L. Rachid Salmi

Determinants of transfusion‐associated bacterial contamination: results of the French Bacthem Case‐Control Study

BACKGROUND : Transfusion‐associated bacterial contamination (TABC), probably the most frequent transfusion‐transmitted infection, may induce serious adverse events. Systematic information and documentation on determinants are lacking.

Methodological issues and research recommendations for prognosis after mild traumatic brain injury: results of the International Collaboration on Mild Traumatic Brain Injury Prognosis.

The International Collaboration on Mild Traumatic Brain Injury (MTBI) Prognosis performed a comprehensive search and critical review of the literature from 2001 to 2012 to update the 2002 best-evidence synthesis conducted by the World Health Organization Collaborating Centre for Neurotrauma, Prevention, Management and Rehabilitation Task Force on the prognosis of MTBI. Of 299 relevant studies, 101 were accepted as scientifically admissible. The methodological quality of the research literature on MTBI prognosis has not improved since the 2002 Task Force report. There are still many methodological concerns and knowledge gaps in the literature. Here we report and make recommendations on how to avoid methodological flaws found in prognostic studies of MTBI. Additionally, we discuss issues of MTBI definition and identify topic areas in need of further research to advance the understanding of prognosis after MTBI. Priority research areas include but are not limited to the use of confirmatory designs, studies of measurement validity, focus on the elderly, attention to litigation/compensation issues, the development of validated clinical prediction rules, the use of MTBI populations other than hospital admissions, continued research on the effects of repeated concussions, longer follow-up times with more measurement periods in longitudinal studies, an assessment of the differences between adults and children, and an account for reverse causality and differential recall bias. Well-conducted studies in these areas will aid our understanding of MTBI prognosis and assist clinicians in educating and treating their patients with MTBI.

Blood transfusion in a random sample of hospitals in France

BACKGROUND: Representative information on blood use is scarce. A large‐scale study of blood recipients and blood use in France was conducted.

A decision analysis model to assess the feasibility of the early detection of psychosis in the general population

The objective was to evaluate the feasibility of early detection of psychosis in the general population. Decision analysis was used to compare the effectiveness of early detection to that of detection as usual to prevent the occurrence of adverse outcomes (death, hospitalization, or unemployment) over 5 years in a hypothetical cohort of subjects aged from 15 to 34 years old. Decision analysis was based upon optimistic models with several assumptions favoring early detection. Sensitivity analyses were used to explore how the findings were affected by varying the different probabilities. Early detection would be effective in preventing the occurrence of adverse outcomes only if detection tests with high specificity (>88%) were available and if a high number of subjects were screened. The numbers needed to screen would be 20,000 subjects to prevent one death, 641 to prevent one hospitalization, and 847 to prevent one unemployment. A temporary conclusion of this decision analysis is that more specific screening instruments have to be developed and that further studies have to be carried out in unselected populations to establish the feasibility and effectiveness of early detection of psychosis.

Systematic screening for unsafe driving due to medical conditions: still debatable

BackgroundAssessing peoples ability to drive has become a public health concern in most industrialized countries. Although age itself is not a predictive factor of an increased risk for dangerous driving, the prevalence of medical conditions that may impair driving increases with age. Because the implementation of a screening for unsafe driving due to medical conditions is a public health issue, its usefulness should be judged using standardised criteria already proposed for screening for chronic disease. The aim of this paper is to propose standardised criteria suitable to assess the scientific validity of screening for unsafe driving due to medical conditions, and identify potential issues to be clarified before screening can be implemented and effective.DiscussionUsing criteria developed for screening for chronic diseases and published studies on driving with medical conditions, we specify six criteria to judge the opportunity of screening for unsafe driving due to medical conditions. This adaptation was needed because of the complexity of the natural history of medical conditions and their potential consequences on driving and road safety. We then illustrate that published studies pleading for or against screening for unsafe driving due to medical conditions fail to provide the needed documentation. Individual criteria were mentioned in 3 to 72% of 36 papers pleading for or against screening. Quantitative estimates of relevant indicators were provided in at most 42% of papers, and some data, such as the definition of an appropriate unsafe driving period were never provided.SummaryThe standardised framework described in this paper provides a template for assessing the effectiveness (or lack of effectiveness) of proposed measures for screening for unsafe driving due to medical conditions. Even if most criteria were mentioned in the published literature pleading for or against such a screening, the failure to find quantitative and evidence-based estimates of relevant indicators provides useful insight for further research.

Association between road vehicle collisions and recent medical contact in older drivers: a case-crossover study.

Objective: To estimate the association between past medical contacts and the risk of vehicle collision in a population of older drivers from the province of Quebec, Canada. Design: Case-crossover study. Setting: Quebec. Participants: 111 699 older drivers involved in at least one vehicle collision between January 1988 and December 2000. Main outcome measures: For each driver, the risk of having a vehicle collision while exposed and not exposed to a medical contact was compared. Separate conditional logistic regression analyses were conducted for all drivers and in four diagnostic-specific subgroups. Results: The study found a weak but statistically significant increased risk of all collisions being associated with a medical contact within 1 month before the collision, for all drivers (OR = 1.10, 95% CI 1.08 to 1.11) and for drivers with diabetes (OR = 1.07, 95% CI 1.03 to 1.11). Conclusion: Older drivers who have a collision are more likely to have been in contact with a physician shortly before the collision. These findings suggest that there might be an opportunity to detect medical conditions that put older drivers at higher risk of collision; however, further research is needed to assess the potential effectiveness and practical modalities of screening.

Emergency Trauma Care for Severe Injuries in a Moroccan Region: Conformance to French and World Health Organization Standards

&NA; In Morocco, injuries account for 11% of total burden of disease. Better organization of emergency care can improve the outcome of trauma patients. In Morocco, these services have been reorganized recently, but were never evaluated. The objective was to assess actual structure and processes of emergency trauma care in a Moroccan region. This comparative qualitative study was carried out in the region of Fez. The process and structure of contacting emergency care and prehospital emergency care were compared with the French 2002 standards. Emergency care at the University Teaching Hospital (UTH) was compared with World Health Organization 2005 Essential Trauma Care guidelines. Predefined care items were categorized as conforming to the standards or not. An emergency call center with a dedicated dial–up number has been established in the region since January 2007. Compared with the standards, this center was not protected by any legislation and was run by interns only. The center was underutilized during triage to help transportation of severe trauma patients. At the prehospital care level, only 3 out of 15 ambulances were equipped with resuscitation equipment and were used rarely. Only one of the ambulance staff out of three was trained in required skills. At the UTH, emergency care equipment and staff was nearly adequate. This study identified several opportunities for improvement in organizing trauma care in Fez particularly at emergency call center and ambulance service. A quality assurance program would be useful to further identifying improvements in this system.

Burden and factors associated with highway work-zone crashes, on a section of the Karachi-Hala Road, Pakistan.

Objective To assess the burden and factors associated with highway work-zone (HWZ) crashes. Design Historical cohort. Setting Section of the Karachi–Hala Road, Pakistan (196 km). Data Police-reported crashes and traffic statistics from January 2006 to December 2008. Analysis Crash and death risk between the HWZ and other zones for a 50 km section were compared. Crash locations were described for a further 146 km section on which factors associated with HWZ crashes were assessed. Results HWZ crashes accounted for 15.0% of traffic crashes (N=180) and 30.8% of road fatalities (N=91) on the 196 km section. Rates were higher in the HWZ than other zones for crashes (rate ratio (RR)=2.35, 95% CI=1.17 to 4.70) and deaths (RR=4.70, 95% CI=2.11 to 10.46). Opposite-direction crashes (adjusted OR (aOR)=10.65, 95% CI=3.22 to 35.25) and traffic crashes involving pedestrians (aOR=6.03, 95% CI=1.39 to 26.20) and on wet surfaces (aOR=7.26, 95% CI=4.15 to 48.89) were significantly associated with the HWZ. Conclusion These results support the introduction of prevention measures such as strict traffic enforcement, traffic separation, improving pedestrian visibility, and hazard signage at HWZs in Pakistan. The feasibility and effectiveness of these measures remains to be evaluated.

To Screen or Not to Screen: Reconciling Individual and Population Perspectives on Screening

Screening is the early detection of a latent disorder by a test to allow early intervention with the aim of improving prognosis. Individual and population perspectives on screening are perceived as opposing interests of patients and the population. In this article, we try to reconcile these perspectives. The individual perspective is based on the clinical experience of a better prognosis at early stages and patients with missed opportunities. In the population perspective, screening is based on a population-oriented, evidence-based model and addresses the acceptability and possible negative effects, including for people without the disorder. Known possible obstacles to a positive effect of screening include a short latent stage, lead time, overdiagnosis, lack of acceptability, poor performance of tests, and misclassification of outcome. Randomized trials of screening are challenging and need an adaptation of standards such as the Consolidated Standards of Reporting Trials (CONSORT). Simulating the effects of screening can allow the consideration of complex screening strategies and other options to help avoid biases related to treatment improvement and prevention success. Reconciling both perspectives is possible by considering that hypotheses underlying the former are prerequisites for the latter. From an evidence-based medicine and policy perspective, we suggest that recommending screening or prescribing a test is unethical if all possible obstacles are not documented by providing the best available evidence.

Introduction to the findings of the International Collaboration on Mild Traumatic Brain Injury Prognosis: what is a prognostic study?

Prognostic studies of mild traumatic brain injury (MTBI) can serve many purposes. First, they are used to describe paths and outcomes of patients with MTBI. Second, they provide information on which characteristics are associated with the occurrence of outcomes. Third, they provide insight into the causation of poor or favorable course of the disease. Finally, they can assess how differences in the probability of outcomes can help predict the course of patients. In this article, we summarize methodologic principles used by the International Collaboration on MTBI Prognosis to appraise the prognostic literature. Differentiating prognostic factors (causally linked with outcome), prognostic markers (associated but not causally), and predictors is important to guide interventions, public health policy, and research. Ideally, prognostic studies need a clear statement of the type of question (hypothesis-generating descriptive, exploration of possible prognostic variables, confirmatory modeling of prognosis); a cohort study design with standardized follow-up of a representative population of patients with MTBI; a standardized data collection using reliable and accurate tools to capture clinically, biologically, psychologically, or socially relevant variables and outcomes; and an analysis of data based on survival methods. Interpretation of prognostic studies should consider biases related to differential inclusion of nonrepresentative samples of patients, poor measurements of outcomes, and poor control for confounders. Transferring prognostic results into clinical practice should be based on estimates of the predictive performance of models and on a demonstration that patient outcomes can be improved by the use of prediction rules.