Schools play an important role in physical activity promotion for adolescents. The systematic review aimed to determine the proportion of secondary (middle and high) school physical education (PE) lesson time that students spend in moderate to vigorous physical activity (MVPA), and to assess if MVPA was moderated by school level (middle and high school), type of physical activity measurement and type of PE activities. A systematic search of nine electronic databases was conducted (PROSPERO2014:CRD42014009649). Studies were eligible if they were published between 2005 and 2014; written in English; assessed MVPA in PE lessons of secondary (middle and high) school students; and used a quantitative MVPA measure (i.e., accelerometry, heart rate monitoring, pedometers or observational measures). Two reviewers examined the retrieved articles, assessed risk of bias, and performed data extraction. Random effects meta-analysis was used to calculate a pooled estimate of the percent of PE lesson time spent in MVPA and to assess moderator effects where data allowed. The search yielded 5,132 potentially relevant articles; 28 articles representing 25 studies (7 middle and 18 high school) from seven countries were included. Twelve studies measured MVPA through observational measures, seven used accelerometers, five used heart rate monitors and four used pedometers (including three studies using a mix of measures). Meta-analysis of 15 studies found that overall, students spent a mean (95% CI) of 40.5% (34.8–46.2%) of PE in MVPA. Middle school students spent 48.6% (41.3–55.9%) of the lesson in MVPA (n = 5 studies) and high school students 35.9% (28.3–43.6%) (n = 10 studies). Studies measuring MVPA using accelerometers (n = 5) showed that students spent 34.7% (25.1–44.4%) of the lesson in MVPA, while 44.4% (38.3–50.5%) was found for lessons assessed via observation (n = 9), 43.1% (24.3–61.9%) of the lesson for a heart rate based study, and 35.9% (31.0–40.8%) for a pedometer-measured study. The proportion of PE spent in MVPA (40.5%) is below the US Centre for Disease Control and Prevention and the UK Associations for Physical Education recommendation of 50%. Findings differed according to the method of MVPA assessment. Additional strategies and intervention research are needed to build more active lesson time in PE.

Background: Nudge interventions are those that seek to modify the social and physical environment to enhance capacity for subconscious behaviours that align with the intrinsic values of an individual, without actively restricting options. This study sought to describe the application and effects of nudge strategies on clinician implementation of health-related guidelines, policies and practices within studies included in relevant Cochrane systematic reviews. Methods: As there is varied terminology used to describe nudge, this study examined studies within relevant systematic reviews. A two-stage screening process was undertaken where, firstly, all systematic reviews published in the Cochrane Library between 2016 and 2018 were screened to identify reviews that included quantitative studies to improve implementation of guidelines among healthcare providers. Secondly, individual studies within relevant systematic reviews were included if they were (i) randomised controlled trials (RCTs), (ii) included a nudge strategy in at least one intervention arm, and (iii) explicitly aimed to improve clinician implementation behaviour. We categorised nudge strategies into priming, salience and affect, default, incentives, commitment and ego, and norms and messenger based on the Mindspace framework. Synthesis: The number and percentage of trials using each nudge strategy was calculated. Due to substantial heterogeneity, we did not undertake a meta-analysis. Instead, we calculated within-study point estimates and 95% confidence intervals, and used a vote-counting approach to explore effects. Results: Seven reviews including 42 trials reporting on 57 outcomes were included. The most common nudge strategy was priming (69%), then norms and messenger (40%). Of the 57 outcomes, 86% had an effect on clinician behaviour in the hypothesised direction, and 53% of those were statistically significant. For continuous outcomes, the median effect size was 0.39 (0.22, 0.45), while for dichotomous outcomes the median Odds Ratio was 1.62 (1.13, 2.76). Conclusions: This review of 42 RCTs included in Cochrane systematic reviews found that the impact of nudge strategies on clinician behaviour was at least comparable to other interventions targeting implementation of evidence-based guidelines. While uncertainty remains, the review provides justification for ongoing investigation of the evaluation and application of nudge interventions to support provider behaviour change. Trial registration: This review was not prospectively registered.

Background: The effectiveness of digital health interventions is commonly assumed to be related to the level of user engagement with the digital health intervention, including measures of both digital health intervention use and users’ subjective experience. However, little is known about the relationships between the measures of digital health intervention engagement and physical activity or sedentary behavior. Objective: This study aims to describe the direction and strength of the association between engagement with digital health interventions and physical activity or sedentary behavior in adults and explore whether the direction of association of digital health intervention engagement with physical activity or sedentary behavior varies with the type of engagement with the digital health intervention (ie, subjective experience, activities completed, time, and logins). Methods: Four databases were searched from inception to December 2019. Grey literature and reference lists of key systematic reviews and journals were also searched. Studies were eligible for inclusion if they examined a quantitative association between a measure of engagement with a digital health intervention targeting physical activity and a measure of physical activity or sedentary behavior in adults (aged ≥18 years). Studies that purposely sampled or recruited individuals on the basis of pre-existing health-related conditions were excluded. In addition, studies were excluded if the individual engaging with the digital health intervention was not the target of the physical activity intervention, the study had a non–digital health intervention component, or the digital health interventions targeted multiple health behaviors. A random effects meta-analysis and direction of association vote counting (for studies not included in meta-analysis) were used to address objective 1. Objective 2 used vote counting on the direction of the association. Results: Overall, 10,653 unique citations were identified and 375 full texts were reviewed. Of these, 19 studies (26 associations) were included in the review, with no studies reporting a measure of sedentary behavior. A meta-analysis of 11 studies indicated a small statistically significant positive association between digital health engagement (based on all usage measures) and physical activity (0.08, 95% CI 0.01-0.14, SD 0.11). Heterogeneity was high, with 77% of the variation in the point estimates explained by the between-study heterogeneity. Vote counting indicated that the relationship between physical activity and digital health intervention engagement was consistently positive for three measures: subjective experience measures (2 of 3 associations), activities completed (5 of 8 associations), and logins (6 of 10 associations). However, the direction of associations between physical activity and time-based measures of usage (time spent using the intervention) were mixed (2 of 5 associations supported the hypothesis, 2 were inconclusive, and 1 rejected the hypothesis). Conclusions: The findings indicate a weak but consistent positive association between engagement with a physical activity digital health intervention and physical activity outcomes. No studies have targeted sedentary behavior outcomes. The findings were consistent across most constructs of engagement; however, the associations were weak.

Background: Prolonged sitting time is a risk factor for chronic disease, yet recent global surveillance is not well described. The aims were to clarify: (i) the countries that have collected country-level data on self-reported sitting time; (ii) the single-item tools used to collect these data; and (iii) the duration of sitting time reported across low- to high-income countries. Methods: Country-level data collected within the last 10 years using single-item self-report were included. The six-stage methodology: (1) reviewing Global Observatory for Physical Activity! Country Cards; (2–4) country-specific searches of PubMed, the Demographic and Health Survey website and Google; (5) analysing the Eurobarometer 88.4; and (6) country-specific searches for World Health Organization STEPwise reports. Results: A total of 7641 records were identified and screened for eligibility. Sixty-two countries (29%) reported sitting time representing 47% of the global adult population. The majority of data were from high-income (61%) and middle income (29%) countries. The tools used were the International Physical Activity Questionnaire (IPAQ; n = 34), a modified IPAQ (n = 1) or the Global Physical Activity Questionnaire (GPAQ; n = 27). The median of mean daily sitting times was 4.7 (IQR: 3.5–5.1) hours across all countries. Higher-income countries recorded a longer duration of sitting time than lower-income countries (4.9 vs 2.7 h). Conclusions: This study provides an updated collation of countries collecting self-reported sitting time data. The daily sitting time findings should be interpreted cautiously. Current surveillance of sitting time is limited by a lack of coverage. Measures of population sitting time that are valid, feasible and sensitive to change should be embedded within global surveillance systems, to help guide future policy, research and practice. Trial registration: Not applicable.