The Xpert® MTB/RIF cycle threshold value predicts M. tuberculosis transmission to close contacts in a Brazilian prospective multicenter cohort.

BACKGROUND: The Xpert® MTB/RIF rapid molecular test provides a quantitative measure of Mycobacterium tuberculosis (Mtb) DNA in the form of cycle threshold (Ct) values. This information can be translated into mycobacterial load and used as a potential risk measure of bacterial spread for tuberculosis cases, which can impact infection control. However, the role of Ct values in assessing Mtb transmission to close contacts has not yet been demonstrated. METHODS: A prospective study was performed to investigate the association between Xpert® MTB/RIF Ct values and Mtb transmission to close contacts of patients with culture-confirmed pulmonary TB in a multi-center Brazilian cohort. We evaluated clinical and laboratory data, such as age, sex, race, smoking habits, drug use, alcohol use, chest radiograph, Xpert® MTB/RIF results among pulmonary tuberculosis cases, and QuantiFERON(QFT)-Plus results at baseline and after six months for close contacts who had a negative result at baseline. RESULTS: A total of 1,055 close contacts of 382 pulmonary tuberculosis cases were included in the study. The median Ct values from pulmonary tuberculosis cases of QFT-Plus positive (at baseline or six months) close contacts were lower compared with those who were QFT-Plus negative. An adjusted logistic regression demonstrated that reduced Ct values from the index cases were independently associated with QFT-Plus conversion from negative to positive (OR: 1.61, 95% CI: 1.12-2.32) after adjusting for clinical characteristics. CONCLUSION: Close contacts of pulmonary TB index cases exhibiting low Xpert MTB/RIF Ct values displayed higher rates of TB infection, reflecting Mtb transmission.

Association between friendship quality and subjective wellbeing in adolescents: a cross-sectional observational study.

BACKGROUND: Friendships play a vital role in the social lives of teenagers, and friendship quality can substantially impact the adolescents' overall health and wellbeing. This study aimed to investigate the association between friendship quality and subjective wellbeing in Northern Irish adolescents. METHODS: In this cross-sectional observational study, we used data from the second wave of the Wellbeing in Schools Survey, conducted in Northern Ireland from April 2 to May 31, 2018. This survey used a clustering sampling method and included students aged 15-19 years. The survey was approved by the School of Social Sciences, Education and Social Work's Research Ethics Committee, with pupil opt-in and parental opt-out consents. Participants from the survey's initial wave in 2016 were considered eligible. Data on friendship quality and classroom friendships were gathered. Subjective wellbeing was assessed using the 7-item Short Warwick-Edinburgh Mental Wellbeing Scale. Metrics for psychological wellbeing (6 items), mood (7 items), and friendship quality (6 items) were taken from the KIDSCREEN-52 questionnaire. All items were rated on a 1-5 point Likert scale. We examined the association between friendship network quality and subjective wellbeing outcomes through social network analysis and network autocorrelation modelling. FINDINGS: Of 1542 students invited, 1189 (77%) from 83 schools responded to the friendship network queries. Slightly more than half of these participants were female (609 [51%] girls and 580 [49%] boys), and the median age was 16 years (range 14-19, IQR 16-16). The median overall friendship score stood at 20 (IQR 18-26, with possible scores ranging from 6 to 30). Adjusted network autocorrelation models indicated that higher friendship quality scores were significantly associated with improved psychological wellbeing (ß=0·3448, p<0·0001), subjective wellbeing (ß=0·3075, p<0·0001), and a reduction in negative mood (ß=-0·1934, p<0·0001). INTERPRETATION: The study found that friendship quality had a significant association with mood, psychological wellbeing, and subjective wellbeing in adolescents. The results emphasise the value of fostering positive social relationships among adolescents, with a particular focus on the quality of their friendships. Next stages of this research include longitudinal analysis to test these associations more robustly. FUNDING: Taibah University.

What is the impact of national public expenditure and its allocation on neonatal and child mortality? A machine learning analysis.

BACKGROUND: Understanding the impact of national public expenditure and its allocation on child mortality may help governments move towards target 3.2 proposed in the 2030 Agenda. The objective of this study was to estimate the impacts of governmental expenditures, total, on health, and on other sectors, on neonatal mortality and mortality of children aged between 28 days and five years. METHODS: This study has an ecological design with a population of 147 countries, with data between 2012 and 2019. Two steps were used: first, the Generalized Propensity Score of public spending was calculated; afterward, the Generalized Propensity Score was used to estimate the expenditures' association with mortality rates. The primary outcomes were neonatal mortality rates (NeoRt) and mortality rates in children between 28 days and 5 years (NeoU5Rt). RESULTS: The 1% variation in Int$ Purchasing Power Parity (Int$ PPP) per capita in total public expenditures, expenditure in health, and in other sectors were associated with a variation of -0.635 (95% CI -1.176, -0.095), -2.17 (95% CI -3.051, -1.289) -0.632 (95% CI -1.169, -0.095) in NeoRt, respectively The same variation in public expenditures in sectors other than health, was associates with a variation of -1.772 (95% CI -6.219, -1.459) on NeoU5Rt. The results regarding the impact of total and health public spending on NeoU5Rt were not consistent. CONCLUSION: Public investments impact mortality in children under 5 years of age. Likely, the allocation of expenditures between the health sector and the other social sectors will have different impacts on mortality between the NeoRt and the NeoU5Rt.

Non-occupational physical activity and risk of cardiovascular disease, cancer and mortality outcomes: a dose-response meta-analysis of large prospective studies.

OBJECTIVE: To estimate the dose-response associations between non-occupational physical activity and several chronic disease and mortality outcomes in the general adult population. DESIGN: Systematic review and cohort-level dose-response meta-analysis. DATA SOURCES: PubMed, Scopus, Web of Science and reference lists of published studies. ELIGIBILITY CRITERIA: Prospective cohort studies with (1) general population samples >10 000 adults, (2) ≥3 physical activity categories, and (3) risk measures and CIs for all-cause mortality or incident total cardiovascular disease, coronary heart disease, stroke, heart failure, total cancer and site-specific cancers (head and neck, myeloid leukaemia, myeloma, gastric cardia, lung, liver, endometrium, colon, breast, bladder, rectum, oesophagus, prostate, kidney). RESULTS: 196 articles were included, covering 94 cohorts with >30 million participants. The evidence base was largest for all-cause mortality (50 separate results; 163 415 543 person-years, 811 616 events), and incidence of cardiovascular disease (37 results; 28 884 209 person-years, 74 757 events) and cancer (31 results; 35 500 867 person-years, 185 870 events). In general, higher activity levels were associated with lower risk of all outcomes. Differences in risk were greater between 0 and 8.75 marginal metabolic equivalent of task-hours per week (mMET-hours/week) (equivalent to the recommended 150 min/week of moderate-to-vigorous aerobic physical activity), with smaller marginal differences in risk above this level to 17.5 mMET-hours/week, beyond which additional differences were small and uncertain. Associations were stronger for all-cause (relative risk (RR) at 8.75 mMET-hours/week: 0.69, 95% CI 0.65 to 0.73) and cardiovascular disease (RR at 8.75 mMET-hours/week: 0.71, 95% CI 0.66 to 0.77) mortality than for cancer mortality (RR at 8.75 mMET-hours/week: 0.85, 95% CI 0.81 to 0.89). If all insufficiently active individuals had achieved 8.75 mMET-hours/week, 15.7% (95% CI 13.1 to 18.2) of all premature deaths would have been averted. CONCLUSIONS: Inverse non-linear dose-response associations suggest substantial protection against a range of chronic disease outcomes from small increases in non-occupational physical activity in inactive adults. PROSPERO registration number CRD42018095481.

Identification of wild rodents as intermediate hosts for Hydatigera taeniaeformis in Peru.

Hydatigera taeniaeformis is a cestode that uses felines and rodents as definitive and intermediate hosts, respectively. Its larval stage, or metacestode, infects a wide variety of rodent species and develops in the liver parenchyma into a cyst. The aim of this study was to evaluate the occurrence of H. taeniaeformis metacestode in various species of wild rodents from Peru. For this, the livers of 356 rodents were macroscopically examined for any parasitic form compatible with metacestodes. Metacestodes were identified by measuring characteristic morphological parameters, and the diagnosis was confirmed by molecular analysis of a fragment of the cytochrome c oxidase subunit 1 gene (cox1). Five rodents: two small-eared pygmy rice rats (Oligoryzomys microtis), two white-naped squirrels (Simosciurus nebouxii), and one pygmy rice rat (Oligoryzomys sp.) were infected with H. taeniaeformis metacestodes. The cox1 sequences from our metacestodes showed up to 100% identity with previous H. taeniaeformis sequences from the GenBank. These results demonstrated the occurrence of H. taeniaeformis in new intermediate hosts, as well as the first molecular contribution for H. taeniaeformis from Peru.

The internal ribosome entry site of the Dengue virus mRNA is active when cap-dependent translation initiation is inhibited.

Dengue virus (DENV) is an enveloped, positive-sense, single-stranded RNA virus belonging to the Flaviviridae family. Translation initiation of the DENV mRNA can occur following a cap-dependent or a cap-independent mechanism. Two non-mutually exclusive cap-independent mechanisms of translation initiation have been described for the DENV mRNA. The first corresponds to a 5'end-dependent internal ribosome entry site (IRES)-independent mechanism, while the second relies on IRES-dependent initiation. In this report, we study the recently discovered DENV IRES. Results show that the DENV IRES is functional in the rabbit reticulocyte (RRL) in vitro translation system. In accordance, the activity of DENV IRES was resistant to the cleavage of eIF4G by the Foot-and-mouth disease virus leader protease in RRL. In cells, the DENV IRES exhibited only a marginal activity under standard culture conditions. The DENV IRES showed weak activity in HEK 293T cells; however, the DENV IRES activity was significantly enhanced in HEK 293T cells expressing the Human rhinovirus 2A protease. These findings suggest that the DENV IRES enables viral protein synthesis under conditions that suppress canonical translation initiation.IMPORTANCE Dengue virus (DENV), the etiological agent of Dengue, a febrile and hemorrhagic disease, infects millions of people per year in tropical and subtropical countries. When infecting cells, DENV induces stress conditions known to inhibit canonical protein synthesis. Under these conditions, DENV mRNA thrives using non-canonical modes of translation initiation. In this study, we characterize the mechanism dependent upon an internal ribosome entry site (IRES). Herein, we describe the activity of the DENV IRES in vitro and cells. We show that in cells, DENV IRES enables the viral mRNA to translate under conditions that suppress canonical translation initiation.

Post-translational modifications of hnRNP A1 differentially modulate retroviral IRES-mediated translation initiation.

The full-length mRNAs of the human immunodeficiency virus type-1 (HIV-1), the human T-cell lymphotropic virus type-1 (HTLV-1), and the mouse mammary tumor virus (MMTV) harbor IRESs. The activity of the retroviral-IRESs requires IRES-transacting factors (ITAFs), being hnRNP A1, a known ITAF for the HIV-1 IRES. In this study, we show that hnRNP A1 is also an ITAF for the HTLV-1 and MMTV IRESs. The MMTV IRES proved to be more responsive to hnRNP A1 than either the HTLV-1 or the HIV-1 IRESs. The impact of post-translational modifications of hnRNP A1 on HIV-1, HTLV-1 and MMTV IRES activity was also assessed. Results show that the HIV-1 and HTLV-1 IRESs were equally responsive to hnRNP A1 and its phosphorylation mutants S4A/S6A, S4D/S6D and S199A/D. However, the S4D/S6D mutant stimulated the activity from the MMTV-IRES to levels significantly higher than the wild type hnRNP A1. PRMT5-induced symmetrical di-methylation of arginine residues of hnRNP A1 enabled the ITAF to stimulate the HIV-1 and HTLV-1 IRESs while reducing the stimulatory ability of the ITAF over the MMTV IRES. We conclude that retroviral IRES activity is not only dependent on the recruited ITAFs but also relies on how these proteins are modified at the post-translational level.

Association between friendship quality and subjective wellbeing among adolescents: a systematic review.

BACKGROUND: Social integration with friends has an important role in shaping adolescents' behavior and determining their wellbeing. Friendship features such as companionship, trust, closeness, intimacy, and conflicts all form the concept of friendship quality. The quality of friendships can either enhance or impede mental development during adolescence. Therefore, this systematic review was conducted to understand the association between friendship quality and adolescents' mental wellbeing. METHODS: In November 2020 and later in August 2022, the search for evidence was conducted on five databases (Medline, Embase, ProQuest, Scopus, and PsycINFO). Only peer-reviewed quantitative studies published from January 2000 to August 2022 that investigated friendship quality as their exposure variable in relation to six constructs of subjective wellbeing (mood, loneliness, life satisfaction, happiness, self-esteem, and subjective wellbeing) were included. After screening for eligibility, two reviewers independently extracted the data based on population characteristics, study design, exposure and outcome variables, outcome measures used, and results. Risk of bias assessment was performed utilizing the NIH Quality Assessment Tool. Narrative evidence synthesis was performed based on the constructs of subjective wellbeing. RESULTS: Forty-three articles out of 21,585 records were included in the review. The relationship between friendship quality and depression has been investigated extensively in the literature and negative (beneficial) associations were found in eighteen studies out of twenty-three. Poor peer relationship was associated with loneliness in nine studies out of ten. All seven studies on life satisfaction and quality of peer connection found a positive association. In five studies, better peer relationship was found to be associated with happiness. A positive association between friendship quality and self-esteem was observed in five out of six applicable studies. Friendship quality was found to be positively associated with subjective well-being in all of five included studies. CONCLUSIONS: Although majority of the included studies were cross-sectional in nature, this review demonstrates the paramount value of promoting healthy friendship to adolescents' subjective wellbeing constructs. Interventions that aim to promote subjective wellbeing among adolescents should consider the development and maintenance of healthy friendships. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020219312.

Barriers and facilitators of domain-specific physical activity: a systematic review of reviews.

BACKGROUND: Knowing what facilitates and hinders physical activity behaviour across domains (leisure, travel, work or education, and household) is central for the development of actions for more active lifestyles. Thus, the aim of this systematic review of reviews was to summarize the evidence on barriers and facilitators of domain-specific physical activity. METHODS: We included systematic reviews with or without meta-analysis that investigated the association between modifiable barriers and facilitators and levels of domain-specific physical activity. Reviews published until September 2020 were retrieved from PubMed, ISI Web of Science, Scopus, Regional Library of Medicine (BIREME), and PsycNET, and from the reference list of selected articles. Each review was screened by two independent reviewers for eligibility. Data extracted from selected papers included methodological aspects (number of primary studies, study designs, and age groups); physical activity domains and barriers and facilitators investigated; and direction of association. For each pair of barrier/facilitator and domain-specific physical activity, we recorded the number of positive, negative, and null associations reported across reviews. Quality assessment of each systematic review was performed using the AMSTAR-2 tool. RESULTS: Forty-four systematic reviews were selected. The evidence base was largest for leisure-time followed by travel-related physical activity. A very small number of reviews included physical activity in work, educational and domestic settings. Across all physical activity domains, factors related to the built environment were more abundant in the reviews than intra and interpersonal factors. Very consistent positive associations were observed between a range of intrapersonal factors and leisure-time physical activity, as well as moderately consistent evidence of positive association for general social support and support from family members. Evidence of moderate consistency was found for the positive association between transport-related physical activity and positive beliefs about consequences, walkability, and existence of facilities that support active travel. Evidence on barriers and facilitators for physical activity at work, educational, and domestic settings was limited in volume and consistency. CONCLUSIONS: Efforts and resources are required to diversify and strength the evidence base on barriers and facilitators of domain-specific physical activity, as it is still limited and biased towards the leisure domain and built environment factors. TRIAL REGISTRATION: PROSPERO CRD42020209710.

Systems science for developing policy to improve physical activity, the Caribbean.

The World Health Organization (WHO) Global Action Plan on Physical Activity recommends adopting a systems approach to implementing and tailoring actions according to local contexts. We held group model-building workshops with key stakeholders in the Caribbean region to develop a causal loop diagram to describe the system driving the increasing physical inactivity in the region and envision the most effective ways of intervening in that system to encourage and promote physical activity. We used the causal loop diagram to inform how the WHO Global Action Plan on Physical Activity might be adapted to a local context. Although the WHO recommendations aligned well with our causal loop diagram, the diagram also illustrates the importance of local context in determining how interventions should be coordinated and implemented. Some interventions included creating safe physical activity spaces for both sexes, tackling negative attitudes to physical activity in certain contexts, including in schools and workplaces, and improving infrastructure for active transport. The causal loop diagram may also help understand how policies may be undermined or supported by key actors or where policies should be coordinated. We demonstrate how, in a region with a high level of physical inactivity and low resources, applying systems thinking with relevant stakeholders can help the targeted adaptation of global recommendations to local contexts.

Le Plan d'action mondial pour l'activité physique élaboré par l'Organisation mondiale de la Santé (OMS) recommande d'adopter une approche systémique pour la création et le déploiement d'actions adaptées aux contextes locaux. Nous avons organisé des ateliers de construction de modèles regroupant divers acteurs clés de la région Caraïbes. Objectif: développer un diagramme de boucles causales afin d'identifier le système à l'origine de la sédentarité croissante dans cette région, mais aussi de concevoir les moyens les plus efficaces pour s'immiscer dans ce système en vue d'encourager et de promouvoir l'exercice physique. Nous avons employé le diagramme de boucles causales pour définir comment le Plan d'action mondial pour l'activité physique de l'OMS peut être adapté au contexte local. Bien que les recommandations de l'OMS se rapprochent considérablement de notre diagramme, ce dernier illustre aussi l'importance du contexte local dans la manière dont les interventions sont censées être coordonnées et mises en œuvre. Certaines de ces interventions prévoyaient d'ouvrir des espaces sécurisés dédiés à la pratique sportive pour les deux sexes, de lutter contre les attitudes négatives vis-à-vis de l'activité physique dans des situations spécifiques, notamment à l'école et au travail, et de rendre les infrastructures compatibles avec les modes de transport actifs. Le diagramme de boucles causales permet en outre de mieux comprendre comment les acteurs clés peuvent soutenir ou au contraire discréditer les politiques en la matière, et de voir où ces politiques ont besoin de coordination. Nous démontrons comment, dans une région marquée par un taux de sédentarité élevé et de faibles ressources, l'adoption d'une approche systémique impliquant les principaux intervenants peut contribuer à ajuster avec précision des recommandations mondiales à des contextes locaux.

El Plan de acción mundial sobre actividad física de la Organización Mundial de la Salud (OMS) recomienda adoptar un enfoque sistémico para implementar y adaptar las acciones según los contextos locales. Celebramos talleres de construcción de modelos de grupo con las principales partes interesadas en la región del Caribe para desarrollar un diagrama de circuito causal para describir el sistema que impulsa la creciente inactividad física en la región y prever las formas más eficaces de intervenir en ese sistema para fomentar y promover la actividad física. Utilizamos el diagrama de circuito causal para informar sobre cómo se podría adaptar el Plan de acción mundial sobre actividad física de la OMS a un contexto local. Aunque las recomendaciones de la OMS se ajustaban bien a nuestro diagrama, este también ilustra la importancia del contexto local a la hora de determinar cómo deben coordinarse y aplicarse las intervenciones. Algunas intervenciones incluyen la creación de espacios seguros para la actividad física para ambos sexos, la lucha contra las actitudes negativas hacia la actividad física en determinados contextos, incluidos los colegios y los lugares de trabajo, y la mejora de las infraestructuras para el transporte activo. El diagrama de circuito causal también puede ayudar a entender cómo las políticas pueden ser socavadas o apoyadas por actores clave o dónde deben coordinarse las políticas. Demostramos cómo, en una región con un alto nivel de inactividad física y pocos recursos, la aplicación del pensamiento sistémico con las partes interesadas pertinentes puede ayudar a la adaptación específica de las recomendaciones globales a los contextos locales.

Study protocol: health survey of Sao Paulo: ISA-Physical Activity and Environment.

BACKGROUND: Many studies have investigated the association between the built environment and physical activity behavior in urban settings. However, most of the studies conducted in low- and middle-income countries were cross-sectional, which are limited to identify behavioral determinants. We propose a prospective cohort study to verify the relationship between built environment features and leisure-time and transport-related physical activity in adults from Sao Paulo city, Brazil. METHODS: Prospective multilevel cohort, denominated "ISA-Physical Activity and Environment". It will build on the Health Survey of Sao Paulo in 2015 ("Inquérito de Saúde de São Paulo (ISA)" in Portuguese). The Health Survey of Sao Paulo, originally designed as a cross-sectional survey, had a multi-stage sample, covering 150 census tracts distributed in five health administrative areas. Data collection was performed by face-to-face interviews until December 2015 and the sample comprised 4043 individuals aged 12 years or more. The ISA-Physical Activity and Environment study will reassess people who are aged 18 years or more in 2020, including telephone and household interviews. The primary outcome will be leisure-time and transport-related physical activity, assessed through the International Physical Activity Questionnaire long version. Exposure variables will be built environment features in the areas participants live and work in the follow-up. Data analysis will include multivariate multilevel linear and logistic models. We will also conduct cost-effectiveness analysis and develop agent-based models to help inform decision-makers. The study will be conducted by an interdisciplinary research team specialized in physical activity epidemiology, nutritional epidemiology, georeferencing applied to health, statistics, agent-based modeling, public health policy, and health economics. DISCUSSION: There are few longitudinal studies on the relationship between the built environment and physical activity behavior in low- and middle-income countries. We believe that the ISA-Physical Activity and Environment study will contribute with important results for the progress of the knowledge in this field and for the implementation of policies that promote leisure-time physical activity and active travel in Sao Paulo and similar cities across the world.

Mix of destinations and sedentary behavior among Brazilian adults: a cross-sectional study.

BACKGROUND: Sedentary behavior is influenced by contextual, social, and individual factors, including the built environment. However, associations between the built environment and sitting time have not been extensively investigated in countries with economies in transition such as Brazil. The objective of this study is to examine the relationship between sitting-time and access to a mix of destinations for adults from Sao Paulo city, Brazil. METHODS: This study uses data from the Health Survey of Sao Paulo. Sedentary behavior was assessed by a questionnaire using two questions: total sitting time in minutes on a usual weekday; and on a usual weekend day. The mix of destinations was measured by summing the number of facilities (comprising bus stops, train/subway stations, parks, squares, public recreation centres, bike paths, primary health care units, supermarkets, food stores, bakeries, and coffee-shops) within 500 m of each participant's residence. Minutes of sitting time in a typical weekday and weekend day were the outcomes and the mix of destinations score in 500 m buffers was the exposure variable. Associations between the mix of destinations and sitting time were examined using multilevel linear regression: these models accounted for clustering within census tracts and households and adjusted for environmental, sociodemographic, and health-related factors. RESULTS: After adjustment for covariates, the mix of destinations was inversely associated with minutes of sitting time on a weekday (ß=- 8.8, p=0.001) and weekend day (ß=- 6.1, p=0.022). People who lived in areas with a greater mix of destinations had shorter average sitting times. CONCLUSION: Greater mix of destinations within 500 m of peoples' residences was inversely associated with sitting time on a typical weekday and weekend day. In Latin American cities like Sao Paulo built environments more favorable for walking may contribute to reducing sedentary behavior and prevent associated chronic disease.

Polymorphism of lncRNAs in breast cancer: Meta-analysis shows no association with susceptibility.

BACKGROUND: Long non-coding RNAs (lncRNAs) have been the target of considerable attention for their roles in many biological processes. Only a small portion of lncRNAs are functionally characterized, and several approaches have been proposed for investigating the roles of these molecules, including how polymorphisms in lncRNA genomic sites may interfere with their function. Allele frequency variation in single nucleotide polymorphisms (SNPs), for example, has been associated with several diseases, including breast cancer (BC), the most common type of cancer in women. METHODS: In the present study, we performed a systematic review of lncRNA SNPs associated with BC and a meta-analysis of some lncRNA SNPs. We found 31 SNPs mapped in 12 lncRNAs associated with BC in 28 case-control studies. RESULTS: Our meta-analysis showed an insignificant difference between the SNPs rs217727, rs3741219, rs2107425 and rs2839698 on H19, as well as rs920778, rs1899663, rs12826786 and rs4759314 on HOTAIR, and BC susceptibility. CONCLUSIONS: The present analysis recognized the importance of extensive association studies, including different populations, and further evaluation of potential functional effects caused by lncRNA SNPs. Nevertheless, genetic variants such as SNPs in lncRNAs may play many other essential roles, although this field is still under explored.

Advancing the global physical activity agenda: recommendations for future research by the 2020 WHO physical activity and sedentary behavior guidelines development group.

BACKGROUND: In July, 2019, the World Health Organization (WHO) commenced work to update the 2010 Global Recommendations on Physical Activity for Health and established a Guideline Development Group (GDG) comprising expert public health scientists and practitioners to inform the drafting of the 2020 Guidelines on Physical Activity and Sedentary Behavior. The overall task of the GDG was to review the scientific evidence and provide expert advice to the WHO on the amount of physical activity and sedentary behavior associated with optimal health in children and adolescents, adults, older adults (> 64 years), and also specifically in pregnant and postpartum women and people living with chronic conditions or disabilities. METHODS: The GDG reviewed the available evidence specific to each sub-population using systematic protocols and in doing so, identified a number of gaps in the existing literature. These proposed research gaps were discussed and verified by expert consensus among the entire GDG. RESULTS: Evidence gaps across population sub-groups included a lack of information on: 1) the precise shape of the dose-response curve between physical activity and/or sedentary behavior and several of the health outcomes studied; 2) the health benefits of light-intensity physical activity and of breaking up sedentary time with light-intensity activity; 3) differences in the health effects of different types and domains of physical activity (leisure-time; occupational; transportation; household; education) and of sedentary behavior (occupational; screen time; television viewing); and 4) the joint association between physical activity and sedentary time with health outcomes across the life course. In addition, we acknowledge the need to conduct more population-based studies in low- and middle-income countries and in people living with disabilities and/or chronic disease, and to identify how various sociodemographic factors (age, sex, race/ethnicity, socioeconomic status) modify the health effects of physical activity, in order to address global health disparities. CONCLUSIONS: Although the 2020 WHO Guidelines for Physical Activity and Sedentary Behavior were informed by the most up-to-date research on the health effects of physical activity and sedentary time, there is still substantial work to be done in advancing the global physical activity agenda.

A systematic review of empirical and simulation studies evaluating the health impact of transportation interventions.

Urban transportation is an important determinant of health and environmental outcomes, and therefore essential to achieving the United Nation's Sustainable Development Goals. To better understand the health impacts of transportation initiatives, we conducted a systematic review of longitudinal health evaluations involving: a) bus rapid transit (BRT); b) bicycle lanes; c) Open Streets programs; and d) aerial trams/cable cars. We also synthesized systems-based simulation studies of the health-related consequences of walking, bicycling, aerial tram, bus and BRT use. Two reviewers screened 3302 unique titles and abstracts identified through a systematic search of MEDLINE (Ovid), Scopus, TRID and LILACS databases. We included 39 studies: 29 longitudinal evaluations and 10 simulation studies. Five studies focused on low- and middle-income contexts. Of the 29 evaluation studies, 19 focused on single component bicycle lane interventions; the rest evaluated multi-component interventions involving: bicycle lanes (n = 5), aerial trams (n = 1), and combined bicycle lane/BRT systems (n = 4). Bicycle lanes and BRT systems appeared effective at increasing bicycle and BRT mode share, active transport duration, and number of trips using these modes. Of the 10 simulation studies, there were 9 agent-based models and one system dynamics model. Five studies focused on bus/BRT expansions and incentives, three on interventions for active travel, and the rest investigated combinations of public transport and active travel policies. Synergistic effects were observed when multiple policies were implemented, with several studies showing that sizable interventions are required to significantly shift travel mode choices. Our review indicates that bicycle lanes and BRT systems represent promising initiatives for promoting population health. There is also evidence to suggest that synergistic effects might be achieved through the combined implementation of multiple transportation policies. However, more rigorous evaluation and simulation studies focusing on low- and middle-income countries, aerial trams and Open Streets programs, and a more diverse set of health and health equity outcomes is required.

Levels of domain-specific physical activity at work, in the household, for travel and for leisure among 327 789 adults from 104 countries.

OBJECTIVE: To compare the country-level absolute and relative contributions of physical activity at work and in the household, for travel, and during leisure-time to total moderate-to-vigorous physical activity (MVPA). METHODS: We used data collected between 2002 and 2019 from 327 789 participants across 104 countries and territories (n=24 low, n=34 lower-middle, n=30 upper-middle, n=16 high-income) from all six World Health Organization (WHO) regions. We calculated mean min/week of work/household, travel and leisure MVPA and compared their relative contributions to total MVPA using Global Physical Activity Questionnaire data. We compared patterns by country, sex and age group (25-44 and 45-64 years). RESULTS: Mean MVPA in work/household, travel and leisure domains across the 104 countries was 950 (IQR 618-1198), 327 (190-405) and 104 (51-131) min/week, respectively. Corresponding relative contributions to total MVPA were 52% (IQR 44%-63%), 36% (25%-45%) and 12% (4%-15%), respectively. Work/household was the highest contributor in 80 countries; travel in 23; leisure in just one. In both absolute and relative terms, low-income countries tended to show higher work/household (1233 min/week, 57%) and lower leisure MVPA levels (72 min/week, 4%). Travel MVPA duration was higher in low-income countries but there was no obvious pattern in the relative contributions. Women tended to have relatively less work/household and more travel MVPA; age groups were generally similar. CONCLUSION: In the largest domain-specific physical activity study to date, we found considerable country-level variation in how MVPA is accumulated. Such information is essential to inform national and global policy and future investments to provide opportunities to be active, accounting for country context.

World Health Organization 2020 guidelines on physical activity and sedentary behaviour.

OBJECTIVES: To describe new WHO 2020 guidelines on physical activity and sedentary behaviour. METHODS: The guidelines were developed in accordance with WHO protocols. An expert Guideline Development Group reviewed evidence to assess associations between physical activity and sedentary behaviour for an agreed set of health outcomes and population groups. The assessment used and systematically updated recent relevant systematic reviews; new primary reviews addressed additional health outcomes or subpopulations. RESULTS: The new guidelines address children, adolescents, adults, older adults and include new specific recommendations for pregnant and postpartum women and people living with chronic conditions or disability. All adults should undertake 150-300 min of moderate-intensity, or 75-150 min of vigorous-intensity physical activity, or some equivalent combination of moderate-intensity and vigorous-intensity aerobic physical activity, per week. Among children and adolescents, an average of 60 min/day of moderate-to-vigorous intensity aerobic physical activity across the week provides health benefits. The guidelines recommend regular muscle-strengthening activity for all age groups. Additionally, reducing sedentary behaviours is recommended across all age groups and abilities, although evidence was insufficient to quantify a sedentary behaviour threshold. CONCLUSION: These 2020 WHO guidelines update previous WHO recommendations released in 2010. They reaffirm messages that some physical activity is better than none, that more physical activity is better for optimal health outcomes and provide a new recommendation on reducing sedentary behaviours. These guidelines highlight the importance of regularly undertaking both aerobic and muscle strengthening activities and for the first time, there are specific recommendations for specific populations including for pregnant and postpartum women and people living with chronic conditions or disability. These guidelines should be used to inform national health policies aligned with the WHO Global Action Plan on Physical Activity 2018-2030 and to strengthen surveillance systems that track progress towards national and global targets.

Physical activity and preventable premature deaths from non-communicable diseases in Brazil.

BACKGROUND: Studies on the impact of counterfactual scenarios of physical activity on premature deaths from non-communicable diseases (NCDs) are sparse in the literature. We estimated preventable premature deaths from NCDs (diabetes, ischemic heart disease, stroke, and breast and colon cancers) in Brazil by increasing population-wide physical activity (i) to theoretical minimum risk exposure levels; (ii) reaching the physical activity recommendation; (iii) reducing insufficient physical activity by 10%; and (iv) eliminating the gender differences in physical activity. METHODS: Preventable fractions were estimated using data from a nationally representative survey, relative risks from a meta-analysis and number of premature deaths (30-69 years) from the Brazilian Mortality Information System. RESULTS: Physical activity could potentially avoid up to 16 700 premature deaths from NCDs in Brazil, corresponding to 5.75 and 3.23% of premature deaths from major NCDs and of all-causes, respectively. Other scenarios suggested the following impact on premature deaths: reaching physical activity recommendation (5000 or 1.74% of major NCDs); 10% reduction in insufficient physical activity (500 or 0.17% of major NCDs); eliminating gender differences in physical activity (1000 or 0.33% of major NCDs). CONCLUSIONS: Physical activity may play an important role to reduce premature deaths from NCD in Brazil.

Exploring the emergence and evolution of population patterns of leisure-time physical activity through agent-based modelling.

INTRODUCTION: Most interventions aiming to promote leisure-time physical activity (LTPA) at population level showed small or null effects. Approaching the problem from a systems science perspective may shed light on the reasons for these results. We developed an agent-based model to explore how the interactions between psychological attributes and built and social environments may lead to the emergence and evolution of LTPA patterns among adults. METHODS: The modeling process consisted of four stages: (1) conceptual model development, (2) formulation of the agent-based model, (3) parametrization and calibration, and (4) consistency and sensitivity analyses. The model represents a stylized community containing two types of agents: persons and LTPA sites. Persons interact with each other (proximal network and perceived community) and with the built environment (LTPA sites) over time. Decision-making is based on the person's intention to practice LTPA, conditioned to the perceived environment. Each iteration is equivalent to one week and we assessed a period of 10 years. RESULTS: The model was able to reproduce population temporal trends of intention and LTPA reported in the literature. Sensitivity analyses indicated that population patterns and trends of intention and LTPA were highly influenced by the relationship between a person's behavior in the preceding week and his current intention, the person's access to built and social environment, and the density of LTPA sites. CONCLUSIONS: The proposed agent-based model is suitable to explore the emergence and evolution of LTPA patterns among adults, considering the dynamic interaction between individuals' psychological attributes and the built and social environments in which they live. The model is available at https://doi.org/10.17605/OSF.IO/J2KAS .

Development of a dynamic framework to explain population patterns of leisure-time physical activity through agent-based modeling.

Despite the increasing body of evidences on the factors influencing leisure-time physical activity, our understanding of the mechanisms and interactions that lead to the formation and evolution of population patterns is still limited. Moreover, most frameworks in this field fail to capture dynamic processes. Our aim was to create a dynamic conceptual model depicting the interaction between key psychological attributes of individuals and main aspects of the built and social environments in which they live. This conceptual model will inform and support the development of an agent-based model aimed to explore how population patterns of LTPA in adults may emerge from the dynamic interplay between psychological traits and built and social environments. We integrated existing theories and models as well as available empirical data (both from literature reviews), and expert opinions (based on a systematic expert assessment of an intermediary version of the model). The model explicitly presents intention as the proximal determinant of leisure-time physical activity, a relationship dynamically moderated by the built environment (access, quality, and available activities) - with the strength of the moderation varying as a function of the person's intention- and influenced both by the social environment (proximal network's and community's behavior) and the person's behavior. Our conceptual model is well supported by evidence and experts' opinions and will inform the design of our agent-based model, as well as data collection and analysis of future investigations on population patterns of leisure-time physical activity among adults.