Formative Assessment of Diagnostic Testing in Family Medicine with Comprehensive MCQ Followed by Certainty-Based Mark.

INTRODUCTION: The choice of diagnostic tests in front of a given clinical case is a major part of medical reasoning. Failure to prescribe the right test can lead to serious diagnostic errors. Furthermore, unnecessary medical tests are a waste of money and could possibly generate injuries to patients, especially in family medicine. METHODS: In an effort to improve the training of our students to the choice of laboratory and imaging studies, we implemented a specific multiple-choice questions (MCQ), called comprehensive MCQ (cMCQ), with a fixed and high number of options matching various basic medical tests, followed by a certainty-based mark (CBM). This tool was used in the assessment of diagnostic test choice in various clinical cases of general practice in 456 sixth-year medical students. RESULTS: The scores were significantly correlated with the traditional exams (standard MCQ), with matched themes. The proportion of "cMCQ/CBM score" variance explained by "standard MCQ score" was 21.3%. The cMCQ placed students in a situation closer to practice reality than standard MCQ. In addition to its usefulness as an assessment tool, those tests had a formative value and allowed students to work on their ability to measure their doubt/certainty in order to develop a reflexive approach, required for their future professional practice. CONCLUSION: cMCQ followed by CBM is a feasible and reliable evaluation method for the assessment of diagnostic testing.

Three-Dimensional Printing Model Enhances Craniofacial Trauma Teaching by Improving Morphologic and Biomechanical Understanding: A Randomized Controlled Study.

BACKGROUND: Teaching about craniofacial traumas is challenging given the complexity of the craniofacial anatomy and the necessity for good spatial representation skills. To solve these problems, three-dimensional printing seems to be an appropriate educative material. In this study, the authors conducted a randomized controlled trial. The authors' main objective was to compare the performance of the undergraduate medical students in an examination based on the teaching support: three-dimensionally printed models versus two-dimensional pictures. METHODS: All participants were randomly assigned to one of two groups using a random number table: the three-dimensionally-printed support group (three-dimensional group) or the two-dimensionally-displayed support group (two-dimensional group). All participants completed a multiple-choice question evaluation questionnaire on facial traumatology (first, a zygomatic bone fracture; then, a double mandible fracture). Sex and potential confounding factors were evaluated. RESULTS: Four hundred thirty-two fifth-year undergraduate medical students were enrolled in this study. Two hundred six students were allocated to the three-dimensional group, and 226 were allocated to the two-dimensional group. The three-dimensionally printed model was considered to be a better teaching material compared with two-dimensional support. The global mean score was 2.36 in the three-dimensional group versus 1.99 in the two-dimensional group (p = 0.008). Regarding teaching of biomechanical aspects, three-dimensionally-printed models provide better understanding (p = 0.015). Participants in both groups exhibited similar previous student educational achievements and visuospatial skills. CONCLUSIONS: This prospective, randomized, controlled educational trial demonstrated that incorporation of three-dimensionally-printed models improves medical students' understanding. This trial reinforces previous studies highlighting academic benefits in using three-dimensionally-printed models mostly in the field of understanding complex structures.

Automated age-at-death estimation by cementochronology: Essential application or additional complication?

It has been repeatedly acknowledged that age-at-death estimation based on dental cementum represents a partial and time-consuming method that hinders adoption of this histological approach. User-friendly micrograph analysis represents a growing request of cementochronology. This article evaluates the feasibility of using a module to accurately quantify cementum deposits and compares the module's performance to that of a human expert. On a dental collection (n = 200) of known-age individuals, precision and accuracy of estimates performed by a developed program (101 count/tooth; n = 20,200 counts) were compared to counts performed manually (5 counts/tooth; n = 975 counts). Reliability of the software and agreement between the two approaches were assessed by intraclass correlation coefficient and Bland Altman analysis. The automated module produced reliable and reproducible counts with a higher global precision than the human expert. Although the software is slightly more precise, it shows higher sensitivity to taphonomic damages and does not avoid the trajectory effect described for age-at-death estimation in adults. Likewise, for human counts, global accuracy is acceptable, but underestimations increase with age. The quantification of the agreement between the two approaches shows a minor bias, and 94% of individuals fall within the intervals of agreement. Automation gives an impression of objectivity even though the region of interest, profile position and parameters are defined manually. The automated system may represent a time-saving module that can allow an increase in sample size, which is particularly stimulating for population-based studies.

Medico-legal considerations for Morel-Lavallée lesions.

The Morel-Lavallée lesion is an infrequent traumatic lesion that the forensic physician may need to evaluate during examination of a victim. Using a review of the literature and an illustrative case, the objective of this paper is to discuss the medico-legal issues (accountability, functional recovery and healing times, and aftermath) associated with Morel-Lavallée lesions. We describe the case of a 24-year-old motorcycle driver who was hit by a car. Clinically, the right lumbar region had a large 16 × 15 cm ecchymosis with subcutaneous fluid swelling found by palpation. A body scan revealed a Morel-Lavallée lesion among other lesions. On day 7, its thickness was decreased by half. Morel-Lavallée lesions are specifically induced by shearing force with moderate-to-high kinetics in an anatomical area with an underlying fascia. The associated functional disability is globally moderate, but a large lesion or recurrences can extend the time needed to recover. Apart from some exceptions, care without any delay in diagnosis and treatment allows evolution of the lesion without functional consequences, but these lesions are frequently unnoticed in the initial phase.

Use of 3D printed models in student education of craniofacial traumas.

A low-cost 3D printed model has been introduced into the oral and maxillofacial surgery teaching program of undergraduate students to improve education and mechanical comprehension of craniofacial trauma. Steps of the 3D printed haptic model building process are listed. 3D printed models of facial fractures were obtained from Data Imaging and Communications in Medicine (DICOM) data. Computed Aided Design and Manufacturing (CAD-CAM) freeware was used to create new fractures on the standard tessellation language (STL) file. 3D printed haptic model appears to be an efficient low-cost support for craniofacial trauma education of undergraduate students.

Age at death estimation by cementochronology: Too precise to be true or too precise to be accurate?

OBJECTIVES: Cementochronology based on annual deposition of acellular cementum is acknowledged for its superior performance for estimating age-at-death but is also disregarded because of its suspicious effectiveness. This article aims to provide a standardized framework for the validation of the technique and to define and test cementochronology's performance and limitations. MATERIALS AND METHODS: To determine the boundaries of the cementum aging technique, we applied a certified protocol on a sample of 200 healthy canines from individuals of known age, sex, postmortem, and inhumation intervals from anthropological and anatomical collections. We scored readability and preservation of cementum and measured the agreement between estimates, i.e., the precision, and assessed the quality of the accordance between estimates and chronological age, i.e., the accuracy. To investigate the applicability on ancient material, 200 additional canines extracted from archeological assemblages were included. Accuracy and precision were analyzed for each age group in considering postmortem intervals and taphonomical conditions. RESULTS: A strong correlation was found between chronological age and estimates (r = .927; p = .000) but results reveal an association between readability of incremental lines and chronological age (p < .05) and a notable difference in both precision and accuracy between individuals under and over 50 years. Results also demonstrate that taphonomy can be a serious obstacle increasing imprecision by a factor of three. DISCUSSION: Improperly adopted, cementochronology can lead to precise but inaccurate estimations. If methodological, physiological, and taphonomical factors are taken into account, then, and only then, cementochronology will serve as a versatile and powerful tool for age-at-death estimation.

Accuracy of script concordance tests in fourth-year medical students.

OBJECTIVES: This investigation aimed to determine the validity of script concordance test (SCT), compared with clinical-case-related short-answer management problems (SAMP), in fourth-year medical students. METHODS: This retrospective study was conducted at the Medical School of Lille University. Cardiology and gynecology examinations both included 3 SCT and 2 clinical-case-related SAMP.  Final score did not include SCT results, and was out of 20 points. The passing score was ≥10/20. Wilcoxon and McNemar tests were used to compare quantitative and qualitative variables, respectively. Correlation between scores was also analyzed. RESULTS: A total of 519 and 521 students completed SAMP and SCT in cardiology and gynecology, respectively. Cardiology score was significantly higher in SCT than SAMP (mean ± SD 13.5±2.4 versus 11.4±2.6, Wilcoxon test, p<0.001). In gynecology, SCT score was significantly lower than SAMP score (10.8±2.6 versus 11.4±2.7, Wilcoxon test, p=0.001). SCT and SAMP scores were significantly correlated (p <0.05, Pearson's correlation). However, percentage of students with SCT score ≥ 10/20 was similar among those who passed or failed cardiology (327 of 359 (91%) vs 146 of 160 (91%), χ2=0.004, df =1, p=0.952), or gynecology (274 of 379 (65%) vs 84 of 142 (59%), χ2=1.614, df=1, p=0.204) SAMP test. Cronbach alpha coefficient was 0.31 and 0.92 for all SCT and SAMP, respectively. CONCLUSIONS:  Although significantly correlated, the scores obtained in SCT and SAMP were significantly different in fourth-year medical students. These findings suggest that SCT should not be used for summative purposes in fourth-year medical students.

Organ Procurement in Forensic Deaths: Specific Features of Nonheart-Beating Donors.

The need for organs has increased in the recent years, and this shortage will only worsen. In addition to the organs procured from brain-dead donors, a procedure for non-heart-beating donors was therefore developed. When deaths involve legal proceedings, the medical examiner makes the decision of whether or not to remove organs. To assist medical examiner in their decision-making, a number of forensic scientific societies aimed to develop recommendations, and legal adjustments were adopted. Nevertheless, these do present certain limits in special cases of procurement: Maastricht class I and II non-heart-beating donors. The peculiarity of this procedure stems from the urgency of the process. Compliance with temporal criteria would require that the deceased subject be removed from the crime scene even before the arrival of the authorities. This is extremely problematic legally and technically because forensic teams must collect evidence at crime scenes. Developments will have to be made to further minimize the restrictions on donations in forensic deaths.

Effects of the environment on bone mass: A human taphonomic study.

An experiment was designed using human ribs placed in different environments to document how moisture and temperature affect the bone mass according to the postmortem interval. The bones were defleshed, weighed and partially buried, with some ribs being left unburied as controls. The ribs were weighed daily, and the mass loss was monitored over a period of 90days. The results showed that significant differences in bone mass loss exist between environments, where the bone mass loss was significantly faster in an environment with low moisture content. This mass loss is thought to be primarily associated with the desiccation of the body and then for a greater part, with the atmospheric moisture content. However, the loss of bone mass can also be explained by early alterations in the organo-mineral matrix which were highlighted by Raman spectroscopy method.

The mechanism of the keyhole lesion reassessed: An experimental approach.

The initial description of the keyhole defect was detailed as a peculiar gunshot entrance wound in the cranial vault due to firearm discharge in a tangential path. This injury may be described in two parts: a rounded section with inner table beveling and a triangular section with outer table beveling. We report a case of a gunshot skull wound "keyhole" shaped, appeared to have been made perpendicularly to the bone. Performing an experimental study on cranial bones with shots made perpendicularly to the skull approved this hypothesis, and bone injuries were then architecturally characterised using high-resolution micro computed tomography. The singular link between the tangential gunshot path and the keyhole pattern has been refuted several times, and some authors have hypothesised that there is an important role for concentric fractures that occur far away from the initial impact point of the bullet. Micro computed tomography analysis of the bone showed these keyhole defect features with a particular high description. Then, the whole pattern has a spider-web effect, and these concentric fractures could explain the keyhole pattern even in a perpendicular gunshot path.

Organ procurement in forensic deaths: French developments.

Organ procurement and transplantation have grown steadily, and the need for organs will only rise in the future. Increasing the number of potential donors is therefore paramount. However, transplant coordination teams face refusals that can be linked to the contexts of the deaths, especially when they involve legal issues. In France, deaths involving legal proceedings are not uncommon (7-10%). In these cases, the prosecutor is immediately contacted, and makes the decision of whether to remove the involved organs. Refusals of this type represent 4% (approximately 30 cases per year) of obstacles to organ removals, and are governed by specific legislation. Thus, the prosecutor must arrange contact with a forensic pathologist and with the organ transplant teams to assemble all of the necessary elements for him to take the decision. To assist prosecutors in their decision making and to ensure them scientific rigour, the French Society of Forensic Medicine sought to develop a national recommendation to harmonise practices; it emerged in early 2013. The guideline makes practical recommendations, including among others: nominating local referents; writing regional protocols between judicial authorities, forensic pathologists and transplant teams; establishing terms for the forensic pathologist's intervention on the donor's body before and after a procurement. This recommendation by the French Society of Forensic Medicine aimed to combine two interests: addressing the shortage of organs, and fulfilling the requisites of a criminal investigation by standardising practices and encouraging communication.

Experimental study of Lucilia sericata (Diptera Calliphoridae) larval development on rat cadavers: Effects of climate and chemical contamination.

Household products such as bleach, gasoline or hydrochloric acid have been used to mask the presence of a cadaver or to prevent the colonization of insects. These types of chemicals affect insect development and alter the forensic entomology analysis. This study was designed to test the effects of six household products (bleach, mosquito repellent, perfume, caustic soda, insecticide and unleaded gasoline) on blowfly (Lucilia sericata, Diptera: Calliphoridae) larval development. Furthermore, the effects of climate (rain or dry conditions) on larval development were analyzed. For each replication, 100 first instars were placed on a rat cadaver on which one household product was spilled. We observed a decrease in the survival rates of the larvae but no significant effect on their development times or the adult size. The same trends were observed under rainy conditions. However, the rain altered the effects of some tested household products, especially gasoline. These results demonstrate for the first time the successful development of necrophagous larvae on chemically contaminated cadavers, and provide evidence for the range of possible effects to expect.

Specific patterns of canine scavenging in indoor settings.

Postmortem animal mutilations due to domestic dogs in isolated domestic deaths are taphonomic modifications regularly observed by forensic pathologists. They are rarely described in the literature; however, even though they present specific patterns. Through 41 cases, 10 at the forensic institute in Lille (France) and 31 at the New York City Office of Chief Medical Examiner (USA), plus 22 cases from the literature, specific locations and patterns of postmortem scavenging lesions are proposed. These lesions are mainly distributed in three locations: the face, especially the nose and the mouth (73.1%), the neck (43.1%), and the arm (shoulder/upper limb [29.2%], hand [26.8%]). We discuss the time span between death and scavenging, the consequences on identification, and comparison with outdoor settings. Outdoor scavenging lesions are mainly located on the trunk and limbs usually sparing the head, which strongly differs from indoor distribution and imply different animal motivations.

In vitro effects of household products on Calliphoridae larvae development: implication for forensic entomology.

Several parameters can delay the first arrival of flies on a corpse and the subsequent development of the larvae. This study focuses on the development of Lucilia sericata (Diptera: Calliphoridae) (Meigen, 1826) on household chemical-contaminated substrates. bleach, perfume, hydrochloric acid, caustic soda, insecticide, mosquito repellent, and gasoline in quantities consistent with an amount that could possibly be spilled on a corpse were mixed with beef liver to simulate contaminated fleshes. Larvae were bred at 25 °C on these media until emergence. Four developmental parameters were followed: survival rates, development times, sex ratios, and adult sizes. Hydrochloric acid, insecticide, and gasoline killed all larvae. In low quantities, caustic soda and mosquito repellent increased the development time and decreased the adult size. However, high quantities of these chemicals killed all larvae. Lastly, bleach and perfume did not affect the survival rate and barely impacted the development time or adult size. These results demonstrate common household products spilled on a corpse can strongly affect the development of Calliphoridae larvae. The effects of such products should be considered in forensic entomology cases.

[Performing autopsies of all sudden deaths: a public health prevention strategy]. / Pratiquer l'autopsie de toutes les morts subites : un moyen de prévention en santé publique.

INTRODUCTION: In France, the management of sudden death (including nion-forensic autopsies) among adults could be improved. Thee number of sudden deaths may require a change in practice to promote screening for hereditary diseases. The purpose of this study was to identify areas for improvement and to assess the prevalence of non-forensic autopsies. METHODS: A retrospective study (2005-2010) conducted at Lille University Hospital resulted in the selection of 174 non-forensic autopsies of adults who died suddenly. The criteria used were: the geographical origin of the bodies, indication, age, gender and the diagnosis ofdeath. RESULTS: The study found that the annual number of non-forensic autopsies was very low, with proportions ranging from 1.06 to 1.73 per 1,000 deaths in the case of hospital deaths and from 0 to 0.43 per 1,000 deaths in the case of non-hospital deaths. Only 11 non-forensic autopsies of people who died at home were recorded over the study period, including 4 heart disease-related deaths. Overall, the results indicate that sudden death autopsies are poorly managed. DISCUSSION: Non-forensic autopsies are in decline, particularly in the case of deaths outside hospital, despite the fact that they are a crucial consideration for screening among relatives of a person who died sud!denly. The findings suggest that there needs to be an improvement in practice, a fact made possible by recent legislative developlments in France. A number of initiatives have been successful arId give hope that, like the reference centers specializing in unexpected infant deaths, reference centers specializing in sudden de'aths, which allow for more systematic non-forensic autopsies ofadults who die suddenly, might be created.

Discontinuous foraging behavior of necrophagous Lucilia sericata (Meigen 1826) (Diptera Calliphoridae) larvae.

Larvae of the necrophagous Blowfly Lucilia sericata (Diptera Calliphoridae) live on vertebrate cadavers. Although continuously feeding was previously assumed for this species, we hypothesized that larvae do not feed constantly. According to this hypothesis, their crop should not always be full, which should be reflected in crop surfaces. We dissected and measured the crops of larvae of the same age and bred in the same conditions. Crop surfaces of 117 larvae just removed from the food ranged from 0 to 16.6 mm(2) (mean=5.325±2.84 mm(2)). The distribution of these crop surfaces indicates a continuous variation of satiation/feeding activity in the population. Starving experiments showed a quite long digestive process. After 90 min of starving, the decrease in crop surfaces became obvious, but 150 min were necessary to observe more than a half of the population with an empty crop (less than 2 mm(2)). No more differences were observed after 150, 180 and 240 min of starving. We finally used starved larvae to observe the kinetic of food absorption and the duration of the food-intake phase. Our results indicates that larvae can ingest faster than they digest. After 5 min spent in the food, 70% of the larvae had a crop surface larger or equal to 8 mm(2). We observed for the first time an over-feeding of the larvae, with high crop surfaces overrepresented compared to larvae never starved (control). Together, these results indicate that larvae do not feed continuously, and regulate their foraging behavior. We propose that the foraging behavior of the larvae creates a permanent movement inside the larval masses. This turnover/scramble competition may be linked to the larval-mass effect, i.e. the local temperature increase observed in large necrophagous larvae aggregates.

[Body's integumentary restoration after autopsy: legislative, technical and ethical issues]. / Restauration des corps après autopsies : aspects législatifs, techniques et éthiques.

In France, families of the deceased raised concerns as regards to the conditions of restoration of body. If scientists hospital autopsies are organized by the Bioethics Law of August 6, 2004, the forensic autopsies were so far not provided with such a legal framework. The legislator has proposed the creation of a new chapter in the Code of Criminal Procedure institutionalizing forensic activities. This legislative evolution allows the harmonization of practices; forensic pathologists must be involved in these changes by bringing their scientific expertise, notably through improving their autopsy techniques.

Skull wounds linked with blunt trauma (hammer example). A report of two depressed skull fractures--elements of biomechanical explanation.

The lesions of the skull following perforating traumas can create complex fractures. The blunt traumas can, according to the swiftness and the shape of the object used, create a depressed fracture. The authors describe through two clinical cases the lesional characteristic of the blunt traumas, perforating the skull using a hammer. In both cases the cranial lesions were very typical: they were geometrical, square shaped, of the same size than the tool (head and tip of the hammer). On the outer table of the skull, the edges of the wounds were sharp and regular. On the inner table, the edges of the wounds were beveled and irregular. The bony penetration in the depressed fracture results from a rupture of the outer table of the bone under tension, in periphery, by the bend of the bone to the impact (outbending) and then, from the inner table with comminuted bony fragmentation. Breeding on the fractures of the size and the shape of the blunt objects used is inconstant and differs, that it is the objects of flat surface or wide in opposition to those of small surface area. Fractures morphologies depend on one hand on these extrinsic factors and on the other hand, of intrinsic factors (structure of the bone). To identify them, we had previously conducted experimental work on cranial bone samples. The bone was submitted to a device for three-point bending. This work had shown properties of thickness and stiffness of the various areas of the vault. Our cases are consistent with these results and illustrate the variability of bone lesions according to region and mode of use of blunt weapons. Many studies have identified criteria for identification of the weapons and the assistance of digital and biomechanical models will be an invaluable contribution with this aim in the future.

[Publications of medical thesis defended in Lille school of medicine]. / Publications des thèses d'exercice soutenues à la faculté de médecine de Lille.

OBJECTIVE: The purpose of this study was to determine the future, in terms of scientific publication, of medical thesis (MT) defended in the Medical School of Lille 2 University (MSL2U) between January 1st, 2001 and December 31st, 2007. METHODS: The collection of MT published as a corresponding scientific article was realized from PubMed(®). For every corresponding article, we determined the journal Impact Factor (IF), the language of publication and the rank of the student and his MT director in the author list. Analyses were also realized according to the group of speciality of the TM. RESULTS: In all, 11.3% of the 2150 MT defended in the MSL2U were followed up by a scientific publication. The average IF was 2.32 with a median at 1.75 and extreme values from 0 to 14.78. Seventy percent of the articles were published in English. The rank of the student was placed before his MT director (2.06 vs. 3.15). The MT defended by students in the field of medical specialities presented the highest rate of publication (25.1%). The general medicine was the second speciality the most productive in term of number of published articles (n=49) after medical specialities (n=103). CONCLUSION: The MT director and the PhD students must be more motivated to publish their results. The value of 11.3% could be considered as weak but, because of a huge lack of references, it is impossible to compare our results to those of other French medical schools. It remains important to reform the objectives and the modalities of the writing of a MT: should we not have to turn to thesis called "on article"?