Harmonization of data for pooled analysis relies on the principle of inferential equivalence between variables from different sources. Ideally, this is achieved using models of the direct relationship with gold standard criterion measures, but the necessary validation study data are often unavailable. This study examines an alternative method of network harmonization using indirect models. Starting methods were self-report or accelerometry, from which we derived indirect models of relationships with doubly labelled water (DLW)-based physical activity energy expenditure (PAEE) using sets of two bridge equations via one of three intermediate measures. Coefficients and performance of indirect models were compared to corresponding direct models (linear regression of DLW-based PAEE on starting methods). Indirect model beta coefficients were attenuated compared to direct model betas (10%–63%), narrowing the range of PAEE values; attenuation was greater when bridge equations were weak. Directly and indirectly harmonized models had similar error variance but most indirectly derived values were biased at group-level. Correlations with DLW-based PAEE were identical after harmonization using continuous linear but not categorical models. Wrist acceleration harmonized to DLW-based PAEE via combined accelerometry and heart rate sensing had the lowest error variance (24.5%) and non-significant mean bias 0.9 (95%CI: −1.6; 3.4) kJ·day−1·kg−1. Associations between PAEE and BMI were similar for directly and indirectly harmonized values, but most fell outside the confidence interval of the criterion PAEE-to-BMI association. Indirect models can be used for harmonization. Performance depends on the measurement properties of original data, variance explained by available bridge equations, and similarity of population characteristics.
Matthew Pearce, Tom R.P. Bishop, Stephen Sharp, Kate Westgate, Michelle Venables, Nicholas J. Wareham, and Søren Brage
Melanna F. Cox, Greg J. Petrucci Jr., Robert T. Marcotte, Brittany R. Masteller, John Staudenmayer, Patty S. Freedson, and John R. Sirard
Purpose: Develop a direct observation (DO) system to serve as a criterion measure for the calibration of models applied to free-living (FL) accelerometer data. Methods: Ten participants (19.4 ± 0.8 years) were video-recorded during four, one-hour FL sessions in different settings: 1) school, 2) home, 3) community, and 4) physical activity. For each setting, 10-minute clips from three randomly selected sessions were extracted and coded by one expert coder and up to 20 trained coders using the Observer XT software (Noldus, Wageningen, the Netherlands). The coder defines each whole-body movement which was further described with three modifiers: 1) locomotion, 2) activity type, and 3) MET value (used to categorize intensity level). Percent agreement was calculated for intra- and inter-rater reliability. For intra-rater reliability, the criterion coder coded all 12 clips twice, separated by at least one week between coding sessions. For inter-rater reliability, coded clips by trained coders were compared to the expert coder. Intraclass correlations (ICCs) were calculated to assess the agreement of intensity category for intra- and inter-rater comparisons described above. Results: For intra-rater reliability, mean percent agreement ranged from 91.9 ± 3.9% to 100.0 ± 0.0% across all variables in all settings. For inter-rater reliability, mean percent agreement ranged from 88.2 ± 3.5% to 100.0 ± 0.0% across all variables in all settings. ICCs for intensity category ranged from 0.74–1.00 and 0.81–1.00 for intra- and inter-rater comparisons, respectively. Conclusion: The DO system is reliable and feasible to serve as a criterion measure of FL physical activity in young adults to calibrate accelerometers, subsequently improving interpretation of surveillance and intervention research.
Katrina L. Piercy, Frances Bevington, Alison Vaux-Bjerke, Sandra Williams Hilfiker, Sean Arayasirikul, and Elizabeth Y. Barnett
Background: The Office of Disease Prevention and Health Promotion completed research to understand factors that could encourage Americans to follow the Physical Activity Guidelines for Americans, second edition, released in 2018. This study describes survey research assessing demographic characteristics that might be related to knowledge and awareness of the guidelines. Methods: An online survey of 2050 adult physical activity contemplators assessed knowledge of physical activity, awareness of the guidelines, and knowledge of dosage recommendations. Univariate and bivariate analyses were performed, and demographic differences in knowledge and awareness were analyzed using Pearson chi-square tests and Fisher exact tests. Results: Respondents had medium to high knowledge of physical activity, although knowledge varied significantly by socioeconomic factors. Knowledge of dosage recommendations was very low, with 2% and 3% of respondents correctly identifying recommended moderate- and vigorous-intensity doses, respectively. Only 22% were aware of the guidelines; awareness was greater among those with a higher education or income and those without a disability. Conclusions: These findings guided the development of the Office of Disease Prevention and Health Promotion’s Move Your Way campaign and reinforced the need to raise awareness of the guidelines and promote behavior change among physical activity contemplators—particularly those from lower socioeconomic groups.
Frances Bevington, Katrina L. Piercy, Kate Olscamp, Sandra W. Hilfiker, Dena G. Fisher, and Elizabeth Y. Barnett
Background: The Move Your Way campaign, developed by the Office of Disease Prevention and Health Promotion, aims to improve Americans’ adherence to the Physical Activity Guidelines for Americans. This article describes the research that informed the campaign’s products, messaging, and strategy. Methods: A mixed-methods approach was used to understand participants’ preferences for physical activity messages and information seeking. Two rounds (round 1 [n = 95] and round 2 [n = 73]) of focus groups and an online survey (n = 2050) were conducted with adult physical activity contemplators. A third round (n = 84) of focus groups was conducted with children, teens, and parents of young children. Results: Adults, parents, teens, and children preferred messages that reflected diverse examples of activities; most participants disliked “one-size-fits-all” recommendations. Adults and parents preferred messages that emphasized specific health benefits over generic messages about overall health. Although some participants preferred getting physical activity information from digital search tools and social media platforms, many preferred getting this information from family members and friends. Conclusion: The Office of Disease Prevention and Health Promotion translated these findings into 3 themes used for Move Your Way implementation: (1) leverage social and community connections, (2) emphasize representation through inclusion and diversity, and (3) customize physical activity recommendations to make them more achievable.
Rachel G. Curtis, Dorothea Dumuid, Timothy Olds, Ronald Plotnikoff, Corneel Vandelanotte, Jillian Ryan, Sarah Edney, and Carol Maher
Background: Substantial evidence links activity domains with health and well-being; however, research has typically examined time-use behaviors independently, rather than considering daily activity as a 24-hour time-use composition. This study used compositional data analysis to estimate the difference in physical and mental well-being associated with reallocating time between behaviors. Methods: Participants (n = 430; 74% female; 41  y) wore an accelerometer for 7 days and reported their body mass index; health-related quality of life (QoL); and symptoms of depression, anxiety, and stress. Regression models determined whether time-use composition, comprising sleep, sedentary behavior, light physical activity (LPA), and moderate to vigorous physical activity (MVPA), was associated with well-being. Compositional isotemporal substitution models estimated the difference in well-being associated with reallocating time between behaviors. Results: Time-use composition was associated with body mass index and physical health-related QoL. Reallocating time to MVPA from sleep, sedentary behavior, and LPA showed favorable associations with body mass index and physical health-related QoL, whereas reallocations from MVPA to other behaviors showed unfavorable associations. Reallocations from LPA to sedentary behavior were associated with better physical health–related QoL and vice versa. Conclusion: Results reinforce the importance of MVPA for physical health but do not suggest that replacing sedentary behavior with LPA is beneficial for health and well-being.
E. Kipling Webster, Leah E. Robinson, and Danielle D. Wadsworth
Background: Activity breaks are an established way physical activity may be incorporated into the preschool day. The purpose of this study was to examine what factors influenced moderate to vigorous physical activity (MVPA) during a teacher-implemented classroom-based activity break (CBAB) in a Head Start population. Methods: Ten-minute CBAB was conducted over 2 days in a quasi-experimental design; 99 preschoolers (mean age 3.80 [0.65] y; 49.5% male) from a convenience sample participated. Accelerometers measured MVPA, fundamental motor skill competency was assessed using the Test of Gross Motor Development—second edition, and weight classification status used body mass index percentiles. Results: A significant, moderate regression was found (r = .328, P = .001) between fundamental motor skill and MVPA. There was no significant correlation between body mass index percentile and MVPA during the CBAB. In addition, the locomotor subscale was the best predictor for MVPA for children during the CBAB (r = .32, β = 0.82, P < .001). Conclusions: CBAB equally elicited MVPA for normal and overweight preschoolers. Fundamental motor skill competency was associated with MVPA during the CBAB; in particular, locomotor skills were the best predictor for physical activity. Structured activity opportunities that focus on locomotor skills may be a useful integration to prompt more MVPA in a preschool-age population.
Paul J. Collings, Diane Farrar, Joanna Gibson, Jane West, Sally E. Barber, and John Wright
Background: Physical activity performed while pregnant is beneficially associated with maternal cardiovascular health. It is unknown if benefits extend to neonatal cardiovascular health. This study investigated associations of maternal physical activity with neonatal cord blood lipid and lipoprotein concentrations. Methods: Cord blood lipids were measured at birth in a pseudorandomly selected subgroup of Born in Bradford birth cohort participants (N = 1634). Pregnant women were grouped into 4 activity categories (inactive/somewhat active/moderately active/active) based on their self-reported physical activity at 26- to 28-weeks gestation. Regression was used to calculate adjusted mean differences in neonatal cord blood lipid concentrations among the 4 groups of physical activity. Results: Maternal physical activity was associated with higher neonatal cord blood high-density lipoprotein cholesterol. Cord blood high-density lipoprotein cholesterol was higher in neonates of women who were somewhat and moderately active compared with neonates of women who were inactive. There were no associations of pregnancy physical activity with triglycerides, low-density lipoprotein, very low-density lipoprotein cholesterol, or adiponectin levels. Conclusions: Maternal physical activity is favorably associated with neonatal cord blood high-density lipoprotein cholesterol levels. This novel beneficial finding highlights the potential for physical activity in pregnancy to aid the early prevention of cardiovascular disease.
Chia-Yuan Yu and Biyuan Wang
Background: This study explored the percentage change of walking to/from public transit to work from 2009 to 2017 in general and for specific sociodemographic characteristics. Furthermore, this study also examined the sociodemographic characteristics of those who walked to/from transit to work and those who walked 30 minutes or more per day to/from transit to work and compared the difference between 2009 and 2017. Methods: 2009 and 2017 National Household Travel Survey were used. This study used weighted logistic regressions to explore the sociodemographic characteristics of those who walked to/from transit to work and those who walked 30 minutes or more per day to/from transit to work in both 2009 and 2017. Results: The percentage of trips achieving the recommended level of physical activity (30 min or more per day) by walking to/from transit work solely has a slightly increase from 9 in 2009 to 9.5 in 2017. However, the weighted percentages of walking to/from transit to work decreased for low-education, low-income, and minority populations. High population density areas were related to more transit-related walking trips to work in both 2009 and 2017. Conclusions: Policymakers in terms of transit location and service should consider low-education, low-income, and minority populations to address potential equity issues.