Validation of Total Water Intake from the Automated Self-Administered 24-h Recall, 4-d Food Records, and a Food Frequency Questionnaire Using Doubly Labeled Water

BACKGROUND

Although prior evidence indicates that water intake is important for health, the ability to accurately measure community-dwelling intake is limited. Only a few studies have evaluated self-reported water intake against an objective recovery biomarker.

OBJECTIVES

The aim was to compare preformed water intakes (all sources including food) by multiple Automated Self-Administered 24-h recalls (ASA24s), food frequency questionnaires (FFQs), and 4-d food records (4DFRs) against a recovery biomarker, doubly labeled water (DLW), to assess measurement error.

METHODS

Over 1 y, 1082 women and men (50%), aged 50 to 74 y, were asked to complete 6 ASA24s, 2 FFQs, 2 unweighted 4DFRs, and an administration of DLW (n = 686). Geometric means of water intake by self-report tools were compared with DLW. Attenuation factors and correlation coefficients between self-reported and the recovery biomarker (DLW) were estimated.

RESULTS

Mean water intakes by DLW were 2777 mL/d (interquartile range, 2350 to 3331) in women and 3243 mL/d (interquartile range, 2720 to 3838) in men. Compared with DLW, water intake was underestimated by 18% to 31% on ASA24s and 43% to 44% on 4DFRs. Estimated geometric means from FFQs differed from DLW by -1% to +13%. For a single ASA24, FFQ, and 4DFR, attenuation factors were 0.28, 0.27, and 0.32 and correlation coefficients were 0.46, 0.48, and 0.49, respectively. Repeated use of 6 ASA24s, 2 FFQs, and 2 4DFRs improved attenuation factors to 0.43, 0.32, and 0.39 and correlation coefficients to 0.58, 0.53, and 0.54, respectively.

CONCLUSIONS

FFQs may better estimate population means for usual water intake compared with ASA24 and 4DFR. Similar attenuation factors and correlation coefficients across all self-report tools indicate that researchers have 3 feasible options if the goal is understanding intake-disease relationships. The findings are useful for planning future nutrition studies that set policy priorities for populations and to understand the health impact of water. This trial was registered at clinicaltrials.gov as NCT03268577.

Using a smartphone application to capture daily work activities: a longitudinal pilot study in a farming population

OBJECTIVES

Smartphones are increasingly used to collect real-time information on time-varying exposures. We developed and deployed an application (app) to evaluate the feasibility of using smartphones to collect real-time information on intermittent agricultural activities and to characterize agricultural task variability in a longitudinal study of farmers.

METHODS

We recruited 19 male farmers, aged 50-60 years, to report their farming activities on 24 randomly selected days over 6 months using the Life in a Day app. Eligibility criteria include personal use of an iOS or Android smartphone and >4 h of farming activities at least two days per week. We developed a study-specific database of 350 farming tasks that were provided in the app; 152 were linked to questions that were asked when the activity ended. We report eligibility, study compliance, number of activities, duration of activities by day and task, and responses to the follow-up questions.

RESULTS

Of the 143 farmers we reached out to for this study, 16 were not reached by phone or refused to answer eligibility questions, 69 were ineligible (limited smartphone use and/or farming time), 58 met study criteria, and 19 agreed to participate. Refusals were mostly related to uneasiness with the app and/or time commitment (32 of 39). Participation declined gradually over time, with 11 farmers reporting activities through the 24-week study period. We obtained data on 279 days (median 554 min/day; median 18 days per farmer) and 1,321 activities (median 61 min/activity; median 3 activities per day per farmer). The activities were predominantly related to animals (36%), transportation (12%), and equipment (10%). Planting crops and yard work had the longest median durations; short-duration tasks included fueling trucks, collecting/storing eggs, and tree work. Time period-specific variability was observed; for example, crop-related activities were reported for an average of 204 min/day during planting but only 28 min/day during pre-planting and 110 min/day during the growing period. We obtained additional information for 485 (37%) activities; the most frequently asked questions were related to "feed animals" (231 activities) and "operate fuel-powered vehicle (transportation)" (120 activities).

CONCLUSIONS

Our study demonstrated feasibility and good compliance in collecting longitudinal activity data over 6 months using smartphones in a relatively homogeneous population of farmers. We captured most of the farming day and observed substantial heterogeneity in activities, highlighting the need for individual activity data when characterizing exposure in farmers. We also identified several areas for improvement. In addition, future evaluations should include more diverse populations.

Measurement Error Affecting Web- and Paper-Based Dietary Assessment Instruments: Insights From the Multi-Cohort Eating and Activity Study for Understanding Reporting Error

Few biomarker-based validation studies have examined error in online self-report dietary assessment instruments, and food records (FRs) have been considered less than food frequency questionnaires (FFQs) and 24-hour recalls (24HRs). We investigated measurement error in online and paper-based FFQs, online 24HRs, and paper-based FRs in 3 samples drawn primarily from 3 cohorts, comprising 1,393 women and 1,455 men aged 45-86 years. Data collection occurred from January 2011 to October 2013. Attenuation factors and correlation coefficients between reported and true usual intake for energy, protein, sodium, potassium, and respective densities were estimated using recovery biomarkers. Across studies, average attenuation factors for energy were 0.07, 0.07, and 0.19 for a single FFQ, 24HR, and FR, respectively. Correlation coefficients for energy were 0.24, 0.23, and 0.40, respectively. Excluding energy, the average attenuation factors across nutrients and studies were 0.22 for a single FFQ, 0.22 for a single 24HR, and 0.51 for a single FR. Corresponding correlation coefficients were 0.31, 0.34, and 0.53, respectively. For densities (nutrient expressed relative to energy), the average attenuation factors across studies were 0.37, 0.17, and 0.50, respectively. The findings support prior research suggesting different instruments have unique strengths that should be leveraged in epidemiologic research.

Examining the association between meal context and diet quality: an observational study of meal context in older adults

Background

Though a healthy diet is widely associated with reduced risks for chronic disease and mortality, older adults in the U.S. on average do not meet dietary recommendations. Given that few studies have examined the association between meal context on older adult diet quality, the aims of this study were (1) to compare the dietary quality of foods consumed in different meal contexts, as measured by the Healthy Eating Index 2015 (HEI-2015): meal location, the presence of others, and the use of electronic screens; and (2) to examine which components of the HEI-2015 drove differences in HEI-2015 total scores by meal context.

Methods

Interactive Diet and Activity Tracking in AARP study participants (50–74 years) completed the Automated Self-Administered 24-h Dietary Assessment tool (ASA24, version 2011) that included foods and beverages consumed and three meal contexts: “at home” versus “away from home,” “alone” versus “with company,” and “with screen time” versus “without screen time.” A population ratio approach was used to estimate HEI-2015 total and component scores for all food items consumed by meal context. Mean HEI-2015 scores (range: 0–100) for the three meal context variables were compared using t-tests. Where there were significant differences in total scores, additional t-tests were used to explore which HEI-2015 components were the primary drivers. All tests were stratified by sex and adjusted for multiple comparisons.

Results

HEI-2015 scores were lower for meals consumed away vs. at home (mean difference (SE), males: − 8.23 (1.02); females: − 7.29 (0.93); both p < 0.0001) and for meals eaten with vs. without company (mean difference (SE), males: − 6.61 (1.06); females: − 7.34 (1.18); both p < 0.0001). There was no difference comparing with vs. without screen time. When HEI-2015 component scores were examined, fewer total fruits, whole grains, and dairy were consumed away from home or with company; more total vegetables and greens and beans, and less added sugars were consumed with company.

Conclusions

Our findings suggest an association between the behavior cues of meal location and companions and dietary choices among older adults. Future studies can explore the individual and interactive effects of meal context on diet quality and subsequent health outcomes.

Associations of Sedentary Time with Energy Expenditure and Anthropometric Measures

PURPOSE

To investigate associations between accelerometer-determined sedentary time (ST) in prolonged (≥30 min) and nonprolonged (<30 min) bouts with physical activity energy expenditure (PAEE) from doubly labeled water. Additionally, associations between ST and body mass index (BMI) and waist circumference were examined.

METHODS

Data from 736 women and 655 men age 43 to 82 yr were analyzed. Participants wore the Actigraph GT3X for 7 d on two occasions approximately 6 months apart, and the average of the measurements was used. Physical activity energy expenditure was estimated by subtracting resting metabolic rate and the thermic effect of food from doubly labeled water estimates of total daily energy expenditure. Cross-sectional associations were analyzed using isotemporal substitution modeling.

RESULTS

Reallocation of prolonged ST to nonprolonged was not associated with increased PAEE and only significantly associated with lower BMI (β = -0.57 kg·m; 95% confidence interval, -0.94 to -0.20) and waist circumference (β = -1.61 cm; 95% confidence interval, -2.61 to -0.60) in men. Replacing either type of ST with light or moderate-to-vigorous physical activity was significantly associated with higher PAEE, and lower BMI and waist circumference in both women and men.

CONCLUSIONS

Limiting time spent sedentary as well as decreasing ST accumulated in prolonged bouts may have beneficial effects on BMI and waist circumference. Replacing any type of ST with activities of light or higher intensity may also have a substantial impact on PAEE.

Physical Activity Assessment with the ActiGraph GT3X and Doubly Labeled Water

PURPOSE

To compare the degree to which four accelerometer metrics-total activity counts per day (TAC per day), steps per day (steps per day), physical activity energy expenditure (PAEE) (kcal·kg·d), and moderate- to vigorous-intensity physical activity (MVPA) (min·d)-were correlated with PAEE measured by doubly labeled water (DLW). Additionally, accelerometer metrics based on vertical axis counts and triaxial counts were compared.

METHODS

This analysis included 684 women and 611 men age 43 to 83 yr. Participants wore the Actigraph GT3X on the hip for 7 d twice during the study and the average of the two measurements was used. Each participant also completed one DLW measurement, with a subset having a repeat. PAEE was estimated by subtracting resting metabolic rate and the thermic effect of food from total daily energy expenditure estimated by DLW. Partial Spearman correlations were used to estimate associations between PAEE and each accelerometer metric.

RESULTS

Correlations between the accelerometer metrics and DLW-determined PAEE were higher for triaxial counts than vertical axis counts. After adjusting for weight, age, accelerometer wear time, and fat free mass, the correlation between TAC per day based on triaxial counts and DLW-determined PAEE was 0.44 in women and 0.41 in men. Correlations for steps per day and accelerometer-estimated PAEE with DLW-determined PAEE were similar. After adjustment for within-person variation in DLW-determined PAEE, the correlations for TAC per day increased to 0.61 and 0.49, respectively. Correlations between MVPA and DLW-determined PAEE were lower, particularly for modified bouts of ≥10 min.

CONCLUSIONS

Accelerometer measures that represent total activity volume, including TAC per day, steps per day, and PAEE, were more highly correlated with DLW-determined PAEE than MVPA using traditional thresholds and should be considered by researchers seeking to reduce accelerometer data to a single metric.

Reporting accelerometer methods in physical activity intervention studies: a systematic review and recommendations for authors

OBJECTIVE

This systematic review assessed the completeness of accelerometer reporting in physical activity (PA) intervention studies and assessed factors related to accelerometer reporting.

DESIGN

The PubMed database was used to identify manuscripts for inclusion. Included studies were PA interventions that used accelerometers, were written in English and were conducted between 1 January 1998 and 31 July 2014. 195 manuscripts from PA interventions that used accelerometers to measure PA were included. Manuscript completeness was scored using 12 questions focused on 3 accelerometer reporting areas: accelerometer information, data processing and interpretation and protocol non-compliance. Variables, including publication year, journal focus and impact factor, and population studied were evaluated to assess trends in reporting completeness.

RESULTS

The number of manuscripts using accelerometers to assess PA in interventions increased from 1 in 2002 to 29 in the first 7 months of 2014. Accelerometer reporting completeness correlated weakly with publication year (r=0.24, p<0.001). Correlations were greater when we assessed improvements over time in reporting data processing in manuscripts published in PA-focused journals (r=0.43, p=0.002) compared to manuscripts published in non-PA-focused journals (r=0.19, p=0.021). Only 7 of 195 (4%) manuscripts reported all components of accelerometer use, and only 132 (68%) reported more than half of the components.

CONCLUSIONS

Accelerometer reporting of PA in intervention studies has been poor and improved only minimally over time. We provide recommendations to improve accelerometer reporting and include a template to standardise reports.

NCI Funding Trends and Priorities in Physical Activity and Energy Balance Research Among Cancer Survivors

There is considerable evidence that a healthy lifestyle consisting of physical activity, healthy diet, and weight control is associated with reduced risk of morbidity and mortality after cancer. However, these behavioral interventions are not widely adopted in practice or community settings. Integrating heath behavior change interventions into standard survivorship care for the growing number of cancer survivors requires an understanding of the current state of the science and a coordinated scientific agenda for the future with focused attention in several priority areas. To facilitate this goal, this paper presents trends over the past decade of the National Cancer Institute (NCI) research portfolio, fiscal year 2004 to 2014, by funding mechanism, research focus, research design and methodology, primary study exposures and outcomes, and study team expertise and composition. These data inform a prioritized research agenda for the next decade focused on demonstrating value and feasibility and creating desire for health behavior change interventions at multiple levels including the survivor, clinician, and healthcare payer to facilitate the development and implementation of appropriately targeted, adaptive, effective, and sustainable programs for all survivors.

Ability of thigh-worn ActiGraph and activPAL monitors to classify posture and motion

PURPOSE

This study compared sitting, standing, and stepping classifications from thigh-worn ActiGraph and activPAL monitors under laboratory and free-living conditions.

METHODS

Adults wore both monitors on the right thigh while performing activities (six sitting, two standing, nine stepping, and one cycling) and writing on a whiteboard with intermittent stepping under laboratory conditions (n = 21) and under free-living conditions for 3 d (n = 18). Percent time correctly classified was calculated under laboratory conditions. Between-monitor agreement and weighted κ were calculated under free-living conditions.

RESULTS

In the laboratory, both monitors correctly classified 100% of standing time and >95% of the time spent in four of six sitting postures. Both monitors demonstrated misclassification of laboratory stool sitting time (ActiGraph 14% vs. activPAL 95%). ActivPAL misclassified 14% of the time spent sitting with legs outstretched; ActiGraph was 100% accurate. Monitors were >95% accurate for stepping, although ActiGraph was less so for descending stairs (86%), ascending stairs (92%), and running at 2.91 m·s(-1) (93%). Monitors classified whiteboard writing differently (ActiGraph 83% standing/15% stepping vs. activPAL 98% standing/2% stepping). ActivPAL classified 93% of cycling time as stepping, whereas ActiGraph classified <1% of cycling time as stepping. During free-living wear, monitors had substantial agreement (86% observed; weighted κ = 0.77). Monitors classified similar amounts of time as sitting (ActiGraph 64% vs. activPAL 62%). There were differences in time recorded as standing (ActiGraph 21% vs. activPAL 27%) and stepping (ActiGraph 15% vs. activPAL 11%).

CONCLUSIONS

Differences in data processing algorithms may have resulted in the observed disagreement in posture and activity classification between thigh-worn ActiGraph and activPAL. Despite between-monitor agreement in classifying sitting time under free-living conditions, ActiGraph appears to be more sensitive to free-living upright walking motions than activPAL.

Validation of a previous-day recall measure of active and sedentary behaviors

PURPOSE

A previous-day recall (PDR) may be a less error-prone alternative to traditional questionnaire-based estimates of physical activity and sedentary behavior (e.g., past year), but the validity of the method is not established. We evaluated the validity of an interviewer administered PDR in adolescents (12-17 yr) and adults (18-71 yr).

METHODS

In a 7-d study, participants completed three PDR, wore two activity monitors, and completed measures of social desirability and body mass index. PDR measures of active and sedentary time was contrasted against an accelerometer (ActiGraph) by comparing both to a valid reference measure (activPAL) using measurement error modeling and traditional validation approaches.

RESULTS

Age- and sex-specific mixed models comparing PDR to activPAL indicated the following: 1) there was a strong linear relationship between measures for sedentary (regression slope, β1 = 0.80-1.13) and active time (β1 = 0.64-1.09), 2) person-specific bias was lower than random error, and 3) correlations were high (sedentary: r = 0.60-0.81; active: r = 0.52-0.80). Reporting errors were not associated with body mass index or social desirability. Models comparing ActiGraph to activPAL indicated the following: 1) there was a weaker linear relationship between measures for sedentary (β1 = 0.63-0.73) and active time (β1 = 0.61-0.72), (2) person-specific bias was slightly larger than random error, and (3) correlations were high (sedentary: r = 0.68-0.77; active: r = 0.57-0.79).

CONCLUSIONS

Correlations between the PDR and the activPAL were high, systematic reporting errors were low, and the validity of the PDR was comparable with the ActiGraph. PDR may have value in studies of physical activity and health, particularly those interested in measuring the specific type, location, and purpose of activity-related behaviors.

Perceived neighborhood environment and physical activity in 11 countries: do associations differ by country?

BACKGROUND

Increasing empirical evidence supports associations between neighborhood environments and physical activity. However, since most studies were conducted in a single country, particularly western countries, the generalizability of associations in an international setting is not well understood. The current study examined whether associations between perceived attributes of neighborhood environments and physical activity differed by country.

METHODS

Population representative samples from 11 countries on five continents were surveyed using comparable methodologies and measurement instruments. Neighborhood environment × country interactions were tested in logistic regression models with meeting physical activity recommendations as the outcome, adjusted for demographic characteristics. Country-specific associations were reported.

RESULTS

Significant neighborhood environment attribute × country interactions implied some differences across countries in the association of each neighborhood attribute with meeting physical activity recommendations. Across the 11 countries, land-use mix and sidewalks had the most consistent associations with physical activity. Access to public transit, bicycle facilities, and low-cost recreation facilities had some associations with physical activity, but with less consistency across countries. There was little evidence supporting the associations of residential density and crime-related safety with physical activity in most countries.

CONCLUSION

There is evidence of generalizability for the associations of land use mix, and presence of sidewalks with physical activity. Associations of other neighborhood characteristics with physical activity tended to differ by country. Future studies should include objective measures of neighborhood environments, compare psychometric properties of reports across countries, and use better specified models to further understand the similarities and differences in associations across countries.

Patterns of neighborhood environment attributes related to physical activity across 11 countries: a latent class analysis

BACKGROUND

Neighborhood environment studies of physical activity (PA) have been mainly single-country focused. The International Prevalence Study (IPS) presented a rare opportunity to examine neighborhood features across countries. The purpose of this analysis was to: 1) detect international neighborhood typologies based on participants' response patterns to an environment survey and 2) to estimate associations between neighborhood environment patterns and PA.

METHODS

A Latent Class Analysis (LCA) was conducted on pooled IPS adults (N=11,541) aged 18 to 64 years old (mean=37.5±12.8 yrs; 55.6% women) from 11 countries including Belgium, Brazil, Canada, Colombia, Hong Kong, Japan, Lithuania, New Zealand, Norway, Sweden, and the U.S. This subset used the Physical Activity Neighborhood Environment Survey (PANES) that briefly assessed 7 attributes within 10-15 minutes walk of participants' residences, including residential density, access to shops/services, recreational facilities, public transit facilities, presence of sidewalks and bike paths, and personal safety. LCA derived meaningful subgroups from participants' response patterns to PANES items, and participants were assigned to neighborhood types. The validated short-form International Physical Activity Questionnaire (IPAQ) measured likelihood of meeting the 150 minutes/week PA guideline. To validate derived classes, meeting the guideline either by walking or total PA was regressed on neighborhood types using a weighted generalized linear regression model, adjusting for gender, age and country.

RESULTS

A 5-subgroup solution fitted the dataset and was interpretable. Neighborhood types were labeled, "Overall Activity Supportive (52% of sample)", "High Walkable and Unsafe with Few Recreation Facilities (16%)", "Safe with Active Transport Facilities (12%)", "Transit and Shops Dense with Few Amenities (15%)", and "Safe but Activity Unsupportive (5%)". Country representation differed by type (e.g., U.S. disproportionally represented "Safe but Activity Unsupportive"). Compared to the Safe but Activity Unsupportive, two types showed greater odds of meeting PA guideline for walking outcome (High Walkable and Unsafe with Few Recreation Facilities, OR=2.26 (95% CI 1.18-4.31); Overall Activity Supportive, OR=1.90 (95% CI 1.13-3.21). Significant but smaller odds ratios were also found for total PA.

CONCLUSIONS

Meaningful neighborhood patterns generalized across countries and explained practical differences in PA. These observational results support WHO/UN recommendations for programs and policies targeted to improve features of the neighborhood environment for PA.

The association between television watching time and all-cause mortality after breast cancer

PURPOSE

Sedentary time is a rapidly emerging independent risk factor for mortality in the general population, but its prognostic effect among cancer survivors is unknown. In a multiethnic, prospective cohort of breast cancer survivors, we hypothesized that television watching time would be independently associated with an increased risk of death from any cause.

METHODS

The Health, Eating, Activity, and Lifestyle Study cohort included 687 women diagnosed with local or regional breast cancer. On average 30 (±4) months postdiagnosis, women completed self-report assessments on time spent sitting watching television/videos in a typical day in the previous year. Multivariate Cox proportional hazards models were used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for death from any cause (n = 89) during the 7 years of follow-up.

RESULTS

Television time (top tertile vs. bottom tertile) was positively related to risk of death (HR, 1.94; 95 % CI, 1.02, 3.66, p trend = 0.024), but the association was attenuated and not statistically significant after adjustment for aerobic moderate-vigorous intensity physical activity (HR, 1.70; 95 % CI, 0.89, 3.22, p trend = 0.14) and all covariates (HR, 1.39; 95 % CI, 0.69, 2.82, p trend = 0.48).

CONCLUSION

In this first published investigation on this topic, we did not observe a statistically significant multivariate-adjusted association between television watching time and risk of death among women diagnosed with breast cancer.

IMPLICATIONS FOR CANCER SURVIVORS

These results begin an evidence base on this topic that can be built upon to inform lifestyle recommendations for this expanding, aging population.

Best practices for using physical activity monitors in population-based research

The use of physical activity monitors in population-based research has increased dramatically in the past decade. In this report, we review the major purpose for using physical activity monitors in different types of population-based studies (i.e., surveillance, intervention, association studies) and discuss the strengths and weaknesses for the various behavioral outcomes derived from monitors for each study type. We also update and extend previous recommendations for use of these instruments in large-scale studies, particularly with respect to selecting monitor systems in the context of technological advances that have occurred in recent years. The current state of the science with respect to optimal measurement schedules for use of physical activity monitors is also discussed. A checklist and flowchart are provided so that investigators have more guidance when reporting key elements of monitor use in their studies.

Assessment of physical activity using wearable monitors: recommendations for monitor calibration and use in the field

This article provides recommendations for the use of wearable monitors for assessing physical activity. We have provided recommendations for measurement researchers, end users, and developers of activity monitors. We discuss new horizons and future directions in the field of objective measurement of physical activity and present challenges that remain for the future. These recommendations are based on the proceedings from the workshop "Objective Measurement of Physical Activity: Best Practices and Future Direction," held on July 20-21, 2009, and also on data and information presented since the workshop.

Improving self-reports of active and sedentary behaviors in large epidemiologic studies

Questionnaires that assess active and sedentary behaviors in large-scale epidemiologic studies are known to contain substantial errors. We present three options for improving measures of physical activity behaviors in large-scale epidemiologic studies, discuss the problems and prospects for each of these options, and highlight a new direction for measuring these behaviors in such studies.

Amount of time spent in sedentary behaviors and cause-specific mortality in US adults

BACKGROUND

Sedentary behaviors predominate modern life, yet we do not fully understand the adverse effects of these behaviors on mortality after considering the benefits of moderate-vigorous physical activity (MVPA).

OBJECTIVE

We tested the hypotheses that higher amounts of overall sitting time and television viewing are positively associated with mortality and described the independent and combined effects of these sedentary behaviors and MVPA on mortality.

DESIGN

In the NIH-AARP Diet and Health Study, we examined 240,819 adults (aged 50-71 y) who did not report any cancer, cardiovascular disease, or respiratory disease at baseline. Mortality was ascertained over 8.5 y.

RESULTS

Sedentary behaviors were positively associated with mortality after adjustment for age, sex, education, smoking, diet, race, and MVPA. Participants who reported the most television viewing (≥7 h compared with <1 h/d) were at greater risk of all-cause (HR: 1.61; 95% CI: 1.47, 1.76), cardiovascular (HR: 1.85; 95% CI: 1.56, 2.20), and cancer (HR: 1.22; 95% CI: 1.06, 1.40) mortality after adjustment for MVPA. Overall sitting was associated with all-cause mortality. Even among adults reporting high levels of MVPA (>7 h/wk), high amounts of television viewing (≥7 h/d) remained associated with increased risk of all-cause (HR: 1.47; 95% CI: 1.20, 1.79) and cardiovascular (HR: 2.00; 95% CI: 1.33, 3.00) mortality compared with those reporting the least television viewing (<1 h/d).

CONCLUSIONS

Time spent in sedentary behaviors was positively associated with mortality, and participation in high levels of MVPA did not fully mitigate health risks associated with prolonged time watching television. Adults should be encouraged to reduce time spent in sedentary behaviors, when possible, and to participate in MVPA at recommended levels. The NIH-AARP Diet and Health Study was registered at clinicaltrials.gov as NCT00340015.

Impact of scoring algorithm on physical activity prevalence estimates in Australian adults

Public health recommendations for physical activity are operationalised by defining thresholds for frequency (sessions/week), duration (min/week), or volume (MET-min/week). This study compared estimates of meeting physical activity recommendations when scoring algorithms varied in specifications for frequency and duration but were comparable in volume. Data were obtained from 13,105 Australian adult respondents to the 2006 Exercise, Recreation and Sport Survey (ERASS). Prevalence estimates were calculated using algorithms defined by (i) frequency only (≥5 sessions/week); (ii) duration only (≥150 min/week); (iii) duration only when minutes of vigorous activity were weighted by 2 (≥150 weighted-min/week); (iv) frequency and duration (≥5 sessions/week, ≥150 min/week); (v) volume only (≥600 MET-min/week); and (vi) volume and frequency (≥600 MET-min/week, ≥5 sessions/week). The proportion of adults who met recommendations operationalised without a frequency requirement was twice the proportions obtained for algorithms with frequency requirements. Volume or duration-based algorithms yielded higher estimates for men than women, and for the younger age groups (<35 years) than the older groups, with the opposite observation for frequency-based algorithms. Consistent for all algorithms, people classified at the highest educational attainment had the highest prevalence of meeting recommendations. Agreement in achieving 600 MET-min/week when activities were categorised using activity-specific MET values versus median MET values was 98.3%. Prevalence rates based on 600 MET-min/week were similar to 150 weighted-min/week. In conclusion, varying frequency and duration requirements of scoring algorithms can yield different population estimates and patterns by population subgroup of physical activity for a health benefit.

Neighborhood environments and physical activity among adults in 11 countries

BACKGROUND

Understanding environmental correlates of physical activity can inform policy changes. Surveys were conducted in 11 countries using the same self-report environmental variables and the International Physical Activity Questionnaire, allowing analyses with pooled data.

METHODS

The participating countries were Belgium, Brazil, Canada, Colombia, China (Hong Kong), Japan, Lithuania, New Zealand, Norway, Sweden, and the U.S., with a combined sample of 11,541 adults living in cities. Samples were reasonably representative, and seasons of data collection were comparable. Participants indicated whether seven environmental attributes were present in their neighborhood. Outcomes were measures of whether health-related guidelines for physical activity were met. Data were collected in 2002-2003 and analyzed in 2007. Logistic regression analyses evaluated associations of physical activity with environmental attributes, adjusted for age, gender, and clustering within country.

RESULTS

Five of seven environmental variables were significantly related to meeting physical activity guidelines, ranging from access to low-cost recreation facilities (OR=1.16) to sidewalks on most streets (OR=1.47). A graded association was observed, with the most activity-supportive neighborhoods having 100% higher rates of sufficient physical activity compared to those with no supportive attributes.

CONCLUSIONS

Results suggest neighborhoods built to support physical activity have a strong potential to contribute to increased physical activity. Designing neighborhoods to support physical activity can now be defined as an international public health issue.

The International Prevalence Study on Physical Activity: results from 20 countries

BACKGROUND

Physical activity (PA) is one of the most important factors for improving population health, but no standardised systems exist for international surveillance. The International Physical Activity Questionnaire (IPAQ) was developed for international surveillance. The purpose of this study was a comparative international study of population physical activity prevalence across 20 countries.

METHODS

Between 2002-2004, a standardised protocol using IPAQ was used to assess PA participation in 20 countries [total N = 52,746, aged 18-65 years]. The median survey response rate was 61%. Physical activity levels were categorised as "low", "moderate" and "high". Age-adjusted prevalence estimates are presented by sex.

RESULTS

The prevalence of "high PA" varied from 21-63%; in eight countries high PA was reported for over half of the adult population. The prevalence of "low PA" varied from 9% to 43%. Males more frequently reported high PA than females in 17 of 20 countries. The prevalence of low PA ranged from 7-41% among males, and 6-49% among females. Gender differences were noted, especially for younger adults, with males more active than females in most countries. Markedly lower physical activity prevalence (10% difference) with increasing age was noted in 11 of 19 countries for males, but only in three countries for women. The ways populations accumulated PA differed, with some reporting mostly vigorous intensity activities and others mostly walking.

CONCLUSION

This study demonstrated the feasibility of international PA surveillance, and showed that IPAQ is an acceptable surveillance instrument, at least within countries. If assessment methods are used consistently over time, trend data will inform countries about the success of their efforts to promote physical activity.

Testing a hierarchy-of-effects model: pathways from awareness to outcomes in the VERB campaign 2002-2003

BACKGROUND

The McGuire hierarchy-of-effects (HOE) model, used extensively in mass-media interventions to describe the mechanisms for understanding effects, has not been tested in physical activity campaigns.

DESIGN

Data collected at baseline (2002) and follow-up (2003) surveys in the VERB evaluation were used in structural equation modeling to test pathways and hierarchies of campaign effects.

SETTING/PARTICIPANTS

Population-based cohort of youth aged 9-13 years (N=2364) for whom complete baseline and follow-up data were available.

MAIN OUTCOME MEASURES

Awareness of the VERB campaign, understanding of the VERB message, attitude toward being active, outcome expectations, and physical activity participation.

RESULTS

Among youth aged 9-13 years (tweens) in the study cohort, significant paths were identified between awareness and understanding (0.72, p<0.001) and between understanding and being physically active (0.11, p<0.05). At baseline there was a high prevalence of positive attitudes and outcome expectations, and these were not influenced by change in understanding or awareness. Among inactive tweens only, the same paths were identified except that, in this subgroup, attitude was related to physical activity (0.13, p<0.05), and awareness was more strongly related to physical activity than it was for the whole sample (0.14, p<0.01).

CONCLUSIONS

These findings provided limited support for the HOE model and suggest that increased awareness and understanding were the key proximal effects that led to behavior change. A distinct sequence of effects, which bypassed attitudes and outcome expectations, was found for these U.S. young people. The findings could inform the design of future campaigns to address youth physical activity.

Initial outcomes of the VERB campaign: tweens' awareness and understanding of campaign messages

BACKGROUND

Assessing the immediate effects of mass-media campaigns provides early evidence of campaign reach into the defined target populations. Assessing these effects early in a multi-year campaign allows for better message targeting in subsequent years.

DESIGN

Cross-sectional analysis of a population cohort. Data were collected annually; this paper reports on 1-year outcome data following a mass-media-led intervention to increase physical activity among children aged 9-13 years. The groups initially reached by the campaign and those that understood the campaign messages were identified. Analysis was carried out using logistic regression.

PARTICIPANTS

Nationally representative cohort of 2729 children aged 9-13 years (tweens).

INTERVENTION

National mass-communications campaign (VERB) from June 2002 to June 2003, using television, print, and radio as the primary communication channels. In addition, there were promotions in communities, in schools, and on the Internet.

MAIN OUTCOME MEASURES

Prompted and unprompted awareness of the VERB campaign and understanding of the key campaign message.

RESULTS

After 1 year, tweens' unprompted awareness of VERB was 17.3%; prompted awareness was 57%; 25.6% had no awareness of VERB. Prompted awareness did not differ by child's age, gender, or ethnicity but was associated with being from a middle- or high-income household, having a parent who was a college graduate, and being active on 7 or more days the previous week. Unprompted awareness was significantly associated with being a girl, being aged 12-14 years, being white, being from a moderate- or high-income household, having a parent with a college degree, and doing 7 or more sessions of physical activity during the week before the survey. The variables associated with high levels of understanding of the campaign message were similar to those for campaign awareness, except there were no differences in campaign understanding by age, and a significant association was found between campaign understanding and parental approval of physical activity.

CONCLUSIONS

Measuring initial campaign impact identified the magnitude of immediate effects on population target groups achieved through a mass-media campaign. Campaign planners used the information to develop new messages and adjust media purchases in subsequent years of the VERB campaign.

Associations of type, organization, and number of recreational activities with total activity

BACKGROUND

The aim of this study was to examine the associations between characteristics of recreational activity and total physical activity (PA).

METHODS

Recreational activity type and number were assessed for 3385 adult respondents to the population-based Exercise Recreation and Sport Survey and categorized as "no recreational activity," "walking only," "sport only," or "combined walking and sport." Total PA was assessed by the International Physical Activity Questionnaire and categorized as "low," "moderate," or "high."

RESULTS

Odds of high total PA were 1.7 times greater among walking-only participants, 2.9 times greater among sport-only participants, and 3.3 times greater among participants in combined walking and sport compared to no recreational activity participants. Greater number of recreational activities related to increased odds of high total PA. Similar associations were observed between recreational activity and moderate total PA.

CONCLUSION

Participants in more than 1 type of recreational activity were less likely to have a low-active lifestyle.

Health-related quality of life by level of physical activity in arthritic older adults with and without activity limitations

BACKGROUND

This study examined the association between health-related quality of life (HRQOL) and physical activity (PA) among adults with arthritis.

METHODS

National 2003 Behavioral Risk Factor Surveillance System (BRFSS) survey data for 51,444 adults, age > or = 50 years, with physician-diagnosed arthritis were used to analyze the relationships between PA, self-reported health, HRQOL, and activity limitations related to arthritis.

RESULTS

The percentage of older adults with or without an activity limitation who reported fair/poor health or poor HRQOL was significantly higher in inactive persons compared to those who met PA recommendations (P < .0001). Older adults with and without limitations attaining either recommended or insufficient levels of PA were 39% to 70% less likely to report > or = 14 unhealthy mental or physical days compared to inactive older adults (P < .0001).

CONCLUSION

Participation in PA at the recommended level was strongly associated with improved perceived health and higher levels of HRQOL; however, participation in some PA was clearly better than being inactive. These data were consistent for persons with arthritis despite the presence of an activity limitation.

Walking behaviours from the 1965-2003 American Heritage Time Use Study (AHTUS)

BACKGROUND

The American Heritage Time Use Study (AHTUS) represents a harmonised historical data file of time use by adults, amalgamating surveys collected in 1965-66, 1975-76, 1985, 1992-94, and 2003. The objectives of time-use studies have ranged from evaluating household and other unpaid production of goods and services, to monitoring of media use, to comparing lifestyles of more and less privileged social groups, or to tracking broad shifts in social behaviour. The purpose of this paper is to describe the process and utility of identifying and compiling data from the AHTUS to describe a range of walking behaviours collected using time-use survey methods over almost 40 years in the USA.

METHODS

This is a secondary data analysis of an existing amalgamated data set. Noting source survey-specific limitations in comparability of design, we determined age-standardized participation (and associated durations) in any walking, walking for exercise, walking for transport, walking the dog, sports/exercise (excluding walking), and all physical activity for those survey years for which sufficient relevant data details were available.

RESULTS

Data processing revealed inconsistencies in instrument administration, coding various types of walking and in prompting other sport/exercise across surveys. Thus for the entire period, application of inferential statistics to determine trend for a range of walking behaviours could not be done with confidence. Focusing on the two most comparable survey years, 1985 and 2003, it appears that walking for exercise in America has increased in popularity on any given day (from 2.9 to 5.4% of adults) and accumulated duration amongst those who walk for exercise (from 30 to 45 mins/day). Dog walking has decreased in popularity over the same time period (from 9.4 to 2.6%). Associated duration amongst dog walkers was stable at 30 mins/day.

CONCLUSION

The noted and sometimes substantial differences in methods between the various survey administrations preclude stringent interpretation of these trends in walking behaviours and the use of conventional application of inferential statistics to evaluate significance of time trends. Although the AHTUS offers the most comprehensive attempt at harmonization yet undertaken with these individual time-use surveys, we found that any noted cross-time changes in walking and physical activity behaviour are not easily interpreted in terms of conventional epidemiological approaches and could be true changes, artefact related to instrument and method changes, or both. Public health utilization of the AHTUS, could be enhanced with greater attention to methodological issues known to influence estimation of physical activity behaviour in population. This could be achieved with cross-disciplinary collaboration between groups of experts in the various stages of these surveys.

Construct validity evidence for single-response items to estimate physical activity levels in large sample studies

Valid measurement of physical activity is important for studying the risks for morbidity and mortality. The purpose of this study was to examine evidence of construct validity of two similar single-response items assessing physical activity via self-report. Both items are based on the stages of change model. The sample was 687 participants (men = 504, women = 183) who completed an 8-response (PA8) or 5-response (PA5) single-response item about current level of physical activity. Responses were categorized as meeting or not meeting guidelines for sufficient physical activity to achieve a health benefit. Maximal cardiorespiratory fitness (CRF) and health markers were obtained during a clinical examination. Partial correlation, multivariate analysis of covariance, and logistic regression were used to identify the relations between self-reported physical activity, CRF, and health markers when controlling for gender and age. Single-response items were compared to a detailed measure of physical activity. Single-response items correlated significantly with CRF determined with a maximal exercise test on a treadmill (PA8 = .53; PA5 = .57). Differences in percentage of body fat and cholesterol were in the desired direction, with those self-reporting sufficient physical activity for a health benefit having the lower values. The single-response items demonstrated evidence of construct validity and may provide feasible, cost-effective, and efficient methods to assess physical activity in large-scale studies.

Mass community cycling events: who participates and is their behaviour influenced by participation?

BACKGROUND

Participation in mass physical activity events may be a novel approach for encouraging inactive or low active adults to trial an active behaviour. The public health applicability of this strategy has not been investigated thoroughly. The purpose of this study to was describe participants in a mass cycling event and examine the subsequent effect on cycling behaviour.

METHODS

A sample of men and women aged 16 years and older (n = 918) who registered online for a mass cycling event reported cycling ability and number of times they rode a bicycle during the month before the event. One month after the event participants completed an online follow-up questionnaire and reported cycling ability, lifestyle physical activity, and number of times they rode a bicycle during the month after the event. McNemar's test was used to examine changes in self-rated cycling ability, and repeated measures mixed linear modeling was used to determine whether average number of monthly bicycle rides changed between pre-event and post-event assessment.

RESULTS

Participants in the cycling event were predominantly male (72%), 83% rated themselves as competent or regular cyclists, and 68% rated themselves as more active than others of the same sex and age. Half of the survey respondents that rated their cycling ability as low before the event subsequently rated themselves as high one month after the event. Respondents with low pre-event self-rated cycling ability reported an average 4 sessions of bicycle riding the month before the event and an average 6.8 sessions of bicycle riding a month after the event. This increase in average sessions of bicycle riding was significant (p < .0001). Similarly, first-time participants in this particular cycling event significantly increased average sessions of cycling from 7.2 pre-event to 8.9 sessions one month after the event.

CONCLUSION

Participants who were novice riders or first time participants significantly increased their number of bicycle rides in the month after the event. Further knowledge about the public health applicability of mass events is needed, and methods for attracting less active and novice individuals to participate remain to be developed.

Comparison of the 2001 BRFSS and the IPAQ Physical Activity Questionnaires

PURPOSE

The 2001 Behavioral Risk Factor Surveillance System (BRFSS) physical activity module and the International Physical Activity Questionnaire (IPAQ) are used in population studies to determine the prevalence of physical activity. The comparability of the prevalence estimates has not been compared in U.S. adults. This study compares the physical activity prevalence estimates from the BRFSS and the IPAQ.

METHODS

A telephone survey was administered to a random sample of 11,211 U.S. adults aged 18-99 yr who were enrolled in the National Physical Activity and Weight Loss Survey. Data were analyzed from 9945 adults who provided complete data on the BRFSS and the IPAQ. Prevalence estimates were computed (1) applying the BRFSS scoring scheme for both questionnaires (2). Kappa statistics were used to compare prevalence estimates generated from the BRFSS and the IPAQ.

RESULTS

When scored using the BRFSS protocol, agreement between physical activity categories was fair (kappa = 0.34-0.49). Prevalence estimates were higher on the IPAQ than the BRFSS for the lowest category (inactive) by 0.1-3.9% and for the highest category (meets recommendations) by 0.2-9.7%. When scored using their own scoring, agreement between physical activity categories was lower (kappa = 0.26-0.39). The prevalence estimates on the IPAQ were higher than on the BRFSS for the lowest physical activity category by 0.2-13.3% and for the highest physical activity category by 0-16.4%. Differences in physical activity categories were observed for sex, age, income, education, and body mass index on both questionnaires.

CONCLUSION

Because of differences in the physical activity prevalence estimates, direct comparison of the BRFSS and IPAQ prevalence estimates is not recommended.

Health-related quality of life, BMI and physical activity among US adults (⩾18 years): National Physical Activity and Weight Loss Survey, 2002

OBJECTIVE

To examine the association between health-related quality of life (HRQOL) and physical activity (PA).

METHODS

Cross-sectional data were obtained via a national telephone survey from 9173 respondents (30.9% response rate; 51.4% cooperation rate). Four indicators of HRQOL were measured: self-rated health, physically unhealthy days, mentally unhealthy days and activity limitation days. Prevalence estimates were calculated by body mass index (BMI) category and PA level. Logistic regression evaluated BMI as an effect modifier of the relationship between HRQOL and PA.

RESULTS

Inactive adults reported more fair to poor HRQOL than active adults, regardless of BMI category (P<0.001). BMI did not modify the association between PA and any of the four HRQOL indicators.

CONCLUSION

Prevalence of low HRQOL is inversely related to PA participation, and the relationship is not altered by BMI status. Regardless of their weight status, adults should be encouraged to engage in PA.

Nonoccupational physical activity by degree of urbanization and U.S. geographic region

PURPOSE

To estimate levels of nonoccupational leisure-time physical activity (LTPA) by degree of urbanization and geographic region of the United States.

METHODS

Participants were respondents to the Behavioral Risk Factor Surveillance System (BRFSS) in 2001 (N = 137,359). Moderate- and vigorous-intensity LTPA was categorized as meeting recommended levels, insufficient, or inactive. The U.S. Department of Agriculture rural-urban continuum codes were used to describe degrees of urbanization (metro, large urban, small urban, and rural). Geographic regions were defined by the U.S. Bureau of the Census (Northeast, Midwest, South, and West). Prevalence estimates were calculated using sample weights to account for the design of the BRFSS. Multivariate logistic regression analyses examined regional differences in the odds of physical inactivity (physically inactive vs insufficient or meets) by degree of urbanization after adjustment for sex, age, race, BMI, education, and occupational physical activity.

RESULTS

Large urban areas (49.0%) and the western United States (49.0%) had the highest prevalence of recommended levels of LTPA. Rural areas (24.1%) and the southern United States (17.4%) had the highest prevalence of inactivity. Adults living in the four urbanization categories of the midwestern (metro (OR = 1.47, 95% CI = 1.31, 1.65), large urban (OR = 1.83, 95% CI = 1.51, 2.23), small urban (OR = 1.99, 95% CI = 1.65, 2.40), and rural (OR = 2.59, 95% CI = 1.35, 4.97)); and southern (metro (OR = 1.70, 95% CI = 1.53, 1.88), large urban (OR = 2.04, 95% CI = 1.72, 2.41), small urban (OR = 2.32, 95% CI = 2.02, 2.67), and rural (OR = 5.49, 95% CI = 2.82, 10.68)) U.S. regions were more likely to be inactive than adults living in similar areas of the western United States. Adults in northeast metro and large urban areas (OR = 1.62, 95% CI = 1.45, 1.81; and OR = 1.37, 95% CI = 1.08, 1.74, respectively) were more likely to be inactive than those residing in western metro and large urban areas.

CONCLUSION

The prevalence of physical inactivity varies by degree of urbanization and geographic region of the United States.

Self-reported physical activity among South Carolina adults trying to maintain or lose weight

OBJECTIVES

The obesity epidemic is related to widespread physical inactivity in the United States. This study determined the proportion of South Carolinians trying to maintain or lose weight and within that subpopulation, the number who practiced a restricted diet and engaged in physical activity.

METHODS

Data from the 2002 South Carolina Behavioral Risk Factor Surveillance System survey were used to classify adults who were trying to maintain weight or lose weight. Self-reported prevalence of restricted diet and participation in physical activity were investigated. Of those who reported weight control practices, levels of physical activity were analyzed to determine if those trying to maintain weight or lose weight were meeting the national guidelines for moderate or vigorous physical activity.

RESULTS

More than 70% of South Carolina adults reported trying to control their weight and the majority reported using physical activity for weight control. Though the majority reported use of restricted diet and physical activity, more than one-half of those individuals did not meet the minimum standards for physical activity designed for heart health.

CONCLUSIONS

Although most adults who are trying to maintain or lose weight are participating in physical activity, public health efforts need to focus on encouraging these adults to increase their levels of physical activity to meet the minimum standards for health benefits. Health care providers have an opportunity to educate and encourage patients about the recommended levels of physical activity to obtain maximum health benefits.

Construct validity of self-reported historical physical activity

The purpose of this study was to determine the construct-related validity of self-reported historical walking, running, and jogging (WRJ) activity on the basis of data from the Aerobics Center Longitudinal Study (Dallas, Texas). A total of 4,100 men and 963 women underwent at least one medical examination between 1976 and 1985 and completed a follow-up questionnaire in 1986. Levels of glucose, cholesterol, and triglycerides, resting systolic blood pressure, body mass index (weight (kg)/height (m)(2)), and cardiorespiratory fitness were measured at the time of the medical examination. The follow-up questionnaire assessed WRJ and other strenuous activities for each year from 1976 through 1985. Data analysis included Spearman and partial correlations, analysis of variance, analysis of covariance, and t tests. Results indicated significant correlations between recalled WRJ and treadmill times for each year throughout the 10-year period (r = 0.40-0.61). Participants were classified as historically either sufficiently physically active to receive a health benefit or insufficiently active for a health benefit. Engaging in sufficient levels of historical WRJ was associated with higher treadmill times and lower body mass indices for men and women and lower triglyceride levels for men. Self-reported historical WRJ can be assessed with reasonable validity in comparison with measured treadmill performance, with no decay in accuracy of reporting for up to 10 years in the past.