Emergency Department Visits for Pedestrians Injured in Motor Vehicle Traffic Crashes - United States, January 2021-December 2023.

Traffic-related pedestrian deaths in the United States reached a 40-year high in 2021. Each year, pedestrians also suffer nonfatal traffic-related injuries requiring medical treatment. Near real-time emergency department visit data from CDC's National Syndromic Surveillance Program during January 2021-December 2023 indicated that among approximately 301 million visits identified, 137,325 involved a pedestrian injury (overall visit proportion = 45.62 per 100,000 visits). The proportions of visits for pedestrian injury were 1.53-2.47 times as high among six racial and ethnic minority groups as that among non-Hispanic White persons. Compared with persons aged ≥65 years, proportions among those aged 15-24 and 25-34 years were 2.83 and 2.61 times as high, respectively. The visit proportion was 1.93 times as high among males as among females, and 1.21 times as high during September-November as during June-August. Timely pedestrian injury data can help collaborating federal, state, and local partners rapidly monitor trends, identify disparities, and implement strategies supporting the Safe System approach, a framework for preventing traffic injuries among all road users.

Prevalence of vision zero action plans or strategies: USA, 2021.

BACKGROUND: Vision Zero is a strategy to eliminate traffic fatalities and to promote equitable mobility options for all road users. Using a nationally representative survey, we aimed to estimate the prevalence of Vision Zero action plans or strategies in the USA. METHODS: Municipal officials were surveyed in 2021. In this cross-sectional study, we calculated the prevalence of Vision Zero plans or strategies and compared municipalities with adjusted prevalence ratios (PR) to account for region and sociodemographic characteristics. RESULTS: Among 1955 municipalities participating in the survey (question-specific response rate: 44.3%), the prevalence of a Vision Zero action plan or strategy was 7.7%; 70.5% responded no and 21.8% don't know. Prevalence was 4.8% in small municipalities (1000-2499 residents), 20.3% in medium-large municipalities (50 000-124 999 residents; PR=4.1), and 37.8% in large municipalities (≥125 000 residents; PR=7.6). CONCLUSION: The prevalence of Vision Zero plans and strategies across the USA is low. Additional adoption of Vision Zero plans and strategies could help address traffic fatalities.

Leisure-time physical activity and mortality from influenza and pneumonia: a cohort study of 577 909 US adults.

OBJECTIVE: To examine the association of leisure-time physical activity with mortality from influenza and pneumonia. METHODS: A nationally representative sample of US adults (aged ≥18 years) who participated in the National Health Interview Survey from 1998 to 2018 were followed for mortality through 2019. Participants were classified as meeting both physical activity guidelines if they reported ≥150 min/week of moderate-intensity equivalent aerobic physical activity and ≥2 episodes/week of muscle-strengthening activity. Participants were also classified into five volume-based categories of self-reported aerobic and muscle-strengthening activity. Influenza and pneumonia mortality was defined as having an underlying cause of death with an International Classification of Diseases, 10th Revision code of J09-J18 recorded in the National Death Index. Mortality risk was assessed using Cox proportional hazards, adjusting for sociodemographic and lifestyle factors, health conditions and influenza and pneumococcal vaccination status. Data were analysed in 2022. RESULTS: Among 577 909 participants followed for a median of 9.23 years, 1516 influenza and pneumonia deaths were recorded. Compared with participants meeting neither guideline, those meeting both guidelines had 48% lower adjusted risk of influenza and pneumonia mortality. Relative to no aerobic activity, 10-149, 150-300, 301-600 and >600 min/week were associated with lower risk (by 21%, 41%, 50% and 41%). Relative to <2 episodes/week of muscle-strengthening activity, 2 episodes/week was associated with 47% lower risk and ≥7 episodes/week with 41% higher risk. CONCLUSIONS: Aerobic physical activity, even at quantities below the recommended level, may be associated with lower influenza and pneumonia mortality while muscle-strengthening activity demonstrated a J-shaped relationship.

Changes in Physical Inactivity Among US Adults Overall and by Sociodemographic Characteristics, Behavioral Risk Factor Surveillance System, 2020 Versus 2018.

The COVID-19 pandemic may have disrupted people's work-life patterns and access to places to be physically active. Behavioral Risk Factor Surveillance System data were analyzed to assess changes in self-reported leisure-time physical inactivity. The results showed that prevalence of inactivity among US adults decreased 0.7 percentage points (95% CI: -1.2 to -0.3), from 24.5% in 2018 to 23.8% in 2020, and the greatest decreases were observed among rural-dwelling women, rural-dwelling men, and non-Hispanic White women. These findings highlight a need to understand and address factors that lead to differential changes in leisure-time physical inactivity across subpopulations during public health emergencies.

Physical Activity-Friendly Policies and Community Design Features in the US, 2014 and 2021.

INTRODUCTION: The 2014 Community-Based Survey of Supports for Healthy Eating and Active Living documented the prevalence of US municipal policy and community design supports for physical activity. The survey was repeated in 2021. Our study examined change in the prevalence of supports from 2014 to 2021, overall and by municipality characteristic. METHODS: Municipalities were sampled independently each survey year. We calculated prevalence in 2014 and 2021 and the prevalence ratio (PR) for 15 supports covering zoning codes, park policies and budgets, design standards, Complete Streets policies, and shared use agreements. We used a Bonferroni-corrected Breslow-Day test to test for interaction by municipality characteristic. RESULTS: In 2014 (2,009 municipalities) compared with 2021 (1,882 municipalities), prevalence increased for several zoning codes: block sizes of walkable distances (PR = 1.46), minimum sidewalk width (PR = 1.19), pedestrian amenities along streets (PR = 1.15), continuous sidewalk coverage (PR = 1.14), and building orientation to pedestrian scale (PR = 1.08). Prevalence also increased for design standards requiring dedicated bicycle infrastructure for roadway expansion projects or street retrofits (PR = 1.19). Prevalence declined for shared use agreements (PR = 0.87). The prevalence gap widened between the most and least populous municipalities for Complete Streets policies (from a gap of 33.6 percentage points [PP] in 2014 to 54.0 PP in 2021) and for zoning codes requiring block sizes that were walkable distances (from 11.8 PP to 41.4 PP). CONCLUSION: To continue progress, more communities could consider adopting physical activity-friendly policies and design features.

Observation of and intention to use new places and changed spaces for physical activity during the COVID-19 pandemic - United States, June 2021.

The COVID-19 pandemic prompted built environment changes throughout the United States. We assessed the prevalence of new places and changed spaces for physical activity as observed by US adults and their intentions to use them. We used data from SummerStyles, a web-based survey of US adults conducted in June 2021 (n = 4073). Respondents were asked if they had discovered new places to be physically active during the past year, and if changes had been made to streets or outdoor areas to allow additional space for recreating. Those responding "yes" were asked if they intended to use the respective space. We estimated the weighted prevalence of adults who observed new places and changed spaces, and their intended use, by sociodemographic and geographic characteristics, physical activity level, and walking status. We compared subgroups with prevalence ratios (PR). Overall, 25.0% of US adults reported discovering new places for physical activity, and 25.3% reported changes to streets and outdoor spaces. Intention to use new places and changed spaces exceeded 50% among all sociodemographic and geographic subgroups. Among those reporting changes, adults who were physically inactive compared to those who were sufficiently active had similar intentions to use new places (PR = 0.83; 95% CI = 0.63, 1.10) and changed spaces (PR = 0.90; 95% CI = 0.69, 1.17). Approximately 1 in 4 adults reported discovering new places or changed spaces to support physical activity during the COVID-19 pandemic, and most intended to use these features. Expanding access to such supportive environments may help promote physical activity participation.

Telehealth and Public Health Practice in the United States-Before, During, and After the COVID-19 Pandemic.

Telehealth is the use of electronic information and telecommunication technologies to provide care when the patient and the provider are not in the same room at the same time. Telehealth accounted for less than 1% of all Medicare Fee-for-Service outpatient visits in the United States in 2019 but grew to account for 46% of all visits in April 2020. Changes in reimbursement and licensure policies during the COVID-19 pandemic appeared to greatly facilitate this increased use. Telehealth will continue to account for a substantial portion of care provided in the United States and globally. A better understanding of telehealth approaches and their evidence base by public health practitioners may help improve their ability to collaborate with health care organizations to improve population health. The article summarizes the Centers for Disease Control and Prevention's (CDC's) approach to understanding the evidence base for telehealth in public health practice, possible applications for telehealth in public health practice, and CDC's use of telehealth to improve population health.

Long-Term Symptoms Among Adults Tested for SARS-CoV-2 - United States, January 2020-April 2021.

Long-term symptoms often associated with COVID-19 (post-COVID conditions or long COVID) are an emerging public health concern that is not well understood. Prevalence of post-COVID conditions has been reported among persons who have had COVID-19 (range = 5%-80%), with differences possibly related to different study populations, case definitions, and data sources (1). Few studies of post-COVID conditions have comparisons with the general population of adults with negative test results for SARS-CoV-2, the virus that causes COVID-19, limiting ability to assess background symptom prevalence (1). CDC used a nonprobability-based Internet panel established by Porter Novelli Public Services* to administer a survey to a nationwide sample of U.S. adults aged ≥18 years to compare the prevalence of long-term symptoms (those lasting >4 weeks since onset) among persons who self-reported ever receiving a positive SARS-CoV-2 test result with the prevalence of similar symptoms among persons who reported always receiving a negative test result. The weighted prevalence of ever testing positive for SARS-CoV-2 was 22.2% (95% confidence interval [CI] = 20.6%-23.8%). Approximately two thirds of respondents who had received a positive test result experienced long-term symptoms often associated with SARS-CoV-2 infection. Compared with respondents who received a negative test result, those who received a positive test result reported a significantly higher prevalence of any long-term symptom (65.9% versus 42.9%), fatigue (22.5% versus 12.0%), change in sense of smell or taste (17.3% versus 1.7%), shortness of breath (15.5% versus 5.2%), cough (14.5% versus 4.9%), headache (13.8% versus 9.9%), and persistence (>4 weeks) of at least one initially occurring symptom (76.2% versus 69.6%). Compared with respondents who received a negative test result, a larger proportion of those who received a positive test result reported believing that receiving a COVID-19 vaccine made their long-term symptoms better (28.7% versus 15.7%). Efforts to address post-COVID conditions should include helping health care professionals recognize the most common post-COVID conditions and optimize care for patients with persisting symptoms, including messaging on potential benefits of COVID-19 vaccination.

Cross-sectional study of changes in physical activity behavior during the COVID-19 pandemic among US adults.

BACKGROUND: Physical activity (PA) provides numerous health benefits relevant to the COVID-19 pandemic. However, concerns exist that PA levels may have decreased during the pandemic thus exacerbating health disparities. This study aims to determine changes in and locations for PA and reasons for decreased PA during the pandemic. METHODS: Reported percentage of changes in and locations for PA and reasons for decreased PA were examined in 3829 US adults who completed the 2020 SummerStyles survey. RESULTS: Overall, 30% reported less PA, and 50% reported no change or no activity during the pandemic; percentages varied across subgroups. Adults who were non-Hispanic Black (Black) or Hispanic (vs. non-Hispanic White, (White)) reported less PA. Fewer Black adults (vs. White) reported doing most PA in their neighborhood. Concern about exposure to the virus (39%) was the most common reason adults were less active. CONCLUSIONS: In June 2020, nearly one-third of US adults reported decreased PA; 20% reported increased PA. Decreased activity was higher among Black and Hispanic compared to White adults; these two groups have experienced disproportionate COVID-19 impacts. Continued efforts are needed to ensure everyone has access to supports that allow them to participate in PA while still following guidance to prevent COVID-19 transmission.

Occupational physical activity and cardiovascular disease in the United States.

BACKGROUND: Emerging evidence, predominately from European and Asian countries, describes opposing effects of occupational physical activity (OPA) and leisure-time physical activity (LTPA) on cardiovascular health. This analysis examined cardiovascular disease (CVD) prevalence associated with OPA and LTPA. METHODS: This cross-sectional analysis of 2015 National Health Interview Survey data (n=16 974) employed logistic regression to estimate odds (OR) of self-reported CVD (coronary heart disease, heart attack, stroke or angina) with self-reported total occupational activity (TOA), occupational exertion (OE), occupational standing and walking (OSW) and LTPA. OPA was measured using two questions: 'How often does your job involve…' (1) 'repeated lifting, pushing, pulling or bending?' (OE) and (2) 'standing or walking around?' (OSW) with responses on a 5-item Likert scale (0=never, 4=always). TOA was categorised similarly after summing OE and OSW scores. LTPA was defined as 0, 1-149 or ≥150 min/week of moderate-to-vigorous activity. All models adjusted for common socioeconomic variables and additional analyses were stratified by sex, smoking status and LTPA. RESULTS: Odds for CVD were higher when 'always' performing TOA (OR 1.99 95% CI 1.12 to 3.53), OE (OR 2.15, 95% CI 1.45 to 3.19) or OSW (OR 1.84, 95% CI 1.07 to 3.17) compared with 'never'. When restricting to never-smokers, odds for CVD were higher when 'always' performing TOA (OR 3.00, 95% CI 1.38 to 6.51) and OE (OR 3.00, 95% CI 1.80 to 5.02) versus 'never'. CONCLUSION: Associations of high OPA with CVD were equally apparent across sexes, stronger in lower LTPA levels and stronger in never-smokers. While uncontrolled confounding is still possible, even after extensive adjustment, the seemingly paradoxical adverse associations with OPA and CVD should be investigated further.

Associations between the National Walkability Index and walking among US Adults - National Health Interview Survey, 2015.

The Environmental Protection Agency created the National Walkability Index (Index) to compare and analyze walkability among US communities. Index elements include design, distance to transit, and diversity of land uses. Associations between the Index and walking behavior have not been examined. This study describes associations between the Index and transportation and leisure walking among US adults. Past week self-reported participation in transportation and leisure walking among adults (n = 33,672) was obtained from the 2015 Cancer Control Supplement of the National Health Interview Survey (NHIS) and analysis completed in 2019. Index scores were linked to NHIS data based on the respondent's residence and classified into least, below average, above average, and most walkable communities. Associations between Index categories and walking were examined with regression models. Overall, the Index was associated with a higher likelihood of walking, especially for transportation. Transportation walking was more common in areas with higher walkability (21.6%-51.6%, least to most walkable). Leisure walking was also more common with greater walkability (48.4%-56.5%, least to most walkable). Transportation and leisure walking by Index categories in urban areas were similar to the overall population; however, it was not associated with walking in rural areas. US adults living in more walkable areas report more transportation and leisure walking, especially among urban areas. Consistent with elements in the Index, associations were stronger for transportation than leisure walking. Findings support the use of the Walkability Index by researchers, professionals, and other relevant stakeholders as a viable indicator of walkability.

Differences in perceived neighborhood environmental supports and barriers for walking between US adults with and without a disability.

People with disabilities are at increased risk of chronic diseases, many of which physical activity can help prevent and manage. Certain environmental features can support or hinder participation in important activities like walking, particularly for people with disabilities. The purpose of this study is to examine differences in the prevalence of perceived neighborhood environmental supports and barriers for walking, by disability status, among US adults. Participants in the 2015 National Health Interview Survey Cancer Control Supplement (N = 15,280) reported their disability status (mobility disability, non-mobility disability, or no disability) and perceptions of neighborhood environmental supports (walkable roads, sidewalks, paths, trails; sidewalks on most streets; and walkable shops; transit; movies, libraries, churches; relaxing places) and barriers (traffic, crime, animals) for walking. Adjusted models conducted in 2019 included demographic characteristics. Prevalence of most supports was lower among adults with mobility or non-mobility disabilities versus no disability. For example, 54.9% and 57.5% of adults with mobility and non-mobility disabilities respectively reported sidewalks on most streets, compared to 64.1% of adults with no disability. After adjustment, significant differences remained when comparing adults with a mobility disability versus no disability for two supports (roads, sidewalks, paths, trails; relaxing places). All perceived barriers were significantly more common among adults with any disability versus no disability, regardless of adjustment. In the United States, adults with disabilities perceive fewer neighborhood environmental supports and more barriers for walking than their counterparts. Strategies that increase supports and address barriers for walking may help promote physical activity among adults with disabilities.

Combining Data From Assessments of Leisure, Occupational, Household, and Transportation Physical Activity Among US Adults, NHANES 2011-2016.

Physical activity occurs in 4 domains (leisure, occupational, household, and transportation), but US surveillance often focuses on leisure-time only. We compared estimates of self-reported leisure-time physical activity and estimates of all-domain activity among adults in the National Health and Nutrition Examination Survey for 2011-2016. During the study period, 38.6% met the aerobic physical activity guideline in leisure-time, 58.5% in leisure-time and occupational/household activity, and 63.7% in all domains. Differences within most subgroups when using all domains were similar to differences when using leisure-time activity only, except that we observed no urban/rural differences in the multidomain assessment. Assessment of multiple domains of activity instead of leisure-time-only activity affects prevalence estimates to a greater extent than it affects subgroup differences.

Monitoring State-Level Changes in Walking, Biking, and Taking Public Transit to Work - American Community Survey, 2006 and 2017.

INTRODUCTION: Active commuting to work is one way people can be physically active and can be influenced by state-level initiatives. The American Community Survey (ACS) is a potential data source to evaluate changes in active commuting at the state level, but state-level changes have not been well documented. We examined state-level changes in estimates of walking, biking, and taking transit to work (combined and separately) among employed persons between 2006 and 2017. METHODS: Data were from the ACS, a nationally representative annual household survey from the US Census Bureau. We estimated state-level prevalence of walking, bicycling, or taking transit to work (separately and in combination) in 2006 and 2017 and tested differences by year. RESULTS: The prevalence of active commuting to work varied widely among states (2017 range: 1.7% in Alabama and Mississippi to 35.0% in New York). Changes from 2006 to 2017 also varied, with 8 states exhibiting a significant increase (Massachusetts [2.7 percentage points], New York [2.2], Hawaii [1.6], Illinois [1.3], Washington [1.3], New Jersey [1.2], Virginia [0.9], and Michigan [0.4]), and 12 exhibiting a significant decrease (South Dakota [-1.9], Idaho [-1.3], New Hampshire [-1.3], Wisconsin [-1.1], Maryland [-1.0], Nevada [-0.9], Ohio [-0.8], Mississippi [-0.6], Texas [-0.6], Florida [-0.5], Georgia [-0.4], and Indiana [-0.4]). The contributions of walking, bicycling, and taking transit also varied by state. CONCLUSION: Active commuting remains relatively rare across states. States pursuing initiatives to support active transportation may consider using ACS to monitor and evaluate changes in active commuting.

Trends in Meeting Physical Activity Guidelines Among Urban and Rural Dwelling Adults - United States, 2008-2017.

Since the release of the 2008 Physical Activity Guidelines for Americans (https://health.gov/paguidelines/2008/pdf/paguide.pdf), the age-adjusted percentage of adults meeting the combined aerobic and muscle-strengthening guidelines increased from 18.2% to 24.3% in 2017 (1). Trends in urban and rural areas, across demographic subgroups, and among subgroups within urban and rural areas have not been reported. CDC analyzed 2008-2017 National Health Interview Survey (NHIS) data to examine trends in the age-standardized prevalence of meeting physical activity guidelines among adults aged ≥18 years living in urban and rural areas. Among urban and rural residents, prevalence increased from 19.4% to 25.3% and from 13.3% to 19.6%, respectively. Nationally, all demographic subgroups and regions experienced increases over this period; increases for several groups were not consistent year-to-year. Among urban residents, the prevalence was higher during 2016-2017 than during 2008-2009 for all demographic subgroups and regions. During the same period, prevalence was higher across all rural-dwelling subgroups except Hispanics, adults with a college education, and those living in the South U.S. Census region. Urban and rural communities can implement evidence-based approaches, including improved community design, improved access to indoor and outdoor recreation facilities, social support programs, and community-wide campaigns to make physical activity the safe and easy choice for persons of all ages and abilities (2-4). Incorporating culturally appropriate strategies into local programs might help address differences across subgroups.

National-level environmental perceptions and walking among urban and rural residents: Informing surveillance of walkability.

Built environments that provide activity-friendly routes (e.g., sidewalks) to everyday destinations (e.g., shops) can increase physical activity. Surveillance of supports and destinations is important, and identifying which are associated with walking could prioritize surveillance questions. Our purpose was to identify the significant associations between supports and destinations with walking among a nationally-representative sample of urban- and rural-dwelling adults. Participants in the 2015 National Health Interview Survey, Cancer Control Supplement (n = 29,925) reported the near-home presence of walkable supports (roads, sidewalks, paths, or trails; sidewalks on most streets), destinations (shops; transit; movies, libraries, or churches; relaxing places), and past-week walking for leisure or transportation. We used stepwise logistic regression to quantify associations between supports and destinations and walking, including by urban/rural residence. We calculated the prevalence of walking across counts of reported elements by urban/rural residence. Among all participants, roads, sidewalks, paths, or trails and relaxing destinations were associated with leisure walking. Among urban residents, sidewalks on most streets and all four destination types were associated with transportation walking; among rural residents, roads, sidewalks, paths, or trails; movies, libraries, or churches; and relaxing destinations were associated with transportation walking. Walking was more common when more environmental elements were reported. To improve efficiency, communities may match surveillance priorities to behavioral priorities (i.e., leisure versus transportation walking) and environmental context (i.e., urban/rural areas). Surveillance of environments supporting leisure walking might focus on recreation-oriented spaces. Surveillance of environments supporting transportation walking might differ for urban and rural areas, and assessing destinations may be particularly important.

Racial and ethnic differences in perceived safety barriers to walking, United States National Health Interview Survey - 2015.

Barriers to safe walking may prevent people from being physically active, and previous reports have identified differences in barriers to safe walking across racial and ethnic groups. The purpose of this research was to determine the role demographic characteristics play on racial/ethnic differences in perceived barriers to safe walking and determine if racial/ethnic differences vary by urban/rural residence and Census region. Participants in the 2015 National Health Interview Survey Cancer Control Supplement (n = 31,433 adults ≥18 years) reported perceived barriers to safe walking (traffic, crime, and animals) and demographic characteristics. Urban/rural residence and Census region were based on home addresses. We calculated adjusted prevalence of barriers by race/ethnicity using logistic regression; geographic differences in barriers across racial/ethnic groups were examined via interaction terms. After adjustment for demographic characteristics, non-Hispanic blacks (blacks) and Hispanics reported crime and animals as barriers more frequently than non-Hispanic whites (whites) (crime: blacks, 22.2%; Hispanics, 16.7%; whites, 9.0%; animals: blacks, 18.0%; Hispanics, 12.4%; whites, 8.5%). Racial/ethnic differences in perceived crime as a barrier were more pronounced in the Northeast and Midwest than in the South and West. Urban-dwelling blacks (all regions) and Hispanics (Midwest and South) reported animals as barriers more frequently than whites. Racial/ethnic differences in perceived barriers to safe walking remained after adjusting for demographic characteristics and varied by geographic location. Addressing perceived crime and animals as barriers to walking could help reduce racial/ethnic differences in physical activity, and several barriers may need to be assessed to account for geographic variation.

Walking for Transportation or Leisure Among U.S. Women and Men - National Health Interview Survey, 2005-2015.

Physical activity confers considerable health benefits, but only half of U.S. adults report participating in levels of aerobic physical activity consistent with guidelines (1,2). Step It Up! The Surgeon General's Call to Action to Promote Walking and Walkable Communities identified walking as an important public health strategy to increase physical activity levels (3). A previous report showed that the self-reported prevalence of walking for transportation or leisure increased by 6 percentage points from 2005 to 2010 (4), but it is unknown whether this increase has been sustained. CDC analyzed National Health Interview Survey (NHIS) data from 2005 (26,551 respondents), 2010 (23,313), and 2015 (28,877) to evaluate trends in the age-adjusted prevalence of self-reported walking among adults aged ≥18 years. The prevalence of walking increased steadily among women, from 57.3% in 2005, to 62.5% in 2010, and to 65.1% in 2015 (significant linear trend). Among men, a significant linear increase in reported walking was observed, from 54.3% in 2005, to 61.8% in 2010, and to 62.8% in 2015, although the increase stalled between 2010 and 2015 (significant linear and quadratic trends). Community design policies and practices that encourage pedestrian activity and programs tailored to the needs of specific population subgroups remain important strategies for promoting walking (3).

Association Between User-Generated Commuting Data and Population-Representative Active Commuting Surveillance Data - Four Cities, 2014-2015.

Creating environments that support all types of physical activity, including active transportation, is a public health priority (1). Public health surveillance that identifies the locations where community members walk and bicycle (i.e., engage in active transportation) can inform such efforts. Traditional population-representative active transportation surveillance incurs a considerable time lag between data collection and dissemination, and often lacks geographic specificity (2). Conversely, user-generated active transportation data from Global Positioning System (GPS)-based activity tracking devices and mobile applications can provide near real-time information, but might be subject to self-selection bias among users. CDC analyzed the association between GPS-based commuting data from a company that allows tracking of activity with a mobile application (Strava, Inc., San Francisco, California) and population-representative commuting data from the U.S. Census Bureau's American Community Survey (ACS) (3) for four U.S. cities. The level of analysis was the Census block group. The number of GPS-tracked commuters in Strava was associated with the number of ACS active commuters (Spearman's rho = 0.60), suggesting block groups were ranked similarly based on these distinct but related measurements. The correlation was higher in high population density areas. User-generated active transportation data might complement traditional surveillance systems by providing near real-time, location-specific information on where active transportation occurs.

Ecological Analysis of Parking Prices and Active Commuting in US Cities, 2009.

We conducted an ecological study to determine whether parking prices are associated with active commuting across US cities. We obtained parking prices for 107 US cities from the Drexel University Central Business District Public Parking Survey, obtained city prevalence of walking and bicycling to work from the American Community Survey, and used weighted least squares linear regression to explore associations between parking prices and active commuting. After adjusting for several covariates, walking to work was 3.1% higher for every additional dollar charged for off-street daily parking, but only among more densely populated cities, and no such association was detected for bicycling to work. These preliminary results hint at the potential for parking policies to influence commuting mode choice, a link that city planners and public health officials could consider when evaluating parking policies and active transportation behaviors.