Assessing Smart Phones for Generating Life-space Indicators

Deviations from typical paths: a novel approach to working with GPS data in the behavioral sciences

Background

Behavioral science researchers are increasingly collecting detailed location data such as second-by-second GPS tracking on participants due to increased ease and affordability. While intraindividual variability has been discussed in the travel literature for decades, traditional methods designed for studying individual differences in central tendencies limit the extent to which novel questions about variability in lived experiences can be answered. Thus, new methods of quantifying behavior that focus on intraindividual variability are needed to address the context in which the behavior occurs and the location tracking data from which behavior is derived.

Methods

We propose deviations from typical paths as a data processing technique to separate individual-level typical travel behavior from a location tracking data set in order to highlight atypical travel behavior as an outcome measure.

Results

A simulated data example shows how the method works to produce deviation measures from a location dataset. Analysis of these deviations offers additional insights compared to traditional measures of maximum daily distance from home.

Conclusions

This process can be integrated into larger research questions to explore predictors of atypical behavior and potential mechanisms of behavior change.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12942-022-00305-4.

Lifespace metrics of older adults with mild cognitive impairment and dementia recorded via geolocation data

OBJECTIVE

Lifespace, the physical area in which someone conducts life activities, indicates lived community mobility. This study explored the feasibility of technology-based lifespace measurement for older people with dementia and mild cognitive impairment (MCI), including the generation of a range of lifespace metrics, and investigation of relationships with health and mobility status.

METHODS

An exploratory study was conducted within a longitudinal observational study. Eighteen older adults (mean age 86.7 years (SD: 3.2); 8 men; 15 MCI), participated. Lifespace metrics were generated from geolocation data (GPS and Bluetooth beacon) collected through a smartphone application for one week (2015-2016). Cognitive and mobility-related outcomes were compared from study data sets at baseline (2005-2007) and 6-year follow-up (2011-2014).

RESULTS

Lifespace data could be collected from all participants, and metrics were generated including percentage of time at home, maximum distance from home, episodes of travel in a week, days in a week participants left home, lifespace area (daily, weekly and total), indoor lifespace (regions in the home/hour), and a developed lifespace score that combined time, frequency of travel, distance and area. Results indicated a large range of lifespace areas (0.1 - 97.88 km² ; median 6.77 km² ) with similar patterns across lifespace metrics. Significant relationships were found between lifespace metrics and concurrent driving status and anteceding scores on the sit-to-stand test (at baseline and follow-up).

CONCLUSIONS

Further longitudinal exploration of lifespace is required to develop an understanding of the nature of lifespace of older community-dwelling people, and its relationship with health, mobility and well-being outcomes.

Change in GPS-assessed walking locations following a cluster-randomized controlled physical activity trial in older adults, results from the MIPARC trial

This study employed novel GPS methods to assess the effect of a multilevel physical activity (PA) intervention on device-measured walking locations in 305 community dwelling older adults, ages 65+ (mean age = 83, 73% women). Retirement communities were randomized to a 1-year PA intervention that encouraged neighborhood walking, or to a healthy aging control condition. Total time and time spent walking in four life-space domains were assessed using GPS and accelerometer devices. The intervention increased the time spent walking as a proportion of total time spent in the Campus, Neighborhood and Beyond Neighborhood domains. Intervention effects on walking location were observed in both genders and across physical and cognitive functioning groups. Results demonstrate that an intervention providing individual, social and environmental support for walking can increase PA in larger life-space domains for a broad spectrum of older adults.

Long-term digital device-enabled monitoring of functional status: Implications for management of persons with Alzheimer's disease

INTRODUCTION

Informal caregiving is an essential element of health-care delivery. Little data describes how caregivers structure care recipients' lives and impact their functional status.

METHODS

We performed observational studies of community dwelling persons with dementia (PWD) to measure functional status by simultaneous assessment of physical activity (PA) and lifespace (LS). We present data from two caregiver/care-recipient dyads representing higher and average degrees of caregiver involvement.

RESULTS

We acquired >42,800 (subject 1); >41,300 (subject 2) PA data points and >154,500 (subject 1); >119,700 (subject 2) LS data points over 15 months of near continuous observation. PA and LS patterns provided insights into the caregiver's role in structuring the PWD's day-to-day function and change in function over time.

DISCUSSION

We show that device-enabled functional monitoring (FM) can successfully gather and display data at resolutions required for dementia care studies. Objective quantification of individual caregiver/care-recipient dyads provides opportunities to implement patient-centered care.

Impact of deep brain stimulation on people with Parkinson's disease: A mixed methods feasibility study exploring lifespace and community outcomes

Background

Deep brain stimulation is a surgical treatment for Parkinson’s disease. Its impacts on motor symptoms are widely reported; however, little is known about the broader impact of deep brain stimulation on the community lives of people with Parkinson’s disease. Lifespace is a measure of lived community mobility, providing an indication of community access and participation.

Aims

This pilot study explored the feasibility of remotely monitoring the qualitative and quantitative community outcomes related to deep brain stimulation.

Methods

A longitudinal mixed methods study with a convergent design was undertaken exploring the lifespace, quality of life, life satisfaction and lived experiences of people with Parkinson’s disease before and after deep brain stimulation. Data were collected through questionnaires, semi-structured interviews and a smartphone-based application which collected geolocation data.

Results

Quantitative and qualitative data from eight participants living with Parkinson’s disease were analysed and integrated. At baseline, participants had a median age of 68 years and a median Hoehn and Yahr score of 2. Measuring a range of community-based outcomes indicated different change trajectories for individuals across outcomes. Key content areas were developed from the qualitative data: participation in occupations and travel and home. This study indicates the potential value of including geolocation data-based lifespace collection in metropolitan and regional areas.

Conclusions

Monitoring lifespace in conjunction with subjective measures provides insights into the complex and individually varied experiences. Further research could explore the impacts of deep brain stimulation on occupations and community participation to gain a deeper understanding of the related needs and support clinical approaches.

Considering high alcohol and violence neighborhood context using daily diaries and GPS: A pilot study among people living with HIV

Our understanding of how community-level context impacts care of persons living with HIV (PLWH), including antiretroviral therapy (ART) adherence and retention in care, is limited. The objective of this study was to characterize the activity spaces of PLWH from an urban area in Southeastern U.S., where the epidemic is among the nation's highest, and to examine how such activity spaces are associated with daily mood and health behaviors. In this small, pilot study, 11 participants were tracked with a global positioning system (GPS)-enabled application on their smartphones for 2 weeks. Activity spaces were created by connecting GPS points sequentially and adding buffers. Contextual exposure data (e.g., alcohol outlets) were connected to activity spaces. Participants also completed daily diary entry through texts 3 times per day regarding outcomes of substance use behaviors, mood, and medication adherence. This yielded a total of 18,007 GPS polyline records that we aggregated into 258 person-days that captured discrete occasions of exposure to contextual factors and subjects' behaviors and moods. On average, the participants spent 19% of their time awake during the 2-week periods in their residential census tract. Exposure to social and built environment factors such as alcohol outlets was greater when participants were outside versus inside their residential census tract. Exposures on daily routes were also significantly associated with ART adherence, alcohol consumption, and mood. Findings suggest substantial differences between activity spaces and residential contexts. Activity spaces are relevant for PLWH and may impact HIV care and behavioral outcomes such as ART adherence and substance use.

Physical Activity Barriers and Facilitators Among US Pacific Islanders and the Feasibility of Using Mobile Technologies for Intervention: A Focus Group Study With Tongan Americans

BACKGROUND

Pacific Islanders experience an elevated risk of health conditions such as obesity and diabetes, which are related to a lack of physical activity (PA). However, little attention has been paid to understanding the determinants of PA and promoting PA among this racial/ethnic group in the United States.

METHODS

We conducted focus group discussions with Tongan Americans, one of the major Pacific Islander groups in the United States, to gain a better understanding of their PA participation patterns, their barriers and facilitators, their attitudes toward PA, and their perceptions of how mobile technologies such as smartphones could help increase their PA levels.

RESULTS

Results indicate that although the participants understand the various benefits of PA, they do not engage in much leisure-time PA for exercise purposes. A lack of time is cited as an important reason for insufficient PA participation. In addition, most participants report familiarity with smartphones, positive views of mobile technology, and interest in using smartphones to measure and promote PA.

CONCLUSION

Multiple barriers were related with the low level of PA among Tongan Americans. Mobile technology is a promising way of enhancing PA among Tongan Americans and potentially other Pacific Islander subgroups. Culturally tailored strategies could significantly enhance the effectiveness of PA intervention.

Mobile Phone-Based Measures of Activity, Step Count, and Gait Speed: Results From a Study of Older Ambulatory Adults in a Naturalistic Setting

Background

Cellular mobile telephone technology shows much promise for delivering and evaluating healthcare interventions in cost-effective manners with minimal barriers to access. There is little data demonstrating that these devices can accurately measure clinically important aspects of individual functional status in naturalistic environments outside of the laboratory.

Objective

The objective of this study was to demonstrate that data derived from ubiquitous mobile phone technology, using algorithms developed and previously validated by our lab in a controlled setting, can be employed to continuously and noninvasively measure aspects of participant (subject) health status including step counts, gait speed, and activity level, in a naturalistic community setting. A second objective was to compare our mobile phone-based data against current standard survey-based gait instruments and clinical physical performance measures in order to determine whether they measured similar or independent constructs.

Methods

A total of 43 ambulatory, independently dwelling older adults were recruited from Nebraska Medicine, including 25 (58%, 25/43) healthy control individuals from our Engage Wellness Center and 18 (42%, 18/43) functionally impaired, cognitively intact individuals (who met at least 3 of 5 criteria for frailty) from our ambulatory Geriatrics Clinic. The following previously-validated surveys were obtained on study day 1: (1) Late Life Function and Disability Instrument (LLFDI); (2) Survey of Activities and Fear of Falling in the Elderly (SAFFE); (3) Patient Reported Outcomes Measurement Information System (PROMIS), short form version 1.0 Physical Function 10a (PROMIS-PF); and (4) PROMIS Global Health, short form version 1.1 (PROMIS-GH). In addition, clinical physical performance measurements of frailty (10 foot Get up and Go, 4 Meter walk, and Figure-of-8 Walk [F8W]) were also obtained. These metrics were compared to our mobile phone-based metrics collected from the participants in the community over a 24-hour period occurring within 1 week of the initial assessment.

Results

We identified statistically significant differences between functionally intact and frail participants in mobile phone-derived measures of percent activity (P=.002, t test), active versus inactive status (P=.02, t test), average step counts (P<.001, repeated measures analysis of variance [ANOVA]) and gait speed (P<.001, t test). In functionally intact individuals, the above mobile phone metrics assessed aspects of functional status independent (Bland-Altman and correlation analysis) of both survey- and/or performance battery-based functional measures. In contrast, in frail individuals, the above mobile phone metrics correlated with submeasures of both SAFFE and PROMIS-GH.

Conclusions

Continuous mobile phone-based measures of participant community activity and mobility strongly differentiate between persons with intact functional status and persons with a frailty phenotype. These measures assess dimensions of functional status independent of those measured using current validated questionnaires and physical performance assessments to identify functional compromise. Mobile phone-based gait measures may provide a more readily accessible and less-time consuming measure of gait, while further providing clinicians with longitudinal gait measures that are currently difficult to obtain.

Extended, continuous measures of functional status in community dwelling persons with Alzheimer's and related dementia: Infrastructure, performance, tradeoffs, preliminary data, and promise

BACKGROUND

The past decades have seen phenomenal growth in the availability of inexpensive and powerful personal computing devices. Efforts to leverage these devices to improve health care outcomes promise to remake many aspects of healthcare delivery, but remain in their infancy.

NEW METHOD

We describe the development of a mobile health platform designed for daily measures of functional status in ambulatory, community dwelling subjects, including those who have Alzheimer's disease or related neurodegenerative disorders. Using Smartwatches and Smartphones we measure subject overall activity and outdoor location (to derive their lifespace). These clinically-relevant measures allow us to track a subject's functional status in their natural environment over prolonged periods of time without repeated visits to healthcare providers. Functional status metrics are integrated with medical information and caregiver reports, which are used by a caregiving team to guide referrals for physician/APRN/NP care. COMPARISON: with Existing Methods We describe the design tradeoffs involved in all aspects of our current system architecture, focusing on decisions with significant impact on system cost, performance, scalability, and user-adherence.

RESULTS

We provide real-world data from current subject enrollees demonstrating system accuracy and reliability.

CONCLUSIONS

We document real-world feasibility in a group of men and women with dementia that Smartwatches/Smartphones can provide long-term, relevant clinical data regarding individual functional status. We describe the underlying considerations of this system so that interested organizations can adapt and scale our approach to their needs. Finally, we provide a potential agenda to guide development of future systems.

Addressing location uncertainties in GPS-based activity monitoring: A methodological framework

Location uncertainty has been a major barrier in information mining from location data. Although the development of electronic and telecommunication equipment has led to an increased amount and refined resolution of data about individuals' spatio-temporal trajectories, the potential of such data, especially in the context of environmental health studies, has not been fully realized due to the lack of methodology that addresses location uncertainties. This article describes a methodological framework for deriving information about people's continuous activities from individual-collected Global Positioning System (GPS) data, which is vital for a variety of environmental health studies. This framework is composed of two major methods that address critical issues at different stages of GPS data processing: (1) a fuzzy classification method for distinguishing activity patterns; and (2) a scale-adaptive method for refining activity locations and outdoor/indoor environments. Evaluation of this framework based on smartphone-collected GPS data indicates that it is robust to location errors and is able to generate useful information about individuals' life trajectories.

Classifying Human Activity Patterns from Smartphone Collected GPS data: a Fuzzy Classification and Aggregation Approach

Smartphones have emerged as a promising type of equipment for monitoring human activities in environmental health studies. However, degraded location accuracy and inconsistency of smartphone-measured GPS data have limited its effectiveness for classifying human activity patterns. This study proposes a fuzzy classification scheme for differentiating human activity patterns from smartphone-collected GPS data. Specifically, a fuzzy logic reasoning was adopted to overcome the influence of location uncertainty by estimating the probability of different activity types for single GPS points. Based on that approach, a segment aggregation method was developed to infer activity patterns, while adjusting for uncertainties of point attributes. Validations of the proposed methods were carried out based on a convenient sample of three subjects with different types of smartphones. The results indicate desirable accuracy (e.g., up to 96% in activity identification) with use of this method. Two examples were provided in the appendix to illustrate how the proposed methods could be applied in environmental health studies. Researchers could tailor this scheme to fit a variety of research topics.

Generating GPS activity spaces that shed light upon the mobility habits of older adults: a descriptive analysis

Background

Measuring mobility is critical for understanding neighborhood influences on older adults’ health and functioning. Global Positioning Systems (GPS) may represent an important opportunity to measure, describe, and compare mobility patterns in older adults.

Methods

We generated three types of activity spaces (Standard Deviation Ellipse, Minimum Convex Polygon, Daily Path Area) using GPS data from 95 older adults in Vancouver, Canada. Calculated activity space areas and compactness were compared across sociodemographic and resource characteristics.

Results

Area measures derived from the three different approaches to developing activity spaces were highly correlated. Participants who were younger, lived in less walkable neighborhoods, had a valid driver’s license, had access to a vehicle, or had physical support to go outside of their homes had larger activity spaces. Mobility space compactness measures also differed by sociodemographic and resource characteristics.

Conclusions

This research extends the literature by demonstrating that GPS tracking can be used as a valuable tool to better understand the geographic mobility patterns of older adults. This study informs potential ways to maintain older adult independence by identifying factors that influence geographic mobility.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-072X-13-51) contains supplementary material, which is available to authorized users.