Factors influencing medical student attrition and their implications in a large multi-center randomized education trial.

Participant attrition may be a significant threat to the generalizability of the results of educational research studies if participants who do not persist in a study differ from those who do in ways that can affect the experimental outcomes. A multi-center trial of the efficacy of different computer-based instructional strategies gave us the opportunity to observe institutional and student factors linked to attrition from a study and the ways in which they altered the participation profile. The data is from a randomized controlled trial conducted at seven US medical schools investigating the educational impact of different instructional designs for computer-based learning modules for surgical clerks. All students undertaking their surgical clerkships at the participating schools were invited participate and those that consented were asked to complete five study measures during their surgery clerkship. Variations in study attrition rates were explored by institution and by participants' self-regulation, self-efficacy, perception of task value, and mastery goal orientation measured on entry to the study. Of the 1,363 invited participants 995 (73 %) consented to participate and provided baseline data. There was a significant drop in the rate of participation at each of the five study milestones with 902 (94 %) completing at least one of two module post-test, 799 (61 %) both module post-tests, 539 (36 %) the mid-rotation evaluation and 252 (25 %) the final evaluation. Attrition varied between institutions on survival analysis (p < 0.001). Small but statistically significant differences in self-regulation (p = 0.01), self-efficacy (p = 0.02) and task value (p = 0.04) were observed but not in mastery or performance goal orientation measures (p = NS). Study attrition was correlated with lower achievement on the National Board of Medical Examiners subject exam. The results of education trials should be interpreted with the understanding that students who persist may be somewhat more self-regulated, self-efficacious and higher achievers than their peers who drop out and as such do not represent the class as a whole.

Just enough, but not too much interactivity leads to better clinical skills performance after a computer assisted learning module.

BACKGROUND: Well-designed computer-assisted instruction (CAI) can potentially transform medical education. Yet little is known about whether specific design features such as direct manipulation of the content yield meaningful gains in clinical learning. We designed three versions of a multimedia module on the abdominal exam incorporating different types of interactivity. METHODS: As part of their physical diagnosis course, 162 second-year medical students were randomly assigned (1:1:1) to Watch, Click or Drag versions of the abdominal exam module. First, students' prior knowledge, spatial ability, and prior experience with abdominal exams were assessed. After using the module, students took a posttest; demonstrated the abdominal exam on a standardized patient; and wrote structured notes of their findings. RESULTS: Data from 143 students were analyzed. Baseline measures showed no differences among groups regarding prior knowledge, experience, or spatial ability. Overall there was no difference in knowledge across groups. However, physical exam scores were significantly higher for students in the Click group. CONCLUSIONS: A mid-range level of behavioral interactivity was associated with small to moderate improvements in performance of clinical skills. These improvements were likely mediated by enhanced engagement with the material, within the bounds of learners' cognitive capacity. These findings have implications for the design of CAI materials to teach procedural skills.

Cerebral hypoperfusion yields capillary damage in the hippocampal CA1 area that correlates with spatial memory impairment.

The impact of chronic cerebral hypoperfusion on cognitive function and cerebral capillary morphology in the hippocampus was examined. Young adult Wistar rats were subjected to permanent ligation of both common carotid arteries (two-vessel occlusion). One month after vascular occlusion, a small but non-significant impairment in the acquisition of spatial information was registered compared with sham-operated controls. Two months after surgery, the occluded animals displayed an impaired performance throughout the training period. One year after surgery, the acquisition curves demonstrated a significant attenuation of the learning rate in the occluded rats group, whereas no significant differences in long-term retention were observed. Thus, chronic hypoperfusion induced by two-vessel occlusion gave rise to impairment of spatial memory. Following behavioural testing, the rats were killed at the age of 17 months, and capillaries in the CA1 and dentate gyrus were examined using transmission electron microscopy. Typical age-related capillary abnormalities such as degenerative pericytes and thickened basement membranes (with or without fibrosis) were detected in the hippocampus of sham animals. In occluded rats, the occurrence of capillaries displaying such abnormalities almost doubled in the CA1 region, but was similar in the dentate gyrus, compared with sham controls. A highly significant correlation was found between the last Morris maze performance and the percentage of capillaries with deposits in the basement membrane in the hippocampal CA1 area of occluded rats, which was not present in the sham animals. We conclude that a long-term hypoperfusion accelerated the development of age-related ultrastructural aberrations of capillaries in the hippocampal CA1 area, but not in the dentate gyrus. Thus, not only neurons, but also capillaries in the hippocampal CA1 area are sensitive to an impaired microcirculation. Moreover, the cognitive performance of hypoperfused rats correlated closely with the condition of the capillaries in the CA1 area, suggesting that capillary integrity is one of the important determinants of brain function in conditions that compromise cerebral microcirculation.

The effect of methylphenidate on the cognitive and personality functioning of ADHD children.

Twenty Israeli children diagnosed as having Attention Deficit Hyperactivity Disorder (ADHD) participated in the study. The study used a double-blind, cross-over, placebo-control design, in which each child received a three-week treatment of methylphenidate (MPH), and a three-week treatment with a placebo. Their teachers completed the Conners' Teacher Rating Scale (CTRS) along with ratings of other variables prior to the beginning of the study and during the two treatment periods. The subjects were tested on a specially designed battery of both cognitive and personality tests at the end of each treatment period. The results showed significant differences between ratings of children's behavior in pretest and subsequent placebo and MPH treatment periods. Comparison of the MPH and placebo treatment revealed no differences in any of the measures assessing cognitive ability and personality characteristics.

Personality assessment of children with attention deficit hyperactivity disorder.

The present research was designed to assess several potentially important factors in the personality structure of a sample of children with attention deficit hyperactive disorder (ADHD) as compared to normal control children. Three questionnaires were administered to a group of 28 ADHD boys and to a control group of 83 boys: (1) The Locus of Control Scale for Children; (2) The Revised Children's Manifest Anxiety Scale; and (3) The Persistence Scale for Children. Results showed that the ADHD children had significantly higher external locus of control, were significantly less persistent, and reported an elevated level of "concentration/social worry" (an anxiety subscale). Such findings can help to clarify both the personality structure and the coping styles of the ADHD child.