Miriam Wanner

Active Transport, Physical Activity, and Body Weight in Adults: A Systematic Review

CONTEXT Physical activity has various health benefits. Active transport can contribute to total physical activity and thus affect body weight because of increased energy expenditure. This review summarizes published evidence on associations of active transport, general physical activity, and body weight in adults. EVIDENCE ACQUISITION A systematic review of the literature was conducted in October 2010 using eight databases. A total of 14,216 references were screened; full texts were retrieved for 95 articles. Forty-six articles (36 unique studies) were included: 20 (17) from Europe; 18 (13) from North America, Australia, and New Zealand; and eight (six) from other countries. Analyses of the retrieved papers were carried out between November 2010 and March 2011. EVIDENCE SYNTHESIS Of 15 studies assessing active transport and physical activity, five found associations in the expected direction (more active transport associated with more physical activity) for all or most variables studied, nine found some associations, and one reported no associations. Of 30 studies assessing active transport and body weight, 13 reported associations in the expected direction (more active transport associated with lower body weight) for all or most variables studied, 12 found some associations, two presented some associations in the expected and some in the opposite direction, and three reported no associations. CONCLUSIONS There is limited evidence that active transport is associated with more physical activity as well as lower body weight in adults. However, study heterogeneity, predominantly cross-sectional designs, and crude measures for active transport and physical activity impede quantitative conclusions.

Review and special articleActive Transport, Physical Activity, and Body Weight in Adults: A Systematic Review

CONTEXT Physical activity has various health benefits. Active transport can contribute to total physical activity and thus affect body weight because of increased energy expenditure. This review summarizes published evidence on associations of active transport, general physical activity, and body weight in adults. EVIDENCE ACQUISITION A systematic review of the literature was conducted in October 2010 using eight databases. A total of 14,216 references were screened; full texts were retrieved for 95 articles. Forty-six articles (36 unique studies) were included: 20 (17) from Europe; 18 (13) from North America, Australia, and New Zealand; and eight (six) from other countries. Analyses of the retrieved papers were carried out between November 2010 and March 2011. EVIDENCE SYNTHESIS Of 15 studies assessing active transport and physical activity, five found associations in the expected direction (more active transport associated with more physical activity) for all or most variables studied, nine found some associations, and one reported no associations. Of 30 studies assessing active transport and body weight, 13 reported associations in the expected direction (more active transport associated with lower body weight) for all or most variables studied, 12 found some associations, two presented some associations in the expected and some in the opposite direction, and three reported no associations. CONCLUSIONS There is limited evidence that active transport is associated with more physical activity as well as lower body weight in adults. However, study heterogeneity, predominantly cross-sectional designs, and crude measures for active transport and physical activity impede quantitative conclusions.

Comparison of trial participants and open access users of a web-based physical activity intervention regarding adherence, attrition, and repeated participation

Background Web-based interventions are popular for promoting healthy lifestyles such as physical activity. However, little is known about user characteristics, adherence, attrition, and predictors of repeated participation on open access physical activity websites. Objective The focus of this study was Active-online, a Web-based individually tailored physical activity intervention. The aims were (1) to assess and compare user characteristics and adherence to the website (a) in the open access context over time from 2003 to 2009, and (b) between trial participants and open access users; and (2) to analyze attrition and predictors of repeated use among participants in a randomized controlled trial compared with registered open access users. Methods Data routinely recorded in the Active-online user database were used. Adherence was defined as: the number of pages viewed, the proportion of visits during which a tailored module was begun, the proportion of visits during which tailored feedback was received, and the time spent in the tailored modules. Adherence was analyzed according to six one-year periods (2003-2009) and according to the context (trial or open access) based on first visits and longest visits. Attrition and predictors of repeated participation were compared between trial participants and open access users. Results The number of recorded visits per year on Active-online decreased from 42,626 in 2003-2004 to 8343 in 2008-2009 (each of six one-year time periods ran from April 23 to April 22 of the following year). The mean age of users was between 38.4 and 43.1 years in all time periods and both contexts. The proportion of women increased from 49.5% in 2003-2004 to 61.3% in 2008-2009 (P< .001). There were differences but no consistent time trends in adherence to Active-online. The mean age of trial participants was 43.1 years, and 74.9% were women. Comparing contexts, adherence was highest for registered open access users. For open access users, adherence was similar during the first and the longest visits; for trial participants, adherence was lower during the first visits and higher during the longest visits. Of registered open access users and trial participants, 25.8% and 67.3% respectively visited Active-online repeatedly (P< .001). Predictors of repeated use were male sex (odds ratio [OR] = 1.2, 95% confidence interval [CI] = 1.04-1.38) and increasing age category in registered open access users, and age 46-60 versus < 30 years (OR = 3.04, 95% CI = 1.25-7.38) and Swiss nationality (ORnonSwiss= 0.64, 95% CI = 0.41-1.00) in trial participants. Despite reminder emails, attrition was much higher in registered open access users compared with trial participants, with a median lifetime website usage of 0 days in open access users and 290 days in trial participants. Conclusions Adherence, patterns of use, attrition, and repeated participation differed between trial participants and open access users. Reminder emails to encourage repeated participation were effective for trial participants but not for registered open access users. These issues are important when interpreting results of randomized controlled effectiveness trials.

Effectiveness of Active-Online, an Individually Tailored Physical Activity Intervention, in a Real-Life Setting: Randomized Controlled Trial

Background Effective interventions are needed to reduce the chronic disease epidemic. The Internet has the potential to provide large populations with individual advice at relatively low cost. Objective The focus of the study was the Web-based tailored physical activity intervention Active-online. The main research questions were (1) How effective is Active-online, compared to a nontailored website, in increasing self-reported and objectively measured physical activity levels in the general population when delivered in a real-life setting? (2) Do respondents recruited for the randomized study differ from spontaneous users of Active-online, and how does effectiveness differ between these groups? (3) What is the impact of frequency and duration of use of Active-online on changes in physical activity behavior? Methods Volunteers recruited via different media channels completed a Web-based baseline survey and were randomized to Active-online (intervention group) or a nontailored website (control group). In addition, spontaneous users were recruited directly from the Active-online website. In a subgroup of participants, physical activity was measured objectively using accelerometers. Follow-up assessments took place 6 weeks (FU1), 6 months (FU2), and 13 months (FU3) after baseline. Results A total of 1531 respondents completed the baseline questionnaire (intervention group n = 681, control group n = 688, spontaneous users n = 162); 133 individuals had valid accelerometer data at baseline. Mean age of the total sample was 43.7 years, and 1146 (74.9%) were women. Mixed linear models (adjusted for sex, age, BMI category, and stage of change) showed a significant increase in self-reported mean minutes spent in moderate- and vigorous-intensity activity from baseline to FU1 (coefficient = 0.14, P = .001) and to FU3 (coefficient = 0.19, P < .001) in all participants with no significant differences between groups. A significant increase in the proportion of individuals meeting the HEPA recommendations (self-reported) was observed in all participants between baseline and FU3 (OR = 1.47, P = .03), with a higher increase in spontaneous users compared to the randomized groups (interaction between FU3 and spontaneous users, OR = 2.95, P = .02). There were no increases in physical activity over time in any group for objectively measured physical activity. A significant relation was found between time spent on the tailored intervention and changes in self-reported physical activity between baseline and FU3 (coefficient = 1.13, P = .03, intervention group and spontaneous users combined). However, this association was no longer significant when adjusting for stage of change. Conclusions In a real-life setting, Active-online was not more effective than a nontailored website in increasing physical activity levels in volunteers from the general population. Further research may investigate ways of integrating Web-based physical activity interventions in a wider context, for example, primary care or workplace health promotion.

What physical activity surveillance needs: validity of a single-item questionnaire

Background Self-report instruments to assess physical activity are still the most feasible option in many population-wide surveys, and often need to be very short owing to resource constraints. The aim of this study was to test the criterion validity of a single-item physical activity measure using accelerometers and to compare its measurement properties by gender, age group (including older adults) and language region. Methods A validation study was carried out within the second follow-up of a large Swiss cohort study (Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults, SAPALDIA, n=208) and included an additional convenient sample (n=110). Participants wore an accelerometer over eight consecutive days and then completed the single-item measure. Spearmans rank-order correlations were used to assess the criterion validity. Results Physical activity levels were higher in men, younger individuals and those from the German-speaking part of Switzerland. Correlation coefficients for the number of days with at least 30 min of moderate-to-vigorous physical activity according to the single item and different accelerometer activity outcomes ranged from 0.40 to 0.54. Correlations were higher for women, younger individuals and participants from the French-speaking and the Italian-speaking parts. Conclusions The single-item physical activity measure performed at least as well as other physical activity questionnaires. The differences in criterion validity between sub groups indicate that factors such as gender and age should be taken into account when developing physical activity questionnaires and in future validation studies.

Effects of leisure-time and occupational physical activity on total mortality risk in NHANES III according to sex, ethnicity, central obesity, and age.

BACKGROUND Associations of physical activity with all-cause mortality seem to be quite strong, but little is known about potential effect modifiers as sex, race/ethnicity, age, and obesity. METHODS Data of the Third National Health and Nutrition Examination Survey (NHANES III), conducted 1988-1994 with mortality follow-up until 2006, were used to compare mortality risk between different levels of leisure-time physical activity (LTPA) and occupational physical activity (OPA). Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS LTPA (n = 15,307) was inversely associated with all-cause mortality (HR 0.75, 95% CI 0.64-0.88 for regular vs. no LTPA). There was a statistically significant interaction with age (P = .03), with participants over 60 years of age benefitting more from regular or irregular LTPA. OPA was positively associated with all-cause mortality (HR 1.25, 95% CI 0.85-1.84 for high vs. low OPA), particularly among Mexican-Americans (HR 2.28, 95% CI 1.23-4.22); statistically significant interactions were observed for obesity and gender. CONCLUSIONS LTPA clearly predicts all-cause mortality. However, associations between OPA and all-cause mortality are unclear and need further research with special regard to ethnic differences.

Effects of filter choice in GT3X accelerometer assessments of free-living activity

PURPOSE ActiGraph accelerometers are widely used devices to objectively assess physical activity. The GT3X version has two filter options to be selected before data assessment (normal and low-frequency extension filter option). It is not clear whether the resulting physical activity levels differ depending on the choice of the filter. The aims were to compare GT3X data collected using the different filter options during free-living activities and to establish correction factors if the results were not comparable. METHODS Sixty-five participants of the population-based SAPALDIA-cohort (50.8% women, age range = 40-80 yr) wore two GT3X accelerometers with different filter selections simultaneously during 8 d. Spearman correlations, Wilcoxon rank sum tests, McNemar tests, scatter plots, and Bland-Altman plots were used to compare the data. Correction factors were established using linear regression models. RESULTS Although Spearman correlations were high (r ≥ 0.93), there were significant differences in minutes per day between filter options for nonwearing time and time spent in sedentary, light, and moderate-to-vigorous physical activity (all P < 0.001), with more remarkable differences in the lower range of activity (sedentary and light activities). Mean counts per minute and steps per day were significantly higher using the low-frequency extension filter (P < 0.001). Most differences could be resolved using the correction factors. CONCLUSIONS The observed differences are especially important when research is focusing on sedentary and light activities. In future studies, it is important to carefully evaluate the suitable filter option and to specify the filter choice in publications. The correction factors can be used to make data assessed using the low-frequency extension filter comparable to data assessed using the normal filter option.

Validation of the long international physical activity questionnaire: Influence of age and language region

Objective Little is known about the influence of age, gender and language on the measurement properties of the long International Physical Activity Questionnaire (IPAQ). The aim was to validate the long IPAQ in adults aged 18–84 in the German-, French- and Italian-speaking parts of Switzerland, focusing on differences between gender, age groups and language regions. Methods This cross-sectional study was conducted in the frame of SAPALDIA (Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults) in 2011. 346 participants (54.6% women, mean age 54.6 years) wore an Actigraph GT3X accelerometer during 8 days and completed the IPAQ. IPAQ and accelerometer data on total physical activity and on different intensities as well as sitting time were compared using Spearman correlations and Bland–Altman plots. Results Correlations were highest for vigorous physical activity (r = 0.41) and sitting time (r = 0.42). Significant gender differences were apparent for leisure-time physical activity (men: r = 0.35 versus women: r = 0.57, p = 0.012) and for sitting time (men: r = 0.28 versus women: r = 0.53, p = 0.007). Differences between age groups were present for sitting time (youngest: r = 0.72 versus middle: r = 0.36, p < 0.001; youngest versus oldest: r = 0.34, p = 0.001). Differences between language regions were present for vigorous physical activity (German: r = 0.28 versus Italian: r = 0.53, p = 0.033). IPAQ overestimated physical activity but underestimated sitting time. Conclusion The long IPAQ showed moderate validity similar to other studies when compared to accelerometer data in a diverse sample of individuals. Some sex, age and regional differences were observed but do not seem to limit its applicability in population sub groups.

Long-term transportation noise annoyance is associated with subsequent lower levels of physical activity.

Noise annoyance (NA) might lead to behavioral patterns not captured by noise levels, which could reduce physical activity (PA) either directly or through impaired sleep and constitute a noise pathway towards cardiometabolic diseases. We investigated the association of long-term transportation NA and its main sources (aircraft, road, and railway) at home with PA levels. We assessed 3842 participants (aged 37-81) that attended the three examinations (SAP 1, 2, and 3 in years 1991, 2001 and 2011, respectively) of the population-based Swiss cohort on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). Participants reported general 24-h transportation NA (in all examinations) and source-specific NA at night (only SAP 3) on an ICBEN-type 11-point scale. We assessed moderate, vigorous, and total PA from a short-questionnaire (SAP 3). The main outcome was moderate PA (active/inactive: cut-off≥150min/week). We used logistic regression including random effects by area and adjusting for age, sex, socioeconomic status, and lifestyles (main model) and evaluated potential effect modifiers. We analyzed associations with PA at SAP 3 a) cross-sectionally: for source-specific and transportation NA in the last year (SAP 3), and b) longitudinally: for 10-y transportation NA (mean of SAP 1+2), adjusting for prior PA (SAP 2) and changes in NA (SAP 3-2). Reported NA (score≥5) was 16.4%, 7.5%, 3%, and 1.1% for 1-year transportation, road, aircraft, and railway at SAP 3, respectively. NA was greater in the past, reaching 28.5% for 10-y transportation NA (SAP 1+2). The 10-y transportation NA was associated with a 3.2% (95% CI: 6%-0.2%) decrease in moderate PA per 1-NA rating point and was related to road and aircraft NA at night in cross-sectional analyses. The longitudinal association was stronger for women, reported daytime sleepiness or chronic diseases and it was not explained by objectively modeled levels of road traffic noise at SAP 3. In conclusion, long-term NA (related to psychological noise appraisal) reduced PA and could represent another noise pathway towards cardiometabolic diseases.

Impact of different domains of physical activity on cause-specific mortality: A longitudinal study

OBJECTIVE The aim of this paper is to examine the associations between different domains of physical activity and all-cause, cardiovascular disease (CVD) and cancer mortality. METHODS Participants (n=17,663, aged 16-92 years) of two general population health studies conducted between 1977 and 1993 in Switzerland were included. Physical activity was assessed at baseline in the domains of commuting to work, work-related physical activity, and leisure-time physical activity (including leisure-time activity level and sport activity). A median follow-up time of 20.2 years was obtained with anonymous record linkage providing 3878 deaths (CVD: 1357; cancer: 1351). Adjusted Cox proportional hazard models were calculated. RESULTS There were no significant associations between commuting and work-related physical activities, respectively, and mortality. Leisure-time activity level was associated with all-cause mortality in men [adjusted hazard ratio (HR) 0.75, 95% confidence intervals (CI) 0.63-0.89] and women [HR 0.82 (0.74-0.91)], with CVD mortality in women only [HR 0.79 (0.67-0.94)] and with cancer mortality in men only [HR 0.63 (0.47-0.86)]. Sport activity was associated with all-cause, CVD and cancer mortality in men [HR ranged between 0.76 (0.63-0.92) and 0.85 (0.76-0.95)], but not in women. CONCLUSIONS These results underline the public health relevance of physical activity for the prevention of CVD and cancer, especially regarding leisure-time physical activity.