderly patients make up more than a third of the population that ultimately would benefit from the use of those drugs in practice.

For example, less than 10% of trial participants in antidepressant trials are over 65, even though incidence of depression grows as the population ages.  The average age of patients in trials for high blood pressure is 62, but the average age at which patients are first diagnosed with high blood pressure is 70. 

When a drug is shown to reduce the risk of stroke in younger people, should we trust that older people should use it?  Evidence suggests hypertension isn’t a risk factor for stroke for people in their 80s. When prescribing a drug to an elderly patient that lowers blood pressure, there is an increased risk that side effects, such as dizziness, could lead to falls. We need better evidence to weigh the likelihood of a stroke versus a broken hip.

If we don’t know for certain whether a drug trial in a younger population will help older people, why aren’t more elderly people included in trials? 

It’s partly prejudice and partly economics. Physicians might not recruit older patients as aggressively because they view them as less willing and able to participate. Sponsors might choose to exclude the elderly from their protocols because it is more challenging to determine the exact outcome of the trial drug when patients already are taking medicines for co-morbid conditions.

But according to FDA Commissioner Margaret A. Hamburg, M.D., when a more diverse population participates in clinical trials, we increase the potential to know more about the extent to which different subgroups might respond to a medical product. The result is greater assurance in the safety and effectiveness of products used by diverse populations.

Clinical research needs to fill the gap in our knowledge about the risks and benefits of medications for use in elderly patients, and the only way to achieve that is by including older patients in clinical trials. 

Having this information could help physicians make better decisions, reduce treatment duration, reduce doses and improve the overall quality of life for the elderly. 

Matthew Howes is senior vice president, marketing innovation for PALIO, an inVentiv Health company. A leader in digital strategy, he has provided the fuel for digital businesses visited by over 100 million people every month.

This article was reprinted from CWWeekly, a leading clinical research industry newsletter providing expanded analysis on breaking news, study leads, trial results and more. Subscribe »