Cross-Sectional Associations between Home Environmental Factors and Domain-Specific Sedentary Behaviors in Adults: The Moderating Role of Socio-Demographic Variables and BMI.

Despite the negative health effects of too much sitting, the majority of adults are too sedentary. To develop effective interventions, insight is needed into home environmental correlates of adults' sedentary behaviors, and into the susceptibility of population subgroups to these home environmental cues. In total, 559 Flemish adults reported socio-demographics, weight and height, home environmental factors and domain-specific sedentary behaviors. Generalized linear modeling was conducted to examine main associations between home environmental factors and domain-specific sedentary behaviors, and to test the moderating role of socio-demographics and BMI on these associations. In case of significant interactions, stratified analyses were performed. Results showed that, among those who did use a computer/laptop during the last week, a one-unit increase in the number of computers or laptops was associated with 17% (OR = 1.17; 95% CI = 1.02, 1.34) and 24% (OR = 1.24; 95% CI = 1.08, 1.43) more minutes computer time per day, respectively. The proximity of the remote controller (p < 0.001) and the number of televisions (p = 0.03) were positively associated with television time, and the number of motorized vehicles (95% CI = 0.001, 0.12) was positively associated with the odds of participation in transport-related sitting time. The latter two associations were moderated by BMI, with significant positive associations limited to those not overweight. To conclude, home environmental factors were associated with domain-specific sedentary behaviors, especially in healthy weight adults. If confirmed by longitudinal studies, public health professionals should encourage adults to limit the number of indoor entertainment devices and motorized vehicles.

Socio-Ecological Variables Associated with Context-Specific Sitting Time in Belgian Older Adults: A One-Year Follow-Up Study.

INTRODUCTION: Knowledge about variables associated with context-specific sitting time in older adults is limited. Therefore, this study explored cross-sectional and longitudinal associations of socio-demographic, social-cognitive, physical-environmental and health-related variables with sitting during TV viewing, computer use and motorized transport in older adults. METHODS: A sample of Belgian older adults completed structured interviews on context-specific sitting time and associated variables using a longitudinal study design. Objective measurements of grip strength and physical performance were also completed. Complete baseline data were available of 258 participants (73.98±6.16 years) of which 229 participants remained in the study at one year follow-up (retention rate: 91.60%). Cross-sectional correlates (baseline data) and longitudinal predictors (change-scores in relation with change in sitting time) were explored through multiple linear regression analyses. RESULTS: Per context-specific sitting time, most of the cross-sectional correlates differed from the longitudinal predictors. Increases over time in enjoyment of watching TV (+one unit), encouragement of partner to watch less TV (+one unit) and TV time of partner (+30.0 min/day) were associated with respectively 9.1 min/day (p<0.001), 16.0 min/day (p<0.001) and 12.0 min/day (p<0.001) more sitting during TV viewing at follow-up. Increases over time in enjoyment of using a computer (+one unit), the number of smartphones and tablets (+1) and computer use of the partner (+30.0 min/day) were associated with respectively 5.5 min/day (p < .01), 10.4 min/day (p < .05) and 3.0 min/day (p < .05) more sitting during computer use at follow-up. An increase over time in self-efficacy regarding taking a bicycle or walking was associated with 2.9 min/day (p < .05) less sitting during motorized transport at follow-up. CONCLUSIONS: The results stressed the importance of looking at separate contexts of sitting. Further, the results highlighted the importance of longitudinal research in order to reveal which changes in particular variables predicted changes in context-specific sitting time. Variables at the social-cognitive level were most frequently related to context-specific sitting.

Socio-Demographic, Social-Cognitive, Health-Related and Physical Environmental Variables Associated with Context-Specific Sitting Time in Belgian Adolescents: A One-Year Follow-Up Study.

INTRODUCTION: More knowledge is warranted about multilevel ecological variables associated with context-specific sitting time among adolescents. The present study explored cross-sectional and longitudinal associations of ecological domains of sedentary behaviour, including socio-demographic, social-cognitive, health-related and physical-environmental variables with sitting during TV viewing, computer use, electronic gaming and motorized transport among adolescents. METHODS: For this longitudinal study, a sample of Belgian adolescents completed questionnaires at school on context-specific sitting time and associated ecological variables. At baseline, complete data were gathered from 513 adolescents (15.0±1.7 years). At one-year follow-up, complete data of 340 participants were available (retention rate: 66.3%). Multilevel linear regression analyses were conducted to explore cross-sectional correlates (baseline variables) and longitudinal predictors (change scores variables) of context-specific sitting time. RESULTS: Social-cognitive correlates/predictors were most frequently associated with context-specific sitting time. Longitudinal analyses revealed that increases over time in considering it pleasant to watch TV (p < .001), in perceiving TV watching as a way to relax (p < .05), in TV time of parents/care givers (p < .01) and in TV time of siblings (p < .001) were associated with more sitting during TV viewing at follow-up. Increases over time in considering it pleasant to use a computer in leisure time (p < .01) and in the computer time of siblings (p < .001) were associated with more sitting during computer use at follow-up. None of the changes in potential predictors were significantly related to changes in sitting during motorized transport or during electronic gaming. CONCLUSIONS: Future intervention studies aiming to decrease TV viewing and computer use should acknowledge the importance of the behaviour of siblings and the pleasure adolescents experience during these screen-related behaviours. In addition, more time parents or care givers spent sitting may lead to more sitting during TV viewing of the adolescents, so that a family-based approach may be preferable for interventions. Experimental study designs are warranted to confirm the present findings.

Intrapersonal, social-cognitive and physical environmental variables related to context-specific sitting time in adults: a one-year follow-up study.

BACKGROUND: Investigating associations between socio-ecological variables and context-specific sitting time in adults can support the development of future interventions. The purpose of the present study was to examine the cross-sectional and longitudinal relationships of intrapersonal, social-cognitive and physical environmental variables with context-specific sitting time (i.e. TV-viewing, computer use, motorized transport, and occupational sitting) in adults. METHODS: In this longitudinal study, data were retrieved from a random sample of Flemish (Belgian) adults. At baseline, 301 adults (age, 43.3 ± 10.6 years) completed a questionnaire on context-specific sitting time and its potential predictors. After a 1-year follow-up period, complete data of 188 adults was available (age, 46.0 ± 10.4 years). Multiple linear regression analyses were performed for both the cross-sectional data at baseline (correlates) and the longitudinal data (predictors). RESULTS: The cross-sectional and longitudinal analyses revealed different relationships between sitting during TV viewing, computer use, motorized transport and occupation. Generally, change in cross-sectional correlates did not cause change in context-specific sitting time in the longitudinal analyses. Social-cognitive correlates/predictors were most frequently identified, followed by intrapersonal correlates/predictors. Attitude, self-efficacy, (social) norm and modelling were found to be the most consistently related social-cognitive correlates/predictors to context-specific sitting time. Limited evidence was available for relationships between physical environmental variables and context-specific sitting time. CONCLUSIONS: The cross-sectional correlates differed from the longitudinal predictors of context-specific sitting time, highlighting the need for longitudinal research. The present study also underlined the need for family interventions to minimize context-specific sitting time, as both intrapersonal and social-cognitive variables were associated with context-specific sitting time.

Reliability and validity of three questionnaires measuring context-specific sedentary behaviour and associated correlates in adolescents, adults and older adults.

BACKGROUND: Reliable and valid measures of total sedentary time, context-specific sedentary behaviour (SB) and its potential correlates are useful for the development of future interventions. The purpose was to examine test-retest reliability and criterion validity of three newly developed questionnaires on total sedentary time, context-specific SB and its potential correlates in adolescents, adults and older adults. METHODS: Reliability and validity was tested in six different samples of Flemish (Belgium) residents. For the reliability study, 20 adolescents, 22 adults and 20 older adults filled out the age-specific SB questionnaire twice. Test-retest reliability was analysed using Kappa coefficients, Intraclass Correlation Coefficients and/or percentage agreement, separately for the three age groups. For the validity study, data were retrieved from 62 adolescents, 33 adults and 33 older adults, with activPAL™ as criterion measure. Spearman correlations and Bland-Altman plots (or non-parametric approach) were used to analyse criterion validity, separately for the three age groups and for weekday, weekend day and average day. RESULTS: The test-retest reliability for self-reported total sedentary time indicated following values: ICC = 0.37-0.67 in adolescents; ICC = 0.73-0.77 in adults; ICC = 0.68-0.80 in older adults. Item-specific reliability results (e.g. context-specific SB and its potential correlates) showed good-to-excellent reliability in 67.94%, 68.90% and 66.38% of the items in adolescents, adults and older adults respectively. All items belonging to sedentary-related equipment and simultaneous SB showed good reliability. The sections of the questionnaire with lowest reliability were: context-specific SB (adolescents), potential correlates of computer use (adults) and potential correlates of motorized transport (older adults). Spearman correlations between self-reported total sedentary time and the activPAL™ were different for each age group: ρ = 0.02-0.42 (adolescents), ρ = 0.06-0.52 (adults), ρ = 0.38-0.50 (older adults). Participants over-reported total sedentary time (except for weekend day in older adults) compared to the activPAL™, for weekday, weekend day and average day respectively by +57.05%, +46.29%, +53.34% in adolescents; +40.40%, +19.15%, +32.89% in adults; +10.10%, -6.24%, +4.11% in older adults. CONCLUSIONS: The questionnaires showed acceptable test-retest reliability and criterion validity. However, over-reporting of total SB was noticeable in adolescents and adults. Nevertheless, these questionnaires will be useful in getting context-specific information on SB.

Tracking and predictors of screen time from early adolescence to early adulthood: a 10-year follow-up study.

PURPOSE: To examine tracking of weekday and weekend screen time (ST; i.e., television [TV] and computer [PC] time) from early adolescence to early adulthood and to identify social ecological predictors of weekday and weekend ST among boys and girls separately. METHODS: Data were retrieved from elementary schools (n = 59) in Flanders (Belgium). At baseline, 1,957 children (age, 9.9 ± .43 years) and one of the parents filled out a questionnaire on sedentary behavior and individual, social, and environmental variables. After a 10-year follow-up period, six hundred fifty-five 20-year-olds (age, 19.9 ± .43 years) filled out an adapted questionnaire on sedentary behavior, of which 593 contained full data at baseline and follow-up. Multiple regressions were performed to examine predictors (baseline) of ST (follow-up), and logistic regressions were used to analyze tracking of ST. RESULTS: For boys, a consistent positive predictor of weekday and weekend TV and PC time at follow-up was ST at baseline (p < .01). For girls, drinking more soda at baseline predicted more weekday and weekend TV and PC time at follow-up (p ≤ .02). Some other individual variables also predicted ST in both boys and girls. Tracking was only found among boys; those exceeding the ST guideline at baseline were three to five times more likely to exceed this guideline at follow-up (p ≤ .001). Tracking was not present among girls. CONCLUSIONS: To minimize TV and PC time during early adulthood, interventions for adolescent boys should focus on minimizing ST. For girls, focus should be on healthy eating. However, more research is warranted to confirm these conclusions.