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Estimating and selecting risk factors with extremely low prevalences of exposure for a binary outcome is a challenge because classical standard techniques, markedly logistic regression, often fail to provide meaningful results in such settings. While penalized regression methods are widely used in high-dimensional settings, we were able to show their usefulness in low-dimensional settings as well. Specifically, we demonstrate that Firth correction, ridge, the lasso and boosting all improve the estimation for low-prevalence risk factors. While the methods themselves are well-established, comparison studies are needed to assess their potential benefits in this context. This is done here using the dataset of a large unmatched case-control study from France (2005-2008) about the relationship between prescription medicines and road traffic accidents and an accompanying simulation study. Results show that the estimation of risk factors with prevalences below 0.1% can be drastically improved by using Firth correction and boosting in particular, especially for ultra-low prevalences. When a moderate number of low prevalence exposures is available, we recommend the use of penalized techniques. [ABSTRACT FROM AUTHOR]

Background: Reliable epidemiological data on Alzheimer's disease are scarce. However, these are necessary to adapt healthcare policy in terms of prevention, care and social needs related to this condition. To estimate the prevalence rate in the Alpes-Maritimes on the French Riviera, with a population of one million, we present a capture-recapture procedure applied to cases of Alzheimer’s disease, based on two epidemiological surveillance systems. Methods: To estimate the total number of patients affected by Alzheimer's disease, a capture-recapture study included a cohort of patients with Alzheimer's disease or receiving medications only eligible for use for this condition, recorded by a specific health insurance information system (Health Insurance Cohort, HIC), and those registered in the French National Alzheimer’s Data Bank (“Banque Nationale Alzheimer”, BNA) in 2010 and 2011. We applied Bayesian estimation of the Mt ecological model, taking into account age and gender as covariates, i.e. factors of inhomogeneous catchability. Results: Overall, 5,562 patients with Alzheimer's disease were recorded, of whom only 856 were common to both information systems. Mean age and F/M sex ratio differed between BNA and HIC surveillance systems, 81 vs 84 years and 2.7 vs 3.2, respectively. A Bayesian estimation, with age and gender as covariates, yields an estimate of 15,060 cases of Alzheimer's disease [95%HPDI: 14,490–15,630] in the Alpes-Maritimes. The completeness of the HIC and BNA databases were respectively of 25.4% and 17.2%. The estimated prevalence rate among the population over 65 years old was 6.3% in 2010–2011. Conclusions: This study demonstrates that it is possible to determine the number of subjects affected by Alzheimer's disease in a geographical unit, using available data from two existing surveillance systems in France, i.e. 15,060 cases in the Alpes-Maritimes. This is the first stage of a population-based approach in view of adapting available resources to the population’s needs. [ABSTRACT FROM AUTHOR]

Bovine tuberculosis (bTB) is a common disease of cattle and wildlife, with economic repercussions and implications for animal and human health. The surveillance of bTB in wildlife is particularly important, to shed light on the epidemiological role of wild species and for the adaptation of control measures. In France, a bTB surveillance system for free-ranging wildlife, the Sylvatub system, was launched in 2011 on wild boars, red deer, roe deer and badgers. It relies on active and passive surveillance activities, constrained by practical difficulties, such as the accessibility of wild animals, and regulatory rules for the trapping of badgers, for example. We report here the first assessment of stakeholders’ perceptions of the Sylvatub system and its acceptability, based on 20 individual semi-structured interviews with three types of stakeholder (collectors, coordinators, officers) in areas with different rates of bTB infection. With the caveat that these findings cannot be assumed to be representative of the national situation, we found that the Sylvatub system was considered useful by all the stakeholders interviewed. Those from the world of hunting participate in surveillance mostly to help livestock farmers, who are not systematically involved in bTB surveillance in wildlife. Many practical and regulatory constraints were raised, which could be offset by recognition of the work done by the “hunting community”, to maintain the willingness of these individuals to participate. We also identified a need for improvements in communication and information. Qualitative information, such as that collected here, is essential to improve our understanding of the reasons favoring and disfavoring participation in surveillance, and should be taken into account in the evaluation process. These results are relevant to hunters and to veterinary authorities wishing to identify the determinants of participation in the Sylvatub system. They could provide support for decision-making processes to improve surveillance strategies. [ABSTRACT FROM AUTHOR]

Objective: HIV testing is an important tool in the management of the HIV epidemic among key populations. We aimed to explore the dynamic of first-time HIV testing in France for sub-Saharan migrants after their arrival. Methods: ANRS-Parcours is a retrospective life-event survey conducted from 2012 to 2013 in healthcare facilities in the Paris region, among 926 sub-Saharan HIV-infected migrants and 763 non-infected migrants. After describing the time to first HIV test in France and associated circumstances, we performed a discrete-time logistic regression to analyze the influence of socioeconomic position, contact with the healthcare system and sexual behaviors, on first-time HIV testing in France in migrants who arrived after 2000. Results: Median first-time HIV testing occurred during the second year spent in France for non-infected men and women in both groups, and during the first year for men of the HIV group. The probability of testing increased with hospitalization and pregnancy for women of both groups. For non-infected men unemployment and absence of a residence permit were associated with an increased probability of HIV testing [respectively, OR = 2.2 (1.2–4.1) and OR = 2.0 (1.1–3.5)]. Unemployment was also associated with an increased probability of first-time HIV-testing for women of the HIV group [OR: 1.7 (1.0–2.7)]. Occasional and multiple sexual relationships were associated with an increased probability of first-time testing only for HIV-infected women [OR: 2.2 (1.2–4.0) and OR = 2.4 (1.3–4.6)]. Conclusion: Access to first HIV testing in France is promoted by contact with the health care system and is facilitated for unemployed and undocumented migrants after arrival.However, testing should be offered more systematically and repeated in order to reduce time between HIV infection and diagnosis, especially for deprived people which are particularly vulnerable regarding HIV infection. [ABSTRACT FROM AUTHOR]

Human leptospirosis is a zoonotic and potentially fatal disease that has increasingly been reported in both developing and developed countries, including France. However, our understanding of the basic aspects of the epidemiology of this disease, including the source of Leptospira serogroup Australis infections in humans and domestic animals, remains incomplete. We investigated the genetic diversity of Leptospira in 28 species of wildlife other than rats using variable number tandem repeat (VNTR) and multispacer sequence typing (MST). The DNA of pathogenic Leptospira was detected in the kidney tissues of 201 individuals out of 3,738 tested individuals. A wide diversity, including 50 VNTR profiles and 8 MST profiles, was observed. Hedgehogs and mustelid species had the highest risk of being infected (logistic regression, OR = 66.8, CI95% = 30.9–144 and OR = 16.7, CI95% = 8.7–31.8, respectively). Almost all genetic profiles obtained from the hedgehogs were related to Leptospira interrogans Australis, suggesting the latter as a host-adapted bacterium, whereas mustelid species were infected by various genotypes, suggesting their interaction with Leptospira was different. By providing an inventory of the circulating strains of Leptospira and by pointing to hedgehogs as a potential reservoir of L. interrogans Australis, our study advances current knowledge on Leptospira animal carriers, and this information could serve to enhance epidemiological investigations in the future. [ABSTRACT FROM AUTHOR]

Context: HIV self-tests are currently being introduced in France with the aim of promoting screening both for the general population and for high-risk populations. Objective: The current study aimed to identify and compare the information and support needs of the different target population groups. Methods: The Delphi process was used to synthesize expert opinions for each population group. Experts were chosen for their experience and expertise in the area of HIV and HIV screening for each population. Each group developed recommendations for a specific population: six high HIV prevalence populations (men who have sex with men; transgender people; substance users; migrants from sub-Saharan Africa; French West Indies; French Guiana) and two low prevalence populations (the general population; people under 25). Each group included expertise from four areas: research, screening and care, policy-making, and community groups. Results: A final total of 263 recommendations were grouped into eight main themes: Communicating at both national and community levels about self-test arrival (24% of all recommendations); Providing information adapted to the different community groups’ needs (23%); Providing counselling on self-test use and access to care (15%); Making self-tests available to all in terms of accessibility and cost (13%); Preparing community healthcare and screening systems for the arrival of the self-test (11%); Approving only high quality self-tests (6%); Defending self-test users’ legal rights (5%); Evaluating self-test use (3%). Although a large number of recommendations were common to several groups of experts, the study highlighted a certain number of recommendations specific to each different population group, particularly with regard to information content and access both to information and to the self-tests themselves. Conclusion: Results from the current study should make a significant contribution to policy decisions concerning catering for the specific access, information and support needs of different potential HIV self-test user groups in France. [ABSTRACT FROM AUTHOR]

Background: Empirical social contact patterns are essential to understand the spread of infectious diseases. To date, no such data existed for France. Although infectious diseases are frequently seasonal, the temporal variation of contact patterns has not been documented hitherto. Methods: COMES-F is the first French large-scale population survey, carried out over 3 different periods (February-March, April, April-May) with some participants common to the first and the last period. Participants described their contacts for 2 consecutive days, and reported separately on professional contacts when typically over 20 per day. Results: 2033 participants reported 38 881 contacts (weighted median [first quartile-third quartile]: 8[5–14] per day), and 54 378 contacts with supplementary professional contacts (9[5–17]). Contrary to age, gender, household size, holidays, weekend and occupation, period of the year had little influence on the number of contacts or the mixing patterns. Contact patterns were highly assortative with age, irrespective of the location of the contact, and gender, with women having 8% more contacts than men. Although most contacts occurred at home and at school, the inclusion of professional contacts modified the structure of the mixing patterns. Holidays and weekends reduced dramatically the number of contacts, and as proxies for school closure, reduced R0 by 33% and 28%, respectively. Thus, school closures could have an important impact on the spread of close contact infections in France. Conclusions: Despite no clear evidence for temporal variation, trends suggest that more studies are needed. Age and gender were found important determinants of the mixing patterns. Gender differences in mixing patterns might help explain gender differences in the epidemiology of infectious diseases. [ABSTRACT FROM AUTHOR]

Objective: In high-income countries, the social and epidemiological contexts surrounding homosexuality and AIDS have changed profoundly in recent decades. This work sought to examine key indicators of the long-term sexual trajectories of successive generations of men who have sex with men (MSM) in France. Methods: We performed a longitudinal analysis of the French Gay Press surveys, which were self-administered socio-behavioural questionnaires, repeated from 1985 to 2011 in the gay press, and on the internet in 2004 and 2011. An age-cohort analysis using graphical representations and multivariate logistic regressions was conducted among participants aged 18-59 (N=38 821). Results: First sexual intercourse occurred more often with a male partner in younger generations than in older ones: 76.0% in MSM who turned 18 in 1956-1959, 75.6% in 1980-1983, 83.7% in 2008-2011, poverall=0.0002). Every generation showed the same pattern of sexual trajectory between 1985 and 2011: globally, the frequency of masturbation increased from the 1985 survey to the early 1990s and then decreased from the late 1990s to the end of the study period. Inversely, the frequency of oral and anal sex decreased in the mid-1980s and increased from 1990 to 2011. The frequency of both oral sex and anal intercourse is currently quite high, regardless of generation (>95% and around 80%, respectively). Compared to their predecessors, recent generations of young MSM reported more frequent oral and anal sex, but fewer male partners in the previous 12 months. Discussion: While the increased frequency of first intercourse with a man over successive generations since the 1970s may be related to reduced social pressure for heterosexuality, there is evidence that sexual norms among MSM are widespread, with practices spreading across age groups and generations. Although AIDS profoundly affected sexual practices in the 1980s, further AIDS-related events (discovery of HIV antiretroviral drugs and their use in prevention) do not appear to have accentuated ongoing trends in sexual practices. [ABSTRACT FROM AUTHOR]

To study the dynamics of bovine tuberculosis (bTB) in France, 4,654 M. bovis strains isolated mainly from livestock and wildlife since 1978 were characterized by spoligotyping and MLVA based on MIRU-VNTR. In our study spoligotyping allowed the discrimination of 176 types although 3 spoligotypes are predominant and account for more than half of the total strain population: SB0120 (26%), SB0134 (11%) and SB0121 (6%). In addition, 11% of the isolates, principally from Southern France, showing close spoligotypes and MIRU-VNTR types have been gathered in a family designated as the “F4-family”. MLVA typing allowed extensive discrimination, particularly for strains with predominant spoligotypes, with a total of 498 genotypes, several of which were highly regionalized. The similarity of the strains’ genetic relationships based on spoligotyping and MIRU-VNTR markers supports the co-existence of different clonal populations within the French M. bovis population. A genetic evolution of the strains was observed both geographically and in time. Indeed, as a result of the reduction of bTB due to the national control campaigns, a large reduction of the strains’ genetic variability took place in the last ten years. However, in the regions were bTB is highly prevalent at present, cases in both livestock and in wildlife are due to the spread of unique local genotype profiles. Our results show that the highly discriminating genotyping tools used in this study for molecular studies of bTB are useful for addressing pending questions, which would lead to a better insight into the epidemiology of the disease, and for finding proper solutions for its sustainable control in France. [ABSTRACT FROM AUTHOR]

Background: The aims of this study were 1) to confirm that combinations of brief geriatric assessment (BGA) items were significant risk factors for prolonged LHS among geriatric patients hospitalized in acute care medical units after their admission to the emergency department (ED); and 2) to determine whether these combinations of BGA items could be used as a prognostic tool of prolonged LHS. Methods: Based on a prospective observational cohort design, 1254 inpatients (mean age ± standard deviation, 84.9±5.9 years; 59.3% female) recruited upon their admission to ED and discharged in acute care medical units of Angers University Hospital, France, were selected in this study. At baseline assessment, a BGA was performed and included the following 6 items: age ≥85years, male gender, polypharmacy (i.e., ≥5 drugs per day), use of home-help services, history of falls in previous 6 months and temporal disorientation (i.e., inability to give the month and/or year). The LHS in acute care medical units was prospectively calculated in number of days using the hospital registry. Results: Area under receiver operating characteristic (ROC) curves of prolonged LHS of different combinations of BGA items ranged from 0.50 to 0.57. Cox regression models revealed that combinations defining a high risk of prolonged LHS, identified from ROC curves, were significant risk factors for prolonged LHS (hazard ratio >1.16 with P>0.010). Kaplan-Meier distributions of discharge showed that inpatients classified in high-risk group of prolonged LHS were discharged later than those in low-risk group (P<0.003). Prognostic value for prolonged LHS of all combinations was poor with sensitivity under 77%, a high variation of specificity (from 26.6 to 97.4) and a low likelihood ratio of positive test under 5.6. Conclusion: Combinations of 6-item BGA tool were significant risk factors for prolonged LHS but their prognostic value was poor in the studied sample of older inpatients. [ABSTRACT FROM AUTHOR]

Introduction: We aimed to study the relationships between educational level, women's knowledge about cervical cancer (CC), and acceptance of HPV vaccination for their daughters. Methods: We analysed data from a quantitative (self-administrated questionnaire) and qualitative (semi-structured interviews) cross-sectional study performed in 2008 among 1,229 French 18–65-year-old women recruited by general practitioners. Women were categorized into three educational level groups: low (LEL: 43.9%), medium (MEL: 33.4%) and high (HEL: 22.6%). Results: Knowledge about CC and its prevention was lower among LEL women. In the 180 mothers of 14–18-year-old daughters (99 LEL, 54 MEL, 45 HEL), acceptance of HPV vaccine was higher in LEL (60.4%) and MEL (68.6%) than in HEL mothers (46.8%). Among LEL mothers, those who were favourable to HPV vaccination were more likely to be young (OR = 8.44 [2.10–34.00]), to be vaccinated against hepatitis B (OR = 4.59 [1.14–18.52]), to have vaccinated their children against pneumococcus (OR = 3.52 [0.99–12.48]) and to present a history of abnormal Pap smear (OR = 6.71 [0.70–64.01]). Conclusion: Although LEL women had poorer knowledge about CC and its prevention, they were more likely to accept HPV vaccination than HEL mothers. [ABSTRACT FROM AUTHOR]

Background: The present study aimed to describe exposure and attitudes of French medical residents towards pharmaceutical industry. The study was performed shortly after the Mediator affair which revealed several serious conflicts of interest inside the French health system. Methods and Findings: A cross-sectional study was implemented among residents from 6 French medical faculties. Independent education in pharmacology, attitudes towards the practices of pharmaceutical sales representatives, opinions concerning the pharmaceutical industry, quality of information provided by the pharmaceutical industry, and opinions about pharmaceutical company sponsorship were investigated through a web-based questionnaire. We also assessed potential changes in resident attitudes following the Mediator affair. The mean value of exposure to drug companies was 1.9 times per month. Global opinions towards drug company information were negative for 42.7% of the residents and positive for only 8.2%. Surprisingly, 81.6% of residents claimed that they had not changed their practices regarding drug information since the Mediator affair. Multivariate analyses found that residents in anesthesiology were less likely to be exposed than others (OR = 0.17 CI95% [0.05–0.61]), exposure was significantly higher at the beginning of residence (p<0.001) and residents who had a more positive opinion were more frequently exposed to drug companies (OR = 2.12 CI95% [1.07–4.22]). Conclusions: Resident exposure to drug companies is around 1 contact every 2 weeks. Global opinion towards drug information provided by pharmaceutical companies was negative for around 1 out of 2 residents. In contrast, residents tend to consider the influences of the Mediator affair on their practice as relatively low. This survey enabled us to identify profiles of residents who are obviously less exposed to pharmaceutical industry. Current regulatory provisions are not sufficient, indicating that further efforts are necessary to develop a culture of disclosure of conflict of interest and of transparency in residents. [ABSTRACT FROM AUTHOR]

: Malnutrition is a frequent condition in elderly people, especially in nursing homes and geriatric wards. Its frequency is less well known among elderly living at home. The objective of this study was to describe the nutritional status evaluated by the Mini Nutritional Assessment (MNA) of elderly community-dwellers living in rural and urban areas in France and to investigate its associated factors. Methods: Subjects aged 65 years and over from the Approche Multidisciplinaire Intégrée (AMI) cohort (692 subjects living in a rural area) and the Three-City (3C) cohort (8,691 subjects living in three large urban zones) were included. A proxy version of the MNA was reconstructed using available data from the AMI cohort. Sensitivity and specificity were used to evaluate the agreement between the proxy version and the standard version in AMI. The proxy MNA was computed in both cohorts to evaluate the frequency of poor nutritional status. Factors associated with this state were investigated in each cohort separately. Results: In the rural sample, 38.0% were females and the mean age was 75.5 years. In the urban sample, 60.3% were females and the mean age was 74.1 years. Among subjects in living in the rural sample, 7.4% were in poor nutritional status while the proportion was 18.5% in the urban sample. Female gender, older age, being widowed, a low educational level, low income, low body mass index, being demented, having a depressive symptomatology, a loss of autonomy and an intake of more than 3 drugs appeared to be independently associated with poor nutritional status. Conclusion: Poor nutritional status was commonly observed among elderly people living at home in both rural and urban areas. The associated factors should be further considered for targeting particularly vulnerable individuals. [ABSTRACT FROM AUTHOR]