BackgroundWe conducted a systematic review of mathematical models of transmission dynamic of Clostridium difficile infection (CDI) in healthcare settings, to provide an overview of existing models and their assessment of different CDI control strategies.MethodsWe searched MEDLINE, EMBASE and Web of Science up to February 3, 2016 for transmission-dynamic models of Clostridium difficile in healthcare settings. The models were compared based on their natural history representation of Clostridium difficile, which could include health states (S-E-A-I-R-D: Susceptible-Exposed-Asymptomatic-Infectious-Resistant-Deceased) and the possibility to include healthcare workers and visitors (vectors of transmission). Effectiveness of interventions was compared using the relative reduction (compared to no intervention or current practice) in outcomes such as incidence of colonization, CDI, CDI recurrence, CDI mortality, and length of stay.ResultsNine studies describing six different models met the inclusion criteria. Over time, the models have generally increased in complexity in terms of natural history and transmission dynamics and number/complexity of interventions/bundles of interventions examined. The models were categorized into four groups with respect to their natural history representation: S-A-I-R, S-E-A-I, S-A-I, and S-E-A-I-R-D. Seven studies examined the impact of CDI control strategies. Interventions aimed at controlling the transmission, lowering CDI vulnerability and reducing the risk of recurrence/mortality were predicted to reduce CDI incidence by 3–49%, 5–43% and 5–29%, respectively. Bundles of interventions were predicted to reduce CDI incidence by 14–84%.ConclusionsAlthough CDI is a major public health problem, there are very few published transmission-dynamic models of Clostridium difficile. Published models vary substantially in the interventions examined, the outcome measures used and the representation of the natural history of Clostridium difficile, which make it difficult to synthesize results and provide a clear picture of optimal intervention strategies. Future modeling efforts should pay specific attention to calibration, structural uncertainties, and transparent reporting practices.

The minimum annual volume of 500 mammograms required in North America is justified; radiologist accuracy may be compromised if interpretive volume is consistently less than this requirement. Raising interpretive volume may help to reduce the frequency of false positives without loss of sensitivity. Possible gains in accuracy may be greater with increases in volume of up to approximately 3000 mammograms interpreted annually.

Despite measures to ensure high-quality imaging, including CAR accreditation, approximately half of this random sample of screening mammograms failed the CAR quality standards. It would be important to define quality targets for screening mammograms carried out in daily practice to interpret such observations.

BackgroundProstate cancer is the most commonly diagnosed cancer in north-American men. Few dietary or lifestyle interventions have been tested to prevent prostate cancer progression. Omega-3 fatty acid supplementation represents a promising intervention for prostate cancer patients. The aim of the study is to evaluate the effects of long-chain omega-3 polyunsaturated fatty acids (LCn3), more precisely eicosapentaenoic acid monoacylglyceride (MAG-EPA) supplementation, on prostate cancer proliferation, inflammation mediators and quality of life among men who will undergo radical prostatectomy.Methods/designWe propose a phase IIb, randomized, double-blind placebo-controlled trial of MAG-EPA supplementation for 130 men who will undergo radical prostatectomy as treatment for a prostate cancer of Gleason score ≥ 7 in an academic cancer center in Quebec City. Participants will be randomized to 6 capsules of 625 mg of fish oil (MAG-EPA) per capsule containing 500 mg of EPA daily or to identically looking capsules of high oleic acid sunflower oil (HOSO) as placebo. The intervention begins 4 to 10 weeks prior to radical prostatectomy (baseline) and continues for one year after surgery. The primary endpoint is the proliferative index (Ki-67) measured in prostate cancer cells at radical prostatectomy. A secondary endpoint includes prostate tissue levels of inflammatory mediators (cytokines and proteins) at time of radical prostatectomy. Changes in blood levels of inflammatory mediators, relative to baseline levels, at time of radical prostatectomy and 12 months after radical prostatectomy will also be evaluated. Secondary endpoints also include important aspects of psychosocial functioning and quality of life such as depression, anxiety, sleep disturbances, fatigue, cognitive complaints and prostate cancer-specific quality of life domains. The changes in these outcomes, relative to baseline levels, will be evaluated at 3, 6, 9 and 12 months after radical prostatectomy.DiscussionThe results from this trial will provide crucial information to clarify the role of omega-3 supplementation on prostate cancer proliferation, inflammation and quality of life.Trial registrationClinicalTrials.gov Identifier: NCT02333435. Registered on December 17, 2014. Last updated September 6, 2016.Electronic supplementary materialThe online version of this article (10.1186/s12885-017-3979-9) contains supplementary material, which is available to authorized users.

Although not all mammograms in the Quebec screening program met the optimum quality required by the Canadian Association of Radiologists or American College of Radiology accreditation, the screening mammograms produced in this population-based organized screening program reached a high enough level of quality so that the remaining variation in quality is too little to impair screening sensitivity.

Breast cancer screening enables early detection of breast cancer which leads to a reduction in mortality.1,2 The Quebec breast cancer screening program began in 1998 and offers women aged 50-69 a biennial screening mammography. 3 Since 2002, three mammography mobile units were progressively added to the program. The program relies on two motorized units and a portable unit transported by plane or boat that extends screening services to regions not accessible by land. In the present study, we use the term "mobile units" to refer to both (motorized and portable) types of mammography units. The purpose of these units is to provide services to regions not covered by fixed centres. In addition, they can provide temporary relief to fixed centres that have insufficient resources to ensure timely breast screening.Mobile units have been added to screening programs in various countries to increase geographical accessibility to breast cancer screening. 4 Studies have shown that mobile units are effective at improving the participation rate, 5-7 that mobile units can decrease barriers to screening for hard-to-reach populations 8 and that educational interventions associated with mobile unit visits can increase adherence.9 However, mobile units have different operating practices when compared to stationary (fixed) centres in terms of personnel, work conditions and environment. Moreover, screening in mobile units may require ongoing calibration of instruments, and where analogue units are used, films cannot be developed onsite. These differences could have an impact on screening outcomes but there are few studies comparing the performance of mobile units to fixed sites. 10,11 These studies focussed primarily on comparing costs and other elements (price, access, quality assurance). In some studies, screening results for mobile units were reported but were not compared to fixed centres. 8,[12][13][14] The aims of this study were to evaluate the contribution of mobile mammography units to participation rate, and to compare screening performance between mobile units and fixed centres in the organized mammography screening program of Quebec, Canada. METHODS Population and dataAll eligible women residing in the province, aged 50-69 years, are invited to participate in the Quebec breast cancer screening program. Each participant is asked to sign a written consent form to allow the collection of personal characteristics and screening information. Over the study period, 98% of participants provided written consent. ABSTRACT BACKGROUND: The aims of this study were to evaluate the contribution of mobile mammography units to participation rate and to compare their performance to fixed screening centres within the organized mammography screening program of Quebec, Canada.

BackgroundWe estimated the relations of sociodemographic, organizational, disease, and treatment variables

Artifacts can have a substantial effect on the FP rate. The effect of overall mammography quality on the FP rate may also be substantial and needs to be clarified.