Unless pandemics, climate disasters, or other catastrophes intervene, we can expect that one in six people across the globe will be older than 65 years by 2050 (United Nations Department of Economic and Social Affairs, 2019). Population aging will have the greatest effect in regions that combine high proportions of older adults with high levels of old age consumption, such as North America, Australia, and Europe. The service that older adults consume most dramatically compared with other age groups is healthcare. Research in every nursing field will need to confront this reality by intentionally including older adults in studies. However, research with older adults, particularly the oldest old, may present some unique challenges to nurse researchers. These challenges represent conditions that are common among patients in practice but also are commonly overlooked by caregivers because they do not necessarily interfere with care. Research is not usual care, though, and investigators will have an easier time conducting their projects if they plan for the predictable challenges of working with older adults.

Older adults have been loosely classified into three groups: the youngest old, between about 65 and 74 years of age; the middle-old, aged from about 75-84 years; and the oldest-old who are 85 years of age and older. Across all these age groups, a predictable condition that affects function is presbyopia. Presbyopia is the loss of ability to focus on objects in near space, caused by deterioration in elasticity of the lens of the eye. The patient who must hold reading material at arm's length to focus on the words most certainly is affected. Most older adults purchase inexpensive reading glasses to correct near vision. Unfortunately, older adults admitted to hospitals or encountered in other healthcare settings frequently do not have their reading glasses with them. Presbyopia in older adults is typically ignored by nurses in practice but reading consent forms and self-report questionnaires used in research presents obvious problems. Including a small amount of money in the research budget to buy reading glasses is an easy way to solve the problem and is much less frustrating than trying to read a 20-page consent form aloud to someone who is likely to be hard of hearing.

A second predictable challenge for older adults is presbycusis, age-related hearing loss. About a third of the youngest old and half of those older than 75 years are affected (National Institutes of Health, National Institute on Deafness and Other Communication Disorders, 2018). If research procedures, such as verbal instructions or responses to auditory stimuli, depend on good hearing acuity, it is worthwhile for investigators to test subjects' hearing prior to formally enrolling them in a study. The "whispered voice test," described by Pirozzo, Papinczak, and Glasziou (2003), is a simple and accurate procedure for detecting hearing loss in adults. It can be performed by any nurse in almost any setting in less than a minute. The problem of hearing loss is not as easy to solve as buying a pair of reading glasses. Severely hard of hearing subjects may need to be excluded from the sample in studies demanding good hearing acuity, and this exclusion would need to be noted in the plan for recruitment.

A third predictable challenge is age-related changes in sleep patterns that result in excessive daytime sleepiness. This problem could interfere with research procedures that demand alertness, including some psychomotor tasks, completing lengthy questionnaires, or participating in interviews. Excessive daytime sleepiness may also be a confounding variable in many studies, so measuring baseline sleepiness should be considered in those cases. A simple, well-established test for excessive daytime sleepiness is the Epworth Sleepiness Scale (Johns, 1991). It is an eight-item tool that assesses the likelihood of dozing in different situations and is completed by the subject.

The fourth predictable challenge that will almost certainly become an issue in many studies of older adults is dementia. Although cognitive impairment is not considered normal or inevitable with aging, older adults are at higher risk than other age groups. Dementia may define a study population or may need to be measured at baseline to provide statistical control. It may also interfere with procedures that require sound cognitive processing. Dementia that is more than mild may interfere with the informed consent process, as well, and will need to be acknowledged. Several screening tools exist that can be used by nurse researchers to identify possible dementia. The best known include the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The MMSE is an 11-item tool that takes about 5-10 minutes to administer. The MoCA is a 12-item tool that takes about 15 minutes to administer. It is better than the MMSE at distinguishing mild cognitive impairment from more severe impairment but does require formal training for use. Surrogates, such as family members or individuals with power of attorney for subjects, may and should be included in the consent process for the older adult with cognitive impairment before they participate in research.

Although the Office for Human Research Protections, which maintains regulatory oversight for U.S. research involving humans, does not designate older adults as a vulnerable population, nurse researchers should bear in mind that the risks for this group may vary from other groups. Protections or additional steps may be needed to minimize risks. Protection begins with assessment and includes providing specific accommodations to address the risks. Assessment is readily available in simple forms for each of the four challenges described. Accommodations for these challenges when subjects are affected are usually easy to implement in nursing studies. Not assessing and accommodating for these challenges is poor research practice when subjects are older adults. The key to overcoming these challenges is basically remembering them when designing projects.

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