Recruiting older people to clinical trials

Posted on Aug 7, 2014 by Leslie Gelling in Research

Older people are under-represented in clinical trials. There are currently 10 million people over the age of 65 (an arbitrary and flawed indicator of old age) living in the UK and this figure is growing all the time. It is estimated that there will be 5.5 million more people over the age of 65 in 20 years and approximately 19 million in the UK by 2050.

The elderly are also the most significant users of healthcare resources, including medicines and devices. For example, the majority of cancer diagnoses are made in those older than 65 but as the older population continues to grow so will the number of older people being treated for cancer and other conditions of old age.

It is, therefore, surprising that older people are consistently under-represented in clinical trials. Many of the drugs used to treat older people were developed and tested in younger people. This under-representation of older people in clinical trials has been acknowledged for many years so why does this problem still exist?

One of the main reasons for this is that clinical trials are often unavailable to older people or researchers don’t actively seek to recruit older people to their clinical trials. Perhaps sponsors and researchers believe that older people might not want to participate in clinical trials or might be less reliable trial participants. Whatever the reason, there is evidence to suggest that clinical trials aren’t made available to older people.

Another reason for this under-representation of older people in clinical trials is that older people are often ineligible for inclusion in these trials. They might not meet unjustifiable age-related inclusion criteria or they have a co-morbidity or are using contraindicated medications. Rather than strengthening a clinical trial, excluding older people on these grounds could actually lessen the real world generalisability of the results and how they might be used to guide the treatment of older people.

This situation can create difficulties for prescribing clinicians and for patients. Older patients being treated are not representative of the participants in most clinical trials. Research ethics committees in the UK have increasingly looked unfavorably on unjustifiable age and other restrictions in inclusion and exclusion criteria but there appears to remain a default expectation that clinical trials will include only younger healthier people.

Sponsors and researchers need to be more open to recruiting older people into clinical trials and to appreciate the value this can bring to these trials. Unjustified age limits need to be avoided but this will only happen if all those involved in planning and conducting clinical trials, including clinical research nurses, are proactive in seeking to eliminate such restrictions. There remains a gap between clinical trials and the real world of clinical decision-making and patient treatment.