Table 1.

Examples and Limitations of Using Technology for Measurement in Older Adults

Construct	Summary of current measurement techniques and limitations
Physical activity	Cut points for adults may not work in older adults; therefore, new cut points were developed in a laboratory setting.13 However, these accelerometer-based cutoffs may not capture all meaningful behaviors and may misclassify the activity level of functionally impaired older adults with slow walking speed.24 There are new machine-learned walking algorithms that were developed and validated in free-living older women.25 Additional hip and wrist accelerometer algorithms are available.26
Posture/sitting	Thigh-worn activPALs are valid for posture in all age groups, but older adults’ skin may be more sensitive and thigh-worn devices could be challenging in the long term. New machine-learned sitting algorithms have been developed and validated for older women but must be tested in other populations.25
Gait, balance, frailty, or mobility	For inertial devices (accelerometers, gyroscopes, and magnetometers), the most common placement locations are the lower back, shank, thigh, head, and trunk; whereas for force sensors, the location is typically the plantar surface of the foot. In-home monitoring allows for long-term monitoring of gait speed.27 There is not currently a clinically sensitive technology to use in clinical care settings that quantifies relevant gait parameters to indicate frailty status.28 Future research needs to enhance dynamic balance and gait control, which is more generalizable to everyday tasks than static balance.
Falls	Sensors for fall prevention are typically located on the lower back.29 Europe is developing a human-centered design platform called the WIISEL for assessing fall risk in older adults.30 It will allow researchers to quantify activity and assess the quality of gait under real-life conditions and enable clinicians to evaluate and monitor fall risk in elderly patients. The sensors within shoe insoles provide constant recording, but it is unclear who receives the feedback from the continuous monitoring. Danielsen et al.29 proposed a prospective and contextaware fall-risk awareness protocol that uses sensors to capture expected chance of fall risk and alert health professionals, caregivers, and patients. Feedback should be associated with a risk of falling rather than simply identifying prospective fall risk. Apps can support interactions between clinicians and patients. Context assessment needs to consider more than the current situation but also evaluate how performance of activities evolves in the long term to identify trends for fall risk assessment.29
Life space	Passively measured GPS is promising, but there are issues related to battery life and participants’ privacy concerns in having their locations revealed. Studies exploring life space typically occur in patient populations (i.e., Parkinson disease, dementia), and more research is needed in healthy aging populations.31,32 Combining GPS and accelerometer data allows researchers to calculate number of pedestrian or vehicle trips to further explore the relationship between life space mobility and health.23
Eating and hydration	Image capture via wearables and smartphones documents intake; however, prompting participants to wear the wearable can be challenging. Additionally, battery life on the devices can limit the completeness of data collection. Lightweight wearables including cameras take pictures automatically, resulting in images that create a daily log of intake, offer an approach to capturing intake that may overcome many of the challenges older adults face with dietary intake reporting. Pictures capture times and frequency of meal consumption and could be useful memory joggers as well as valuable information for determining if an intervention needs to be provided.33 Novel Assessment of Nutrition and Ageing (NANA)8 uses tablets with touchscreens and webcams. It is designed to look holistically at nutrition and health by taking measures of diet, mood, cognition, and physical function. Future research should assess the effects of long-term use of technology in older adults and its impact on health behaviors.34

GPS, global positioning system; WIISEL, Wireless Sensor Insole for Collecting Gait Data.