This meta-analysis explored the efficacy of the Theory of Planned Behaviour (TPB) dependent on behaviour and methodological moderators. A lack of hierarchical analysis in previous reviews risks confounding these moderators. Here moderating roles of behaviour type, length of follow-up, sample age and behavioural measure are explored hierarchically amongst prospective tests of the TPB, controlling for past behaviour where possible. Searching identified 237 prospective tests from 206 articles. Random-effects meta-analytic procedures were used to correcting correlations for sampling and measurement error. Behaviour type moderated the model; physical activity and diet behaviours were better predicted (23.9% and 21.2% variance explained, respectively) whilst risk, detection, safer sex and abstinence from drugs were poorly predicted (between 13.8 and 15.3% variance explained). Methodological moderators were also apparent: age of sample moderated relations with student samples better predicted for physical activity, and adolescent samples better predicted for abstinence behaviours. Behaviours assessed in the shorter term, and those assessed with self-reports (compared with objective measures) were also better predicted. Both behavioural and methodological characteristics moderated relations amongst model components. The results can aid selection of appropriate targets upon which to base interventions.

BackgroundReasoned action approach (RAA) includes subcomponents of attitude (experiential/instrumental), perceived norm (injunctive/descriptive), and pe

Mental health problems are associated with lower quality of life, increased unscheduled care, high economic and social cost, and increased mortality. Nature-based interventions (NBIs) that support people to engage with nature in a structured way are asset-based solutions to improve mental health for community based adults. However, it is unclear which NBIs are most effective, or what format and dose is most efficacious. We systematically reviewed the controlled and uncontrolled evidence for outdoor NBIs. The protocol was registered at PROSPERO (CRD42020163103). Studies that included adults (aged ≥18 years) in community-based settings with or without mental and/or physical health problems were eligible for inclusion. Eligible interventions were structured outdoor activities in green and/or blue space for health and wellbeing. We searched ASSIA, CENTRAL, Embase, Greenfile, MEDLINE, PsycINFO, and Web of Science in October 2019; the search was updated in September 2020. We screened 14,321 records and included 50 studies. Sixteen studies were randomised controlled trials (RCTs); 18 were controlled studies; and 16 were uncontrolled before and after studies. Risk of bias for RCTs was low to moderate; and moderate to high for controlled and uncontrolled studies. Random effects meta-analysis of RCTs showed that NBIs were effective for improving depressive mood −0.64 (95% CI: 1.05 to −0.23), reducing anxiety −0.94 (95% CI: 0.94 to −0.01), improving positive affect 0.95 (95% CI: 0.59 to 1.31), and reducing negative affect −0.52 (95% CI: 0.77 to −0.26). Results from controlled and uncontrolled studies largely reflected findings from RCTs. There was less evidence that NBIs improved physical health. The most effective interventions were offered for between 8 and 12 weeks, and the optimal dose ranged from 20 to 90 min. NBIs, specifically gardening, green exercise and nature-based therapy, are effective for improving mental health outcomes in adults, including those with pre-existing mental health problems.

Rare gene knockouts in adult humans: On average, most people's genomes contain approximately 100 completely nonfunctional genes. These loss-of-function (LOF) mutations tend to be rare and/or occur only as a single copy within individuals. Narasimhan et al. investigated LOF in a Pakistani population with high levels of consanguinity. Examining LOF alleles that were identical by descent, they found, as expected, an absence of homozygote LOF for certain protein-coding genes. However, they also identified many homozygote LOF alleles with no apparent deleterious phenotype, including some that were expected to confer genetic disease. Indeed, one family had lost the recombination-associated gene PRDM9 . Science , this issue p. 474

Background: Developmental periods in early life may be particularly vulnerable to impacts of environmental exposures. Human research on this topic has generally focused on single exposure–health effect relationships. The “exposome” concept encompasses the totality of exposures from conception onward, complementing the genome. Objectives: The Human Early-Life Exposome (HELIX) project is a new collaborative research project that aims to implement novel exposure assessment and biomarker methods to characterize early-life exposure to multiple environmental factors and associate these with omics biomarkers and child health outcomes, thus characterizing the “early-life exposome.” Here we describe the general design of the project. Methods: In six existing birth cohort studies in Europe, HELIX will estimate prenatal and postnatal exposure to a broad range of chemical and physical exposures. Exposure models will be developed for the full cohorts totaling 32,000 mother–child pairs, and biomarkers will be measured in a subset of 1,200 mother–child pairs. Nested repeat-sampling panel studies (n = 150) will collect data on biomarker variability, use smartphones to assess mobility and physical activity, and perform personal exposure monitoring. Omics techniques will determine molecular profiles (metabolome, proteome, transcriptome, epigenome) associated with exposures. Statistical methods for multiple exposures will provide exposure–response estimates for fetal and child growth, obesity, neurodevelopment, and respiratory outcomes. A health impact assessment exercise will evaluate risks and benefits of combined exposures. Conclusions: HELIX is one of the first attempts to describe the early-life exposome of European populations and unravel its relation to omics markers and health in childhood. As proof of concept, it will form an important first step toward the life-course exposome. Citation: Vrijheid M, Slama R, Robinson O, Chatzi L, Coen M, van den Hazel P, Thomsen C, Wright J, Athersuch TJ, Avellana N, Basagaña X, Brochot C, Bucchini L, Bustamante M, Carracedo A, Casas M, Estivill X, Fairley L, van Gent D, Gonzalez JR, Granum B, Gražulevičienė R, Gutzkow KB, Julvez J, Keun HC, Kogevinas M, McEachan RR, Meltzer HM, Sabidó E, Schwarze PE, Siroux V, Sunyer J, Want EJ, Zeman F, Nieuwenhuijsen MJ. 2014. The Human Early-Life Exposome (HELIX): project rationale and design. Environ Health Perspect 122:535–544; http://dx.doi.org/10.1289/ehp.1307204

The authors explore the role of affective attitudes in predicting 14 health-promoting or health-risk behaviors. Participants (n = 390) completed questionnaire measures of affective and cognitive attitude and, 1 month later, reported their intentions and behavior. The outcome measures in this study were the Time 2 self-report measures of intention and behavior. A series of hierarchical regression analyses revealed that affective attitude was a significantly more powerful predictor of behavior than cognitive attitude for 9 behaviors. Also, affective attitude had a direct effect on behavior that was not fully mediated by intention for 9 behaviors. In a final series of regressions, higher divergence between affective and cognitive attitudes was shown to strengthen the relationship between affective attitudes and behavior for illegal drug use, binge drinking, and smoking. The findings underscore the importance of affect in the performance of health-related behaviors and suggest that interventions could usefully target the affective consequences of engaging in these behaviors. The theoretical and practical implications of these findings are discussed.