Dustin T. Duncan

Health App Use Among US Mobile Phone Owners: A National Survey

Background Mobile phone health apps may now seem to be ubiquitous, yet much remains unknown with regard to their usage. Information is limited with regard to important metrics, including the percentage of the population that uses health apps, reasons for adoption/nonadoption, and reasons for noncontinuance of use. Objective The purpose of this study was to examine health app use among mobile phone owners in the United States. Methods We conducted a cross-sectional survey of 1604 mobile phone users throughout the United States. The 36-item survey assessed sociodemographic characteristics, history of and reasons for health app use/nonuse, perceived effectiveness of health apps, reasons for stopping use, and general health status. Results A little over half (934/1604, 58.23%) of mobile phone users had downloaded a health-related mobile app. Fitness and nutrition were the most common categories of health apps used, with most respondents using them at least daily. Common reasons for not having downloaded apps were lack of interest, cost, and concern about apps collecting their data. Individuals more likely to use health apps tended to be younger, have higher incomes, be more educated, be Latino/Hispanic, and have a body mass index (BMI) in the obese range (all P<.05). Cost was a significant concern among respondents, with a large proportion indicating that they would not pay anything for a health app. Interestingly, among those who had downloaded health apps, trust in their accuracy and data safety was quite high, and most felt that the apps had improved their health. About half of the respondents (427/934, 45.7%) had stopped using some health apps, primarily due to high data entry burden, loss of interest, and hidden costs. Conclusions These findings suggest that while many individuals use health apps, a substantial proportion of the population does not, and that even among those who use health apps, many stop using them. These data suggest that app developers need to better address consumer concerns, such as cost and high data entry burden, and that clinical trials are necessary to test the efficacy of health apps to broaden their appeal and adoption.

Validation of Walk Score ® for Estimating Neighborhood Walkability: An Analysis of Four US Metropolitan Areas

Neighborhood walkability can influence physical activity. We evaluated the validity of Walk Score® for assessing neighborhood walkability based on GIS (objective) indicators of neighborhood walkability with addresses from four US metropolitan areas with several street network buffer distances (i.e., 400-, 800-, and 1,600-meters). Address data come from the YMCA-Harvard After School Food and Fitness Project, an obesity prevention intervention involving children aged 5–11 years and their families participating in YMCA-administered, after-school programs located in four geographically diverse metropolitan areas in the US (n = 733). GIS data were used to measure multiple objective indicators of neighborhood walkability. Walk Scores were also obtained for the participant’s residential addresses. Spearman correlations between Walk Scores and the GIS neighborhood walkability indicators were calculated as well as Spearman correlations accounting for spatial autocorrelation. There were many significant moderate correlations between Walk Scores and the GIS neighborhood walkability indicators such as density of retail destinations and intersection density (p < 0.05). The magnitude varied by the GIS indicator of neighborhood walkability. Correlations generally became stronger with a larger spatial scale, and there were some geographic differences. Walk Score® is free and publicly available for public health researchers and practitioners. Results from our study suggest that Walk Score® is a valid measure of estimating certain aspects of neighborhood walkability, particularly at the 1600-meter buffer. As such, our study confirms and extends the generalizability of previous findings demonstrating that Walk Score is a valid measure of estimating neighborhood walkability in multiple geographic locations and at multiple spatial scales.

Safe To Walk? Neighborhood Safety and Physical Activity Among Public Housing Residents

Background Despite its health benefits, physical inactivity is pervasive, particularly among those living in lower-income urban communities. In such settings, neighborhood safety may impact willingness to be regularly physically active. We examined the association of perceived neighborhood safety with pedometer-determined physical activity and physical activity self-efficacy. Methods and Findings Participants were 1,180 predominantly racial/ethnic minority adults recruited from 12 urban low-income housing complexes in metropolitan Boston. Participants completed a 5-d pedometer data-collection protocol and self-reported their perceptions of neighborhood safety and self-efficacy (i.e., confidence in the ability to be physically active). Gender-stratified bivariate and multivariable random effects models were estimated to account for within-site clustering. Most participants reported feeling safe during the day, while just over one-third (36%) felt safe at night. We found no association between daytime safety reports and physical activity among both men and women. There was also no association between night-time safety reports and physical activity among men (p = 0.23) but women who reported feeling unsafe (versus safe) at night showed significantly fewer steps per day (4,302 versus 5,178, p = 0.01). Perceiving ones neighborhood as unsafe during the day was associated with significantly lower odds of having high physical activity self-efficacy among both men (OR 0.40, p = 0.01) and women (OR 0.68, p = 0.02). Conclusions Residing in a neighborhood that is perceived to be unsafe at night is a barrier to regular physical activity among individuals, especially women, living in urban low-income housing. Feeling unsafe may also diminish confidence in the ability to be more physically active. Both of these factors may limit the effectiveness of physical activity promotion strategies delivered in similar settings.

Disparities in youth physical activity in the United States: 2003-2006.

PURPOSE This study aimed to examine changes in physical activity among children and adolescents, by race/ethnicity, in the United States from 2003-2004 to 2005-2006. METHODS Secondary analysis of the objectively measured accelerometer data among children and adolescents 6-19 yr: 2003-2004 (n = 1665) and 2005-2006 (n = 1716) from the nationally representative National Health and Nutrition Examination Survey 2003-2004 and 2005-2006. We estimated regression coefficients for change between the two periods by age group, accounting for sampling design and adjusting for age, sex, race/ethnicity, and number of hours monitored. We tested for differences in mean accelerometer counts per minute and minutes per day of moderate and vigorous physical activity trends by race/ethnicity and gender. RESULTS Physical activity decreased with age, boys were more active than girls, and non-Hispanic black children were more active than non-Hispanic whites (all P < 0.01). Overall mean accelerometer counts increased from 2003-2004 to 2005-2006 for children ages 6-11 yr (+31.6 counts per minute; 95% confidence interval = 0.51-62.6) but not among adolescents ages 12-19 yr. There was an increase over time in mean accelerometer counts among 6- to 11-yr-old non-Hispanic white children (+52.4 counts per minute, P = 0.007; 95% confidence interval = 15.7-89) but a decrease among non-Hispanic black and Mexican American children. No changes over the period in moderate and vigorous physical activity were found in either age group. CONCLUSIONS The lack of improvement in physical activity among all children and adolescents and a potentially emerging race-ethnic disparity indicate a need for further research on potential mechanisms underlying these differences. Effective interventions to improve physical activity opportunities and attenuate the decline in activity levels as children enter adolescence are needed.

Geosocial-Networking App Usage Patterns of Gay, Bisexual, and Other Men Who Have Sex With Men: Survey Among Users of Grindr, A Mobile Dating App.

Background Geosocial-networking apps like Grindr have been used increasingly among men who have sex with men (MSM) to meet anonymous partners. These mobile dating apps employ global positioning system technology to facilitate connections with other users based on their current location. These new technologies have generated quicker and easier modes for men who have sex with men to meet potential partners based on attraction and physical proximity. Objective The aim of this study is to describe geosocial-networking app use and recent sexual behaviors of MSM in the Atlanta metropolitan statistical area. Methods Our sample was recruited from Grindr, the most commonly used of these mobile apps among MSM, using broadcast advertising. Advertisements were displayed over the course of a 72-hour period and participants were directed to a Web-based survey. Results In total, 604 men clicked through the advertisement, and 92 users completed the survey. One-third (38.0%) of the men reported using these mobile apps to meet new sexual partners, and one-fifth (18.5%) used them to “kill time” when bored. Men reporting currently being in a relationship were less likely to report using these mobile apps to meet other MSM to date or to find a boyfriend or romantic partner, but more likely to report using these mobile apps to meet other MSM to have sex, X 2 24=12.1, P=.016. Respondents had current accounts on 3.11 mobile apps (SD 1.84) on average, with Grindr being the most common (100%), followed by Scruff (52.5%), and Jack’d (45.7%). Most men were most active in the late night (40.2%), and on weekdays (64.1%). Each day, on average, men reported opening these mobile apps 8.38 times (SD 8.10) and spent 1.31 hours (SD 1.15) on these mobile apps. The age respondents began using these mobile apps was associated with the age at their first instance of insertive anal sex (r80=.527, P<.001) and receptive anal sex (r76=.527, P<.001). Conclusions These findings suggest that MSM use multiple mobile apps and spend significant time on them. For these reasons, HIV prevention interventions could be delivered on these mobile apps.

Racial differences in the built environment—body mass index relationship? A geospatial analysis of adolescents in urban neighborhoods

BackgroundBuilt environment features of neighborhoods may be related to obesity among adolescents and potentially related to obesity-related health disparities. The purpose of this study was to investigate spatial relationships between various built environment features and body mass index (BMI) z-score among adolescents, and to investigate if race/ethnicity modifies these relationships. A secondary objective was to evaluate the sensitivity of findings to the spatial scale of analysis (i.e. 400- and 800-meter street network buffers).MethodsData come from the 2008 Boston Youth Survey, a school-based sample of public high school students in Boston, MA. Analyses include data collected from students who had georeferenced residential information and complete and valid data to compute BMI z-score (n = 1,034). We built a spatial database using GIS with various features related to access to walking destinations and to community design. Spatial autocorrelation in key study variables was calculated with the Global Moran’s I statistic. We fit conventional ordinary least squares (OLS) regression and spatial simultaneous autoregressive error models that control for the spatial autocorrelation in the data as appropriate. Models were conducted using the total sample of adolescents as well as including an interaction term for race/ethnicity, adjusting for several potential individual- and neighborhood-level confounders and clustering of students within schools.ResultsWe found significant positive spatial autocorrelation in the built environment features examined (Global Moran’s I most ≥ 0.60; all p = 0.001) but not in BMI z-score (Global Moran’s I = 0.07, p = 0.28). Because we found significant spatial autocorrelation in our OLS regression residuals, we fit spatial autoregressive models. Most built environment features were not associated with BMI z-score. Density of bus stops was associated with a higher BMI z-score among Whites (Coefficient: 0.029, p < 0.05). The interaction term for Asians in the association between retail destinations and BMI z-score was statistically significant and indicated an inverse association. Sidewalk completeness was significantly associated with a higher BMI z-score for the total sample (Coefficient: 0.010, p < 0.05). These significant associations were found for the 800-meter buffer.ConclusionSome relationships between the built environment and adolescent BMI z-score were in the unexpected direction. Our findings overall suggest that the built environment does not explain a large proportion of the variation in adolescent BMI z-score or racial disparities in adolescent obesity. However, there are some differences by race/ethnicity that require further research among adolescents.

Creating a Youth Violence Data System for Boston, Massachusetts

Abstract The Harvard Youth Violence Prevention Center has partnered with the city of Boston, Massachusetts to create a data system to track youth violence. The system provides continuing information about fighting, bullying, dating violence and gun carrying. Data from it show that many Boston adolescents are afraid on public transportation (as compared to home, school or street) and that most students widely overestimate the number of their classmates carrying guns. The system also provides data on neighbourhood variables such as collective efficacy. The system has been a success due to the mutual respect shown between the academic and city partners, and the mutual benefits it provides to both.

Change in Misperception of Child's Body Weight among Parents of American Preschool Children

BACKGROUND Little is known about parental recognition of their childs overweight status over time. The aim of this study was to examine the prevalence of parental misperceptions related to preschool childrens weight in the last two decades. METHODS Data come from the National Health and Nutrition Examination Survey from 1988 to 1994 (early survey; n=3839) and 2007 to 2012 (recent survey; n=3153). Parents were asked whether they considered their child, ages 2-5 years, to be overweight, underweight, or just about the right weight. We estimated the probability ratio (PR) between the two surveys for parents perceiving their overweight child as overweight. RESULTS Percentages of parents who inappropriately perceived their overweight child as just about the right weight was 96.6% and 94.9% for the early and recent survey, respectively. As high as 78.4% of parents perceived their obese child as just about the right weight in the recent survey. The probability of overweight/obese children being perceived as overweight in the early survey was 0.18 (95% confidence interval [CI]=0.14-0.22) and further lowered to 0.14 (95% CI=0.11-0.17) in the recent survey. After adjustment for sociodemographics and BMI z-scores of directly measured body weight, probability of being appropriately perceived by the parents declined by 30% between surveys (PR=0.70 [0.63, 0.78]). CONCLUSIONS There was a declining tendency among parents to perceive overweight children appropriately. Strategies are needed to explore how to encourage clinician discussions with parents about appropriate weight for their child and strengthen capacity for childhood obesity prevention.

HIV Risk Behaviors, Perceptions, and Testing and Preexposure Prophylaxis (PrEP) Awareness/Use in Grindr-Using Men Who Have Sex With Men in Atlanta, Georgia

&NA; Geosocial‐networking smartphone applications such as Grindr can help men who have sex with men (MSM) meet sexual partners. Given the high incidence of HIV in the Deep South, the purpose of our study was to assess HIV risk and preexposure prophylaxis (PrEP) awareness and use in a sample of HIV‐uninfected, Grindr‐using MSM residing in Atlanta, Georgia (n = 84). Most (n = 71; 84.6%) reported being somewhat or very concerned about becoming HIV infected. Most (n = 74; 88.1%) had been tested for HIV in their lifetimes. About three fourths (n = 65; 77.4%) were aware of PrEP, but only 11.9% currently used the medication. HIV continues to disproportionately impact MSM and represents a significant source of concern. As the number of new infections continues to rise, it is important to decrease risks associated with acquisition and transmission of HIV by increasing rates of HIV testing and the use of biobehavioral interventions such as PrEP.

Differential accuracy of physical activity self-report by body mass index.

OBJECTIVES To examine whether agreement between self-reported and accelerometer-measured physical activity varies by BMI category in a low-income black sample. METHODS Participants completed a questionnaire and wore an accelerometer for 4-6 days. Using one- and 10-minute bouts, accelerometers measured light, moderate, and vigorous physical activity time. RESULTS Correlations varied by obesity (nonobese: one-minute r=0.41; 10-minute r=0.47; obese: one-minute r=0.21; 10-minute r=0 .14). Agreement was highest among nonobese persons (one-minute kappa = 0.48, 10-minute kappa = 0.023; obese: one-minute kappa = -0.024, 10- minute kappa = -0.020). CONCLUSIONS We found compromised questionnaire performance among obese participants.