Skewed Factor Models Using Selection Mechanisms

Traditional factor models explicitly or implicitly assume that the factors follow a multivariate normal distribution; that is, only moments up to order two are involved. However, it may happen in real data problems that the first two moments cannot explain the factors. Based on this motivation, here we devise three new skewed factor models, the skew-normal, the skew-t, and the generalized skew-normal factor models depending on a selection mechanism on the factors. The ECME algorithms are adopted to estimate related parameters for statistical inference. Monte Carlo simulations validate our new models and we demonstrate the need for skewed factor models using the classic open/closed book exam scores dataset

Malaria standby emergency treatment (SBET) for travellers visiting malaria endemic areas: a systematic review and meta-analysis.

Malaria prevention methods for travellers to low or moderate malaria risk areas vary and remain controversial. Standby emergency treatment (SBET) for malaria is one possible strategy increasingly recommended since 1988 with little evidence on its effectiveness or how it is truly being used. A systematic review and meta-analysis were performed based on a structured search in Embase, Medline, PubMed, Cochrane and Web of Science on 7 September 2018. The primary outcome was the overall prevalence of SBET use in travellers, and secondary outcomes were the proportion carrying SBET, the response to fever [use of SBET, health facility attendance and use of malaria rapid diagnostic test (mRDT)], adverse events to SBET and the proportion using SBET incorrectly (incorrect dosage/duration). The pooled SBET use prevalence was analysed using a random effects model. A descriptive summary was done to present secondary outcomes. The study protocol was registered with PROSPERO CRD42018103703. A total of 11 studies were eligible for inclusion among the 1027 titles identified by our search. The studies included 7/11 prospective cohort studies that recruited pre-travel clinic attendees in Europe and 4/11 cross-sectional studies, of which 3 recruited travellers at airports before their return home from Southeast Asia and Africa and 1 from an employee registry including long-term travellers. The overall pooled prevalence of SBET use among the 26 403 travellers was 2.5% (95% confidence interval, 1.1-4.3%; range, 0.4-10.8%). There was significant variation in the proportion of travellers carrying SBET medication (40-100%), the proportion of travellers with appropriate response to fever (23-100%), adverse events (0-33%) and incorrect dosage/duration of SBET (0-100%). Adherence to the proposed recommendations for SBET use, notably the response to fever, was poor. If the use of SBET is to be pursued, modifications to the current SBET strategy should be considered, such as better selection of travellers at higher risk for malaria and the potential addition of mRDTs

Les étudiant·e·s en médecine mènent une recherche dans La communauté. [Male/female medical students conduct research in the community]

Pendant quatre semaines, les étudiant(e)s en médecine de 3e année de l'Université de Lausanne mènent une enquête dans la communauté sur le sujet de leur choix. L'objectif de ce module est de faire découvrir aux futurs médecins les déterminants non biomédicaux de la santé, de la maladie et de l'exercice de la médecine : les styles de vie, les facteurs psychosociaux et culturels, l'environnement, les décisions politiques, les contraintes économiques, les questions éthiques, etc. Par groupes de cinq, les étudiant(e)s commencent par définir une question de recherche originale et en explorent la littérature scientifique. Leur travail de recherche les amène à entrer en contact avec le réseau d'acteurs de la communauté concernés, professionnels ou associations de patients dont ils analysent les rôles et influences respectives. Chaque groupe est accompagné par un(e) tuteur(trice), enseignant(e) de la Faculté de biologie et de médecine de l'Université de Lausanne. Les étudiant(e)s présentent la synthèse de leurs travaux pendant un congrès de deux jours à la fin du module. Quatre travaux parmi les plus remarquables ont été choisis pour être publiés dans la Revue Médicale Suisse et Primary Care

Mosquito nets for the elderly?

Nine-year follow-up (ending 1999) of survival of 3738 individuals in a malaria-endemic area of Papua New Guinea found that the use of mosquito nets was associated with a large reduction in mortality in people aged ⩾40 years as well as in children aged <5 years. There may be substantial benefits of malaria transmission reduction for older people, that have been overlooked in public health programmes and burden of disease calculation

Medication exposure during pregnancy: a pilot pharmacovigilance system using health and demographic surveillance platform.

BACKGROUND: There is limited safety information on most drugs used during pregnancy. This is especially true for medication against tropical diseases because pharmacovigilance systems are not much developed in these settings. The aim of the present study was to demonstrate feasibility of using Health and Demographic Surveillance System (HDSS) as a platform to monitor drug safety in pregnancy. METHODS: Pregnant women with gestational age below 20 weeks were recruited from Reproductive and Child Health (RCH) clinics or from monthly house visits carried out for the HDSS. A structured questionnaire was used to interview pregnant women. Participants were followed on monthly basis to record any new drug used as well as pregnancy outcome. RESULTS: 1089 pregnant women were recruited; 994 (91.3%) completed the follow-up until delivery. 98% women reported to have taken at least one medication during pregnancy, mainly those used in antenatal programmes. Other most reported drugs were analgesics (24%), antibiotics (17%), and antimalarial (15%), excluding IPTp. Artemether-lumefantrine (AL) was the most used antimalarial for treating illness by nearly 3/4 compared to other groups of malaria drugs. Overall, antimalarial and antibiotic exposures in pregnancy were not significantly associated with adverse pregnancy outcome. Iron and folic acid supplementation were associated with decreased risk of miscarriage/stillbirth (OR 0.1; 0.08 - 0.3). CONCLUSION: Almost all women were exposed to medication during pregnancy. Exposure to iron and folic acid had a beneficial effect on pregnancy outcome. HDSS proved to be a useful platform to establish a reliable pharmacovigilance system in resource-limited countries. Widening drug safety information is essential to facilitate evidence based risk-benefit decision for treatment during pregnancy, a major challenge with newly marketed medicines

Observational study on the consumption of recreational drugs and alcohol by Swiss travelers.

BACKGROUND: Studies carried out on specific travelers' groups such as students describe an increase in the consumption of alcohol and drugs during travel and vacation time. The present study investigates the risk behaviors (alcohol and drugs) in a general adult population in Switzerland travelling abroad who visited a travel clinic before departure. METHODS: This retrospective study was conducted in a travel clinic between January 2006 and December 2008. 14,496 patients came to the clinic for a pre-travel consultation. 3,537 of them answered a questionnaire about their life habits in Switzerland and during their last trip. The only exclusion criterion was an age inferior to 18 years old.The consumption habits of drugs and at-risk alcohol intake (8 standard drinks (SD) per week for women and 15 SD for men) was analyzed according to gender, sex, destination and profession. Predictors of adopting a risky behavior between habits in Switzerland and during their previous trip were also analyzed. RESULTS: 7% (229/3477) of participants declared having at-risk alcohol consumption in Switzerland and 14% (473/3275 [95% CI 13-16]) during their trip. 9% (332/3527) of the participants used drugs in Switzerland and 5% (178/3481) during their trip. Risk factors for at-risk alcohol consumption during a trip were: at-risk alcohol consumption in Switzerland (OR 31[95% CI 21-45]), smoking (1.7 [95% CI 1-2]), use of drugs in Switzerland (OR 2.2 [95% CI 2-3]), leisure travel (OR 1.6 [95% CI 1-2]) and managerial professions (OR 1.8 [95% CI 1-3]). Risk factors for the use of drugs during a trip were: alcohol consumption in Switzerland (OR 2.1 [95% CI 1-4]), smoking (OR 1.9 [95% CI 1-3]), and use of drugs in Switzerland (OR 29.7 [95% CI 19-45]). CONCLUSIONS: At-risk alcohol consumption and, to a lesser extent, use of drugs, affect a large number of travelers which expose them to health problems during a trip. Exploring the alcohol and drugs consumption patterns of people visiting a travel clinic should be part of the pre-travel routine consultation and would allow to identifying people who would benefit most from a specific prevention

Mass drug administration for malaria elimination: do we understand the settings well enough?

Mass drug administration (MDA) of antimalarials has re-emerged as a recommended tool for interrupting malaria transmission, but evidence from low endemicity settings is scarce. A trial in Zanzibar found that two rounds of MDA made no significant impact on malaria incidence, and many questions on the optimal mode and setting for implementing MDA remain unanswered. A more thorough understanding of local sources and drivers of transmission, and a better toolbox for evaluating interventions in near-elimination settings are essential.Please see related research article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-018-1202-8