Jian Li

Dr. Jian Li

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Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Jian LiJian Li
Jian Li
JSJohannes Siegrist
Johannes Siegrist
In order to update and improve available evidence on associations of physical activity (PA) with cardiovascular disease (CVD) by applying meta-analytic random effects modeling to data from prospective cohort studies, using high quality criteria of study selection, we searched the PubMed database from January 1980 to December 2010 for prospective cohort studies of PA and incident CVD, distinguishing occupational PA and leisure time PA, coronary heart disease (CHD) and stroke, respectively. Inclusion criteria were peer-reviewed English papers with original data, studies with large sample size (n ≥ 1,000) and substantial follow-up (≥5 years), available data on major confounders and on estimates of relative risk (RR) or hazard ratio (HR), with 95% confidence intervals (CI). We included 21 prospective studies in the overall analysis, with a sample size of more than 650,000 adults who were initially free from CVD, and with some 20,000 incident cases documented during follow-up. Among men, RR of overall CVD in the group with the high level of leisure time PA was 0.76 (95% CI 0.70–0.82, p < 0.001), compared to the reference group with low leisure time PA, with obvious dose-response relationship. A similar effect was observed among women (RR = 0.73, 95% CI 0.68–0.78, p < 0.001). A strong protective effect of occupational PA was observed for moderate level in both men (RR = 0.89, 95% CI 0.82–0.97, p = 0.008) and women (RR = 0.83, 95% CI 0.67–1.03, p = 0.089). No publication bias was observed. Our findings suggest that high level of leisure time PA and moderate level of occupational PA have a beneficial effect on cardiovascular health by reducing the overall risk of incident coronary heart disease and stroke among men and women by 20 to 30 percent and 10 to 20 percent, respectively. This evidence from high quality studies supports efforts of primary and secondary prevention of CVD in economically advanced as well as in rapidly developing countries.

1 September 2021 in Environment International
Verified
Journal Article
Open access
FPFrank Pega
Frank Pega
BNBálint Náfrádi
Bálint Náfrádi
NMNatalie C. Momen
Natalie C. Momen
YUYuka Ujita
Yuka Ujita
KSKai N. Streicher
Kai N. Streicher
TWTracey J. Woodruff
Tracey J. Woodruff
World Health Organization (WHO) and International Labour Organization (ILO) systematic reviews reported sufficient evidence for higher risks of ischemic heart disease and stroke amongst people working long hours (≥55 hours/week), compared with people working standard hours (35–40 hours/week). This article presents WHO/ILO Joint Estimates of global, regional, and national exposure to long working hours, for 194 countries, and the attributable burdens of ischemic heart disease and stroke, for 183 countries, by sex and age, for 2000, 2010, and 2016. We calculated population-attributable fractions from estimates of the population exposed to long working hours and relative risks of exposure on the diseases from the systematic reviews. The exposed population was modelled using data from 2324 cross-sectional surveys and 1742 quarterly survey datasets. Attributable disease burdens were estimated by applying the population-attributable fractions to WHO’s Global Health Estimates of total disease burdens. In 2016, 488 million people (95% uncertainty range: 472–503 million), or 8.9% (8.6–9.1) of the global population, were exposed to working long hours (≥55 hours/week). An estimated 745,194 deaths (705,786–784,601) and 23.3 million disability-adjusted life years (22.2–24.4) from ischemic heart disease and stroke combined were attributable to this exposure. The population-attributable fractions for deaths were 3.7% (3.4–4.0) for ischemic heart disease and 6.9% for stroke (6.4–7.5); for disability-adjusted life years they were 5.3% (4.9–5.6) for ischemic heart disease and 9.3% (8.7–9.9) for stroke. WHO and ILO estimate exposure to long working hours (≥55 hours/week) is common and causes large attributable burdens of ischemic heart disease and stroke. Protecting and promoting occupational and workers’ safety and health requires interventions to reduce hazardous long working hours.

9 January 2023 in Behavioral Sciences
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Journal Article
Open access
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Jian LiJian Li
Jian Li
Eryong XueEryong Xue
Eryong Xue
Student engagement plays a significant role in promoting student learning outcomes in the higher education context. The goal of this meta-analysis was to investigate factors influencing student engagement in higher education institutions in different contexts. The meta-analysis integrated data from 93,188 participants and 148 effects across studies to address this issue. The meta-analysis revealed 14 factors affecting students’ learning participation. The classification was based on internal and external factors, aiming to explore the main factors influencing students’ intention, behavior, and process of learning participation. The external influencing factors with moderate correlations were the teacher-student relationship (R = 0.456, p < 0.001) and positive teacher behavior (R = 0.419, p < 0.001). Additionally, the main external influencing factors were partnership (R = 0.174, p < 0.001), environmental support (R = −0.028), negative teacher behavior (R = −0.064), and negative learning behavior (R = −0145), which were all negatively correlated with learning participation. The results also indicated that factors influencing student engagement can be divided into two categories: promoting factors and hindering factors. The promoting factors include students’ positive emotion, positive learning behavior, positive teacher behavior, the teacher-student relationship and partnership, students’ learning and thinking ability, the support of learning resources, students’ individual and personality characteristics, and teaching factors. The hindering factors include lack of environmental support, negative student behavior, and negative teacher behavior. Further, conceptual and practical implications are discussed in relation to these findings.

JSJohannes Siegrist
Johannes Siegrist
Jian LiJian Li
Jian Li
Mainstream psychological stress theory claims that it is important to include information on people’s ways of coping with work stress when assessing the impact of stressful psychosocial work environments on health. Yet, some widely used respective theoretical models focus exclusively on extrinsic factors. The model of effort-reward imbalance (ERI) differs from them as it explicitly combines information on extrinsic and intrinsic factors in studying workers’ health. As a growing number of studies used the ERI model in recent past, we conducted a systematic review of available evidence, with a special focus on the distinct contribution of its intrinsic component, the coping pattern “over-commitment”, towards explaining health. Moreover, we explore whether the interaction of intrinsic and extrinsic components exceeds the size of effects on health attributable to single components. Results based on 51 reports document an independent explanatory role of “over-commitment” in explaining workers’ health in a majority of studies. However, support in favour of the interaction hypothesis is limited and requires further exploration. In conclusion, the findings of this review support the usefulness of a work stress model that combines extrinsic and intrinsic components in terms of scientific explanation and of designing more comprehensive worksite stress prevention programs.

1 September 2013 in Current Opinion in Cardiology
Verified
Journal Article
Closed access
Jian LiJian Li
Jian Li
ALAdrian Loerbroks
Adrian Loerbroks
PAPeter Angerer
Peter Angerer
Abundant evidence has documented inverse associations of physical activity and the risk of cardiovascular disease (CVD). However, the effects of different types of physical activity (e.g., leisure time and occupational physical activity) are still poorly understood. Drawing on recommended and established guidelines for study selection, we identified and included 23 prospective epidemiological studies published during the last 2 years. These studies included a total of more than 790 000 adults at baseline with some 22 000 incident cases occurring during follow-up. Our findings suggest that moderate and high levels of leisure time physical activity are associated with a moderately reduced risk of CVD. In contrast, moderate and high levels of occupational physical activity showed weak positive associations, that is, a slightly increased risk of CVD. This updated meta-analysis supports the notion of primary prevention of CVD through engagement in leisure time physical activity. The role of occupational physical activity in CVD prevention is questionable.

1 September 2020 in Environment International
Verified
Journal Article
Open access
Jian LiJian Li
Jian Li
FPFrank Pega
Frank Pega
YUYuka Ujita
Yuka Ujita
CBChantal Brisson
Chantal Brisson
ECEls Clays
Els Clays
JSJohannes Siegrist
Johannes Siegrist
The World Health Organization (WHO) and the International Labour Organization (ILO) are developing Joint Estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates), with contributions from a large network of experts. Evidence from mechanistic data suggests that exposure to long working hours may cause ischaemic heart disease (IHD). In this paper, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from IHD that are attributable to exposure to long working hours, for the development of the WHO/ILO Joint Estimates. We aimed to systematically review and meta-analyse estimates of the effect of exposure to long working hours (three categories: 41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on IHD (three outcomes: prevalence, incidence and mortality). We developed and published a protocol, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic databases for potentially relevant records from published and unpublished studies, including MEDLINE, Scopus, Web of Science, CISDOC, PsycINFO, and WHO ICTRP. We also searched grey literature databases, Internet search engines and organizational websites; hand-searched reference lists of previous systematic reviews; and consulted additional experts. We included working-age (≥15 years) workers in the formal and informal economy in any WHO and/or ILO Member State but excluded children (aged < 15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies which contained an estimate of the effect of exposure to long working hours (41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on IHD (prevalence, incidence or mortality). At least two review authors independently screened titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. Missing data were requested from principal study authors. We combined relative risks using random-effect meta-analysis. Two or more review authors assessed the risk of bias, quality of evidence and strength of evidence, using Navigation Guide and GRADE tools and approaches adapted to this project. Thirty-seven studies (26 prospective cohort studies and 11 case-control studies) met the inclusion criteria, comprising a total of 768,751 participants (310,954 females) in 13 countries in three WHO regions (Americas, Europe and Western Pacific). The exposure was measured using self-reports in all studies, and the outcome was assessed with administrative health records (30 studies) or self-reported physician diagnosis (7 studies). The outcome was defined as incident non-fatal IHD event in 19 studies (8 cohort studies, 11 case-control studies), incident fatal IHD event in two studies (both cohort studies), and incident non-fatal or fatal ("mixed") event in 16 studies (all cohort studies). Because we judged cohort studies to have a relatively lower risk of bias, we prioritized evidence from these studies and treated evidence from case-control studies as supporting evidence. For the bodies of evidence for both outcomes with any eligible studies (i.e. IHD incidence and mortality), we did not have serious concerns for risk of bias (at least for the cohort studies). No eligible study was found on the effect of long working hours on IHD prevalence. Compared with working 35-40 h/week, we are uncertain about the effect on acquiring (or incidence of) IHD of working 41-48 h/week (relative risk (RR) 0.98, 95% confidence interval (CI) 0.91 to 1.07, 20 studies, 312,209 participants, I2 0%, low quality of evidence) and 49-54 h/week (RR 1.05, 95% CI 0.94 to 1.17, 18 studies, 308,405 participants, I2 0%, low quality of evidence). Compared with working 35-40 h/week, working ≥55 h/week may have led to a moderately, clinically meaningful increase in the risk of acquiring IHD, when followed up between one year and 20 years (RR 1.13, 95% CI 1.02 to 1.26, 22 studies, 339,680 participants, I2 5%, moderate quality of evidence). Compared with working 35-40 h/week, we are very uncertain about the effect on dying (mortality) from IHD of working 41-48 h/week (RR 0.99, 95% CI 0.88 to 1.12, 13 studies, 288,278 participants, I2 8%, low quality of evidence) and 49-54 h/week (RR 1.01, 95% CI 0.82 to 1.25, 11 studies, 284,474 participants, I2 13%, low quality of evidence). Compared with working 35-40 h/week, working ≥55 h/week may have led to a moderate, clinically meaningful increase in the risk of dying from IHD when followed up between eight and 30 years (RR 1.17, 95% CI 1.05 to 1.31, 16 studies, 726,803 participants, I2 0%, moderate quality of evidence). Subgroup analyses found no evidence for differences by WHO region and sex, but RRs were higher among persons with lower SES. Sensitivity analyses found no differences by outcome definition (exclusively non-fatal or fatal versus "mixed"), outcome measurement (health records versus self-reports) and risk of bias ("high"/"probably high" ratings in any domain versus "low"/"probably low" in all domains). We judged the existing bodies of evidence for human evidence as "inadequate evidence for harmfulness" for the exposure categories 41-48 and 49-54 h/week for IHD prevalence, incidence and mortality, and for the exposure category ≥55 h/week for IHD prevalence. Evidence on exposure to working ≥55 h/week was judged as "sufficient evidence of harmfulness" for IHD incidence and mortality. Producing estimates for the burden of IHD attributable to exposure to working ≥55 h/week appears evidence-based, and the pooled effect estimates presented in this systematic review could be used as input data for the WHO/ILO Joint Estimates.