Melatonin and health: an umbrella review of health outcomes and biological mechanisms of action

BackgroundOur aims were to evaluate critically the evidence from systematic reviews as well as narrative reviews of the effects of melatonin (MLT) on health and to identify the potential mechanisms of action involved.MethodsAn umbrella review of the evidence across systematic reviews and narrative reviews of endogenous and exogenous (supplementation) MLT was undertaken. The Oxman checklist for assessing the methodological quality of the included systematic reviews was utilised. The following databases were searched: MEDLINE, EMBASE, Web of Science, CENTRAL, PsycINFO and CINAHL. In addition, reference lists were screened. We included reviews of the effects of MLT on any type of health-related outcome measure.ResultsAltogether, 195 reviews met the inclusion criteria. Most were of low methodological quality (mean -4.5, standard deviation 6.7). Of those, 164 did not pool the data and were synthesised narratively (qualitatively) whereas the remaining 31 used meta-analytic techniques and were synthesised quantitatively. Seven meta-analyses were significant with P values less than 0.001 under the random-effects model. These pertained to sleep latency, pre-operative anxiety, prevention of agitation and risk of breast cancer.ConclusionsThere is an abundance of reviews evaluating the effects of exogenous and endogenous MLT on health. In general, MLT has been shown to be associated with a wide variety of health outcomes in clinically and methodologically heterogeneous populations. Many reviews stressed the need for more high-quality randomised clinical trials to reduce the existing uncertainties

The efficacy of long-term conjugated linoleic acid (CLA) supplementation on body composition in overweight and obese individuals: a systematic review and meta-analysis of randomized clinical trials

INTRODUCTION: Numerous supplements containing conjugated linoleic acid (CLA) are presently being promoted for body weight reduction. The aim of this systematic review is to evaluate the evidence for or against the long-term efficacy of CLA. METHODS: Electronic searches were conducted to identify relevant randomized clinical trials (RCTs). No restrictions in age, time, or language were imposed. Studies had to be at least 6 months in duration. Three reviewers independently determined the eligibility of studies. Two reviewers independently extracted data and assessed the reporting quality of all RCTs. RESULTS: Fifteen RCTs were identified, and seven were included. Four of the included RCTs had serious flaws in the reporting of their methodology. A meta-analysis revealed a statistically significant difference in weight loss favouring CLA over placebo (mean difference: -0.70 kg; 95% confidence interval: -1.09, -0.32). Our meta-analysis also revealed a small significant difference in fat loss favouring CLA over placebo (MD: -1.33 kg; 95% CI: -1.79, -0.86; I (2) = 54%). The magnitude of these effects is small, and the clinical relevance is uncertain. Adverse events included constipation, diarrhea, and soft stools. CONCLUSION: The evidence from RCTs does not convincingly show that CLA intake generates any clinically relevant effects on body composition on the long term

Online digital education for postregistration training of medical doctors: systematic review by the Digital Health Education Collaboration

Background: Globally, online and local area network–based (LAN) digital education (ODE) has grown in popularity. Blended learning is used by ODE along with traditional learning. Studies have shown the increasing potential of these technologies in training medical doctors; however, the evidence for its effectiveness and cost-effectiveness is unclear. Objective: This systematic review evaluated the effectiveness of online and LAN-based ODE in improving practicing medical doctors’ knowledge, skills, attitude, satisfaction (primary outcomes), practice or behavior change, patient outcomes, and cost-effectiveness (secondary outcomes). Methods: We searched seven electronic databased for randomized controlled trials, cluster-randomized trials, and quasi-randomized trials from January 1990 to March 2017. Two review authors independently extracted data and assessed the risk of bias. We have presented the findings narratively. We mainly compared ODE with self-directed/face-to-face learning and blended learning with self-directed/face-to-face learning. Results: A total of 93 studies (N=16,895) were included, of which 76 compared ODE (including blended) and self-directed/face-to-face learning. Overall, the effect of ODE (including blended) on postintervention knowledge, skills, attitude, satisfaction, practice or behavior change, and patient outcomes was inconsistent and ranged mostly from no difference between the groups to higher postintervention score in the intervention group (small to large effect size, very low to low quality evidence). Twenty-one studies reported higher knowledge scores (small to large effect size and very low quality) for the intervention, while 20 studies reported no difference in knowledge between the groups. Seven studies reported higher skill score in the intervention (large effect size and low quality), while 13 studies reported no difference in the skill scores between the groups. One study reported a higher attitude score for the intervention (very low quality), while four studies reported no difference in the attitude score between the groups. Four studies reported higher postintervention physician satisfaction with the intervention (large effect size and low quality), while six studies reported no difference in satisfaction between the groups. Eight studies reported higher postintervention practice or behavior change for the ODE group (small to moderate effect size and low quality), while five studies reported no difference in practice or behavior change between the groups. One study reported higher improvement in patient outcome, while three others reported no difference in patient outcome between the groups. None of the included studies reported any unintended/adverse effects or cost-effectiveness of the interventions. Conclusions: Empiric evidence showed that ODE and blended learning may be equivalent to self-directed/face-to-face learning for training practicing physicians. Few other studies demonstrated that ODE and blended learning may significantly improve learning outcomes compared to self-directed/face-to-face learning. The quality of the evidence in these studies was found to be very low for knowledge. Further high-quality randomized controlled trials are required to confirm these findings

Underground workspaces : a human factors approach

With increasing population density in urban areas, underground space use in these urban centres is also on the rise. This can be in the form of more traditional underground (UG) facilities, such as water treatment plants and subway stations, but also more diversified uses such as underground offices and data centres. As these relatively novel underground workspaces are constructed, we need to take a human centric approach to ensure that the workers are happy and healthy. When designing any space, it is important to consider the relationships between the environmental, architectural characteristics and behavior and wellbeing. This is crucial in underground developments, as the initial cost of developing an underground space is significantly higher (at least in the short term) than aboveground and would have to be offset by a longer building life. Previous studies show negative attitudes towards working underground and hint at possible psychological and health complaints. Major themes include lighting and circadian rhythms, metabolic changes and claustrophobia. However, these studies are over thirty years old and mainly concentrate on self-report measures. To respond to this challenge, we have systematically examined the relationship between underground spaces and human performance in a 4 year research program. Using mixed methods such as psychophysiological measurements, cognitive tests and interviews, we examine the architectural and engineering choices that could impact or mitigate specific issues related to underground work environment