Jacqueline Kerr's research while affiliated with University of California, San Diego and other places

Publications (280)

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Background A better understanding of the extent to which psychosocial and environmental correlates of physical activity are specific to locations would inform intervention optimization. Purpose To investigate cross-sectional associations of location-general and location-specific variables with physical activity and sedentary time in three common l...
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Introduction Built and natural environments may provide opportunities for physical activity. However, studies are limited by primarily using residential addresses to define exposure and self-report to measure physical activity. We quantified associations between global positioning systems (GPS)-based activity space measures of environmental exposur...
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Older adults with obesity spend the majority of their waking hours sedentary. Given substantial barriers to regular physical activity in this population, approaches to reduce sedentary time could be an effective health promotion strategy. We present the protocol of a randomized controlled trial to reduce sitting time in older adults with a body mas...
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As the U.S. population ages, communities must adapt to help older adults thrive. Built environment features, like safe sidewalks and crosswalks, provide the foundation for age- and physical activity-friendly communities. Controlled studies are needed to evaluate advocacy training programs that instruct and support seniors to advocate for more walka...
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Objective: To evaluate whether sedentary time (ST) and/or sedentary behavior patterns are related to incident diabetes in the U.S.'s oldest age-groups. Research design and methods: Women without physician-diagnosed diabetes (n = 4,839, mean ± SD age = 79 ± 7 years) wore accelerometers for ≥4 days and were followed up to 6 years for self-reported...
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Background Investigation of physical activity and dietary behaviors across locations can inform “setting-specific” health behavior interventions and improve understanding of contextual vulnerabilities to poor health. This study examined how physical activity, sedentary time, and dietary behaviors differed across home, school, and other locations in...
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Background: The authors tested the efficacy of the "I-STAND" intervention for reducing sitting time, a novel and potentially health-promoting approach, in older adults with obesity. Methods: The authors recruited 60 people (mean age = 68 ± 4.9 years, 68% female, 86% White; mean body mass index = 35.4). The participants were randomized to receive...
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Creating more physical activity–supportive built environments is recommended by the World Health Organization for controlling noncommunicable diseases. The IPEN (International Physical Activity and Environment Network) Adult Study was undertaken to provide international evidence on associations of built environments with physical activity and weigh...
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Purpose: To test the validity of the Ecological Video Identification of Physical Activity (EVIP) computer vision algorithms for automated video-based ecological assessment of physical activity in settings such as parks and schoolyards. Methods: 27 hours of video were collected from stationary overhead video cameras across 22 visits in 9 sites ca...
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Background Sedentary behavior is pervasive, especially in older adults, and is associated with cardiometabolic disease and mortality. Relationships between cardiometabolic biomarkers and sitting time are unexplored in older women, as are possible ethnic differences. Methods and Results Ethnic differences in sitting behavior and associations with c...
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Using neighborhood open spaces (NOS) may be an easy way for older adults to maintain healthy aging through physical activity and social interaction. Little is known about older adults’ use of NOS, their preferences, and barriers to using them. This paper presents older adults’ use of NOS in a deprived neighborhood before and after an intervention a...
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The study aimed to examine associations of neighborhood built environments and proximity of food outlets (BE measures) with body weight status using pooled data from an international study (IPEN Adult). Objective BE measures were calculated using geographic information systems for 10,008 participants (4463 male, 45%) aged 16-66 years in 14 cities....
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Study Objectives Activities throughout the day, including sleep, sedentary behavior (SB), light physical activity (LIPA), and moderate to vigorous physical activity (MVPA) are independently associated with cardiometabolic health. Few studies have examined interrelationships between sleep and 24-hour activity and associations with cardiometabolic ri...
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Background: To examine relations between parents' perceived neighborhood recreation environments and multiple measures of adolescent physical activity (PA). Methods: Participants (N = 928; age 14.1 [1.4] y, 50.4% girls, and 33.4% nonwhite/Hispanic) and their parents were recruited. Teen moderate to vigorous PA (MVPA) was assessed with 7-day acce...
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Background Evidence suggests that short and long sleep durations are potential lifestyle factors associated with cardiovascular disease (CVD). Research on sleep duration and CVD risk is limited by use of self-report sleep measures, homogeneous populations, and studies on individual CVD risk factors. For women, risk of CVD and inadequate sleep durat...
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Background and Hypothesis: Extracellular vesicles (EVs) are membrane-bound particles shed from a variety of cell types. They contain molecular cargo from the parent cell including metabolites, proteins, and nucleic acids. EVs are present in biofluids and could be promising biomarkers for monitoring wellness. Total sedentary time is linearly associa...
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Age-related decreases in cerebral blood flow (CBF) may lead to cognitive decline, while physical activity (PA) can maintain CBF and cognition in aging. The intensity of PA needed to affect CBF in aging, and the independent effects of sedentary time on CBF are currently unknown. Moreover, research conducted in free-living environments with objective...
Chapter
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Research concerning how the built environment impacts behaviors linked to breast cancer has become of increased interest to public health researchers. Physical activity is a modifiable behavioral factor that can reduce breast cancer risk, cancer recurrence risk, and improve treatment effects by targeting biological mechanisms such as insulin resist...
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Neighborhood Open Spaces (NOS) such as public spaces around people’s homes, parks and village greens, may support activity and socializing for older adults. These spaces might be especially important for older adults as they typically are less mobile and have smaller activity spaces and social networks than other age groups. The present exploratory...
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Objectives: Independently, physical activity (PA), sedentary behavior (SB), and sleep are related to the development and progression of chronic diseases. Less is known about how rest-activity behaviors cluster within individuals and how rest-activity behavior profiles relate to health. In this study we aimed to investigate if adult women cluster i...
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This study compared five different methods for analyzing accelerometer-measured physical activity (PA) in older adults and assessed the relationship between changes in PA and changes in physical function and depressive symptoms for each method. Older adult females (N = 144, Mage = 83.3 ± 6.4yrs) wore hip accelerometers for six days and completed me...
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Objectives: We aimed to quantify the agreement between self-report, standard cut-point accelerometer, and machine learning accelerometer estimates of physical activity (PA), and exam- ine how agreement changes over time among older adults in an intervention setting. Methods: Data were from a randomized weight loss trial that encouraged increased PA...
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Objective: To parameterize and validate two existing algorithms for identifying out-of-bed time using 24 h hip-worn accelerometer data from older women. Approach: Overall, 628 women (80 ± 6 years old) wore ActiGraph GT3X+ accelerometers 24 h d-1 for up to 7 d and concurrently completed sleep-logs. Trained staff used a validated visual analysis p...
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Improving sedentary measurement is critical to understanding sedentary-health associations in youth. This study assessed agreement between the thigh-worn activPAL and commonly used hip-worn ActiGraph accelerometer methods for assessing sedentary patterns in children. Both devices were worn by 8–12-year-olds (N = 195) for 4.6 ± 1.9 days. Two ActiGra...
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Accelerometers are person-worn sensors that provide objective measurements of movement based on minute-level activity counts, thus providing a rich framework for assessing physical activity patterns. New statistical approaches and computational tools are needed to exploit these densely sampled time-series data. We implement a functional principal c...
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Objective: The authors investigated if the physical activity increases observed in the Multilevel Intervention for Physical Activity in Retirement Communities (MIPARC) improved cognitive functions in older adults. The authors also examined if within-person changes in moderate to vigorous physical activity (MVPA), as opposed to low-light and high-l...
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PurposeTo examine associations between dimensions of sedentary behavior and cognitive function in breast cancer survivors. Methods Sedentary behavior variables were measured using thigh-worn activPALs, and included total daily sitting time, time in long sitting bouts, sit-to-stand transitions, and standing time. Cognitive function was assessed usin...
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Background: Sleep, sedentary behavior (SB), and physical activity (PA) are independently associated with cardiometabolic health, but few studies have examined the interrelationships between 24 hour activity and cardiometabolic risk factors. Extending sleep may be a feasible cardiometabolic risk reduction strategy; however, research is needed to und...
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Less is known about how neighborhood environments relate to sedentary time as compared to physical activity. This study examined relations of perceived and objective neighborhood environments with TV time, total screen time, total sedentary time, sedentary time at home, sedentary time in the home neighborhood, and time spent at home, in 524 12-16 y...
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Background: Evidence that higher sedentary time is associated with higher risk for cardiovascular disease (CVD) is based mainly on self-reported measures. Few studies have examined whether patterns of sedentary time are associated with higher risk for CVD. Methods: Women from the Objective Physical Activity and Cardiovascular Health (OPACH) Stud...
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Background Physical inactivity and unhealthy diet are modifiable behaviors that lead to several cancers. Biologically, these behaviors are linked to cancer through obesity-related insulin resistance, inflammation, and oxidative stress. Individual strategies to change physical activity and diet are often short lived with limited effects. Interventio...
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Background: Postmenopausal Latinas are a growing population group in the US who are at high risk for cardiovascular disease. Epidemiological studies have shown that excessive sitting is related to cardiovascular disease risk. Older women sit for prolonged periods and most individuals do not meet physical activity guidelines. Reducing sitting throu...
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Background: For breast cancer survivors, moderate to vigorous physical activity (MVPA) is associated with improved survival. Less is known about the interrelationships of daytime activities (sedentary behavior [SB], light-intensity physical activity, and MVPA) and associations with survivors' health outcomes. This study will use isotemporal substi...
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Research is needed on interventions targeting sedentary behavior with appropriate behavior-change tools. The current study used convergent sequential mixed methods (QUAN + qual) to explore tool use during a edentary behavior intervention. Data came from a two-arm randomized sedentary behavior pilot intervention. Participants used a number of interv...
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Less than 3% of older adults meet physical activity (PA) guidelines. Our previous project, Multilevel Intervention for Physical Activity in Retirement Communities (MIPARC), increased participants’ steps; however, transitioning leadership from UCSD staff to the community failed. Therefore, we launched the Peer Empowerment Program for PA (PEP4PA), wh...
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Background: Prolonged sitting is associated with adverse aging-related outcomes. Few interventions have tested whether sitting patterns can be altered in older adults with obesity. We tested the impacts of a sitting reduction intervention (I-STAND) in a pilot randomized controlled trial. Methods: Participants (N = 60, mean age = 68.4, 68% female, 8...
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Objectives: To document challenges to and benefits from research involving the use of images by capturing examples of such research to assess physical activity- or nutrition-related behaviors and/or environments. Methods: Researchers (i.e., key informants) using image capture in their research were identified through knowledge and networks of th...
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Purpose: Sleep disturbances are associated with poor health outcomes in older adults. The Patient-Reported Outcomes Information System (PROMIS) Sleep Disturbance Scale was designed to assess self-reported general sleep and sleep disturbance. The objective of this study was to validate the short-form PROMIS Sleep Disturbance Scale for use among old...
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This paper reports on the findings and recommendations specific to older adults from the "Tech Summit: Innovative Tools for Assessing Diet and Physical Activity for Health Promotion" forum organized by the North American branch of the International Life Sciences Institute. The summit aimed to investigate current and emerging challenges related to i...
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This article explores the role of the work environment in determining physical activity gained within and around the workplace. With most adults spending more than half of their waking day at work, the workplace is a promising venue for promoting physical activity. We used a sample of 147 employed women—median age = 53 years old; 42% meeting Center...
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Obesity and its impact on health is a multifaceted phenomenon encompassing many factors, including demographics, environment, lifestyle, and psychosocial functioning. A systems science approach, investigating these many influences, is needed to capture the complexity and multidimensionality of obesity prevention to improve health. Leveraging baseli...
Data
Anonymized partial Reach for Health cohort participant information. (CSV)
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Since 1980, many studies have evaluated whether stair-use prompts increased physical activity by quantifying changes in stair use. To more completely evaluate changes in physical activity, this study addressed the often-overlooked assessment of climbing up escalators by evaluating the degree to which stair-use sign prompts increased active ascent—d...
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Purpose The aim of the present study was to examine the convergent validity of two commonly-used accelerometers for estimating time spent in various physical activity intensities in adults. Methods The sample comprised 37 adults (26 males) with a mean (SD) age of 37.6 (12.2) years from San Diego, USA. Participants wore ActiGraph GT3X+ and Actical...
Article
Purpose: To investigate whether adolescents cluster into profiles based on where they accumulate moderate-to-vigorous physical activity (MVPA), if overall MVPA differs across profiles, and if walking to school and participant and neighborhood characteristics explain profile membership. Methods: Adolescents (N=528; mean age=14.12±1.44; 50% girls)...
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Background: This study investigated the effects of metformin and weight loss on biomarkers associated with breast cancer prognosis. Methods: Overweight/obese postmenopausal breast cancer survivors (n = 333) were randomly assigned to metformin vs placebo and to a weight loss intervention vs control (ie, usual care). The 2 × 2 factorial design all...
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Background We examined associations of sedentary time and sedentary accumulation patterns (i.e., how sedentary time is accumulated) with prevalent diabetes in an ethnically diverse cohort of older women. Methods Community-dwelling women aged 63-99 (n=6,116; median age=79) wore ActiGraph GT3X+ accelerometers 24 hours/day for up to seven days from w...
Preprint
BACKGROUND Image based data collection for obesity research is in its infancy. OBJECTIVE The present study aimed to document challenges to and benefits from such research by capturing examples of research involving the use of images to assess physical activity- or nutrition-related behaviors and/or environments. METHODS Researchers (i.e., key inf...
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Background: Older adults are the least active population group. Interventions in residential settings may support a multi-level approach to behavior change. Methods: In a cluster randomized control trial, 11 San Diego retirement communities were assigned to a physical activity (PA) intervention or a healthy aging attention control condition. Par...
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Background Neighborhood walkability has consistently been associated with utilitarian walking and total physical activity in non-European studies. However, evidence on environmental correlates of physical activity in Europe is still scarce and little is known about potential interactions between neighborhood walkability, active travel, and individu...
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Background: Recent epidemiological evidence indicates that, on average, people are sedentary for approximately 7.7 hours per day. There are deleterious effects of prolonged sedentary behavior that are separate from participation in physical activity and include increased risk of weight gain, cancer, metabolic syndrome, diabetes, and heart disease....
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Background: Cross-sectional and prospective studies have demonstrated that self-reported short sleep is a predictor of cardiometabolic conditions including obesity, Type 2 Diabetes, and cardiovascular events. The relationship may be non-linear, with short and long sleep related to markers of cardiometabolic risk. Research on sleep duration and card...
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Background: Evidence on sedentary behavior and cardiovascular disease (CVD) is largely based on self-reported sedentary time. Furthermore, how sedentary time is accumulated (in longer vs. shorter bouts) may be related to CVD risk but has not been tested. Methods: Women (n=5638, mean age=79±7) with no history of myocardial infarction or stroke wore...
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Daily mobility, defined as the ability to move oneself within one’s neighborhood and regions beyond, is an important construct, which affects people as they age. Having a feasible and valid measure of daily mobility is essential to understand how it affects older adults’ everyday life. Given the limitations of existing measures, new tools may be ne...
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Background Over 60% of Latinas report not meeting moderate to vigorous physical activity (MVPA) guidelines of 150 min/week. Ecological models of health posit that intrapersonal and environmental factors interact with one another to influence physical activity. Understanding their interactions in relation to transportation behaviors may inform inter...
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Background: Older adults have high rates of obesity and are prone to chronic health conditions. These conditions are in part due to high rates of sedentary time (ST). As such, reducing ST could be an innovative strategy for improving health outcomes among obese older adults. To test this theory, we developed a novel, technology-enhanced interventi...
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Purpose: To improve estimates of sitting time from hip worn accelerometers used in large cohort studies by employing machine learning methods developed on free living activPAL data. Methods: Thirty breast cancer survivors concurrently wore a hip worn accelerometer and a thigh worn activPAL for 7 days. A random forest classifier, trained on the a...
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Introduction: The study examined the association of neighborhood walkability to multiple activity-related outcomes and BMI among adolescents and evaluated socioeconomic status as an effect modifier. Method: Cross-sectional study, with adolescents recruited from neighborhoods that met criteria for a 2 × 2 matrix defined by high/low GIS-defined wa...
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Study purpose The integration of methods to assess daytime physical activity (PA) and sedentary behavior (SB) and nighttime sleep would allow the evaluation of 24-hour daily activity using a single device. Accelerometer devices used to assess daytime PA have not been substantially validated to evaluate sleep. The objective of this study was to use...
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Purpose: The present study examined various accelerometer nonwear definitions and their impact on detection of sedentary time using different ActiGraph models, filters, and axes. Methods: In total, 61 youth (34 children and 27 adolescents; aged 5-17 y) wore a 7164 and GT3X+ ActiGraph on a hip-worn belt during a 90-minute structured sedentary act...
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Collaboration between physical activity (PA) researchers and transport planners is a recommended strategy to combat the physical inactivity epidemic. Data collected by PA researchers could be used to identify, implement and evaluate active transport (AT) projects. However, despite aligned interests, researchers and transport planners rarely collabo...