BackgroundThe dramatic growth of Web 2.0 technologies and online social networks offers immense potential for the delivery of health behavior change campaigns. However, it is currently unclear how online social networks may best be harnessed to achieve health behavior change.ObjectiveThe intent of the study was to systematically review the current level of evidence regarding the effectiveness of online social network health behavior interventions.MethodsEight databases (Scopus, CINAHL, Medline, ProQuest, EMBASE, PsycINFO, Cochrane, Web of Science and Communication & Mass Media Complete) were searched from 2000 to present using a comprehensive search strategy. Study eligibility criteria were based on the PICOS format, where “population” included child or adult populations, including healthy and disease populations; “intervention” involved behavior change interventions targeting key modifiable health behaviors (tobacco and alcohol consumption, dietary intake, physical activity, and sedentary behavior) delivered either wholly or in part using online social networks; “comparator” was either a control group or within subject in the case of pre-post study designs; “outcomes” included health behavior change and closely related variables (such as theorized mediators of health behavior change, eg, self-efficacy); and “study design” included experimental studies reported in full-length peer-reviewed sources. Reports of intervention effectiveness were summarized and effect sizes (Cohen’s d and 95% confidence intervals) were calculated wherever possible. Attrition (percentage of people who completed the study), engagement (actual usage), and fidelity (actual usage/intended usage) with the social networking component of the interventions were scrutinized.ResultsA total of 2040 studies were identified from the database searches following removal of duplicates, of which 10 met inclusion criteria. The studies involved a total of 113,988 participants (ranging from n=10 to n=107,907). Interventions included commercial online health social network websites (n=2), research health social network websites (n=3), and multi-component interventions delivered in part via pre-existing popular online social network websites (Facebook n=4 and Twitter n=1). Nine of the 10 included studies reported significant improvements in some aspect of health behavior change or outcomes related to behavior change. Effect sizes for behavior change ranged widely from −0.05 (95% CI 0.45-0.35) to 0.84 (95% CI 0.49-1.19), but in general were small in magnitude and statistically non-significant. Participant attrition ranged from 0-84%. Engagement and fidelity were relatively low, with most studies achieving 5-15% fidelity (with one exception, which achieved 105% fidelity).ConclusionsTo date there is very modest evidence that interventions incorporating online social networks may be effective; however, this field of research is in its infancy. Further research is needed to determine how to maximize retention and engagement, whether behavior change can be sustain...

This study provides the largest and most geographically representative sex-specific and age-specific European normative values for children and adolescents, which have utility for health and fitness screening, profiling, monitoring and surveillance.

The health effects of daily activity behaviours (physical activity, sedentary time and sleep) are widely studied. While previous research has largely examined activity behaviours in isolation, recent studies have adjusted for multiple behaviours. However, the inclusion of all activity behaviours in traditional multivariate analyses has not been possible due to the perfect multicollinearity of 24-h time budget data. The ensuing lack of adjustment for known effects on the outcome undermines the validity of study findings. We describe a statistical approach that enables the inclusion of all daily activity behaviours, based on the principles of compositional data analysis. Using data from the International Study of Childhood Obesity, Lifestyle and the Environment, we demonstrate the application of compositional multiple linear regression to estimate adiposity from children's daily activity behaviours expressed as isometric log-ratio coordinates. We present a novel method for predicting change in a continuous outcome based on relative changes within a composition, and for calculating associated confidence intervals to allow for statistical inference. The compositional data analysis presented overcomes the lack of adjustment that has plagued traditional statistical methods in the field, and provides robust and reliable insights into the health effects of daily activity behaviours.

How people use their time has been linked with their health. For example, spending more time being physically active is known to be beneficial for health, whereas long durations of sitting have been associated with unfavourable health outcomes. Accordingly, public health messages have advocated swapping strategies to promote the reallocation of time between parts of the time-use composition, such as "Move More, Sit Less", with the aim of achieving optimal distribution of time for health. However, the majority of research underpinning these public health messages has not considered daily time use as a composition, and has ignored the relative nature of time-use data. We present a way of applying compositional data analysis to estimate change in a health outcome when fixed durations of time are reallocated from one part of a particular time-use composition to another, while the remaining parts are kept constant, based on a multiple linear regression model on isometric log ratio coordinates. In an example, we examine the expected differences in Body Mass Index z-scores for reallocations of time between sleep, physical activity and sedentary behaviour.

BackgroundThe majority of reporting guidelines assist researchers to report consistent information concerning study design, however, they contain limited information for describing study interventions. Using a three-stage development process, the Guideline for Reporting Evidence-based practice Educational interventions and Teaching (GREET) checklist and accompanying explanatory paper were developed to provide guidance for the reporting of educational interventions for evidence-based practice (EBP). The aim of this study was to complete the final development for the GREET checklist, incorporating psychometric testing to determine inter-rater reliability and criterion validity.MethodsThe final development for the GREET checklist incorporated the results of a prior systematic review and Delphi survey. Thirty-nine items, including all items from the prior systematic review, were proposed for inclusion in the GREET checklist. These 39 items were considered over a series of consensus discussions to determine the inclusion of items in the GREET checklist. The GREET checklist and explanatory paper were then developed and underwent psychometric testing with tertiary health professional students who evaluated the completeness of the reporting in a published study using the GREET checklist. For each GREET checklist item, consistency (%) of agreement both between participants and the consensus criterion reference measure were calculated. Criterion validity and inter-rater reliability were analysed using intra-class correlation coefficients (ICC).ResultsThree consensus discussions were undertaken, with 14 items identified for inclusion in the GREET checklist. Following further expert review by the Delphi panelists, three items were added and minor wording changes were completed, resulting in 17 checklist items. Psychometric testing for the updated GREET checklist was completed by 31 participants (n = 11 undergraduate, n = 20 postgraduate). The consistency of agreement between the participant ratings for completeness of reporting with the consensus criterion ratings ranged from 19 % for item 4 Steps of EBP, to 94 % for item 16 Planned delivery. The overall consistency of agreement, for criterion validity (ICC 0.73) and inter-rater reliability (ICC 0.96), was good to almost perfect.ConclusionThe final GREET checklist comprises 17 items which are recommended for reporting EBP educational interventions. Further validation of the GREET checklist with experts in EBP research and education is recommended.Electronic supplementary materialThe online version of this article (doi:10.1186/s12909-016-0759-1) contains supplementary material, which is available to authorized users.