The challenges of enrolling older adults into intervention studies.

Adults aged 65 years or older have been routinely and systematically excluded from research. With the number of older adults at a record high and growing faster than any other age group, there must be an increased priority on meeting the enrollment challenges so intervention studies are relevant to this population. The challenge centers around the complexity and heterogeneity of older adults, leaving a gap between older adults who participate in studies and those who exist in the real world. Barriers to enrollment stem from both the researcher and participant side. Eight barriers from the research perspective and six from the participant perspective are identified and discussed. Solutions to these barriers can be approached from a three-tier framework. The lowest tier is direct solutions to problems, the middle involves support from funders and journals, and the top tier considers a comprehensive view of sampling and design decisions.