Cumulative versus end-of-course assessment: effects on self-study time and test performance.

CONTEXT: Students tend to postpone preparation for a test until the test is imminent, which raises various risks associated with 'cramming' behaviours, including that for suboptimal learning. Cumulative assessment utilises spaced testing to stimulate students to study more frequently and to prevent procrastination. This randomised controlled study investigated how cumulative assessment affects time spent on self-study and test performance compared with end-of-course assessment. METHODS: A total of 78 undergraduate medical students in a Year 2 pre-clinical course were randomly assigned to either of two conditions. Students in the cumulative assessment condition were assessed in weeks 4, 8 and 10. Students in the end-of-course assessment condition were assessed in week 10 only. Each week, students reported the number of hours they spent on self-study. RESULTS: Students in the cumulative assessment condition (n = 25) spent significantly more time on self-study than students in the end-of-course assessment condition (n = 37) in all weeks of the course except weeks 5, 9 and 10. Overall, the cumulative assessment group spent 69 hours more on self-study during the course than did the control group, although the control group spent 7 hours more in studying during the final week of the course than did the cumulative assessment group. Students in the cumulative assessment condition scored slightly higher on questions concerning the content of the last part of the course. CONCLUSIONS: Cumulative assessment encourages students to distribute their learning activities over a course, which leaves them more opportunity to study the content of the last part of the course prior to the final examination. There was no evidence for a short-term effect of cumulative assessment on overall knowledge gain. We hypothesise that larger positive effects might be found if retention were to be measured in the long term.

Using a genetic, observational study as a strategy to estimate the potential cost-effectiveness of pharmacological CCR5 blockade in dialysis patients.

BACKGROUND AND OBJECTIVE: Randomized clinical trials are expensive and time consuming. Therefore, strategies are needed to prioritise tracks for drug development. Genetic association studies may provide such a strategy by considering the differences between genotypes as a proxy for a natural, lifelong, randomized at conception, clinical trial. Previously an association with better survival was found in dialysis patients with systemic inflammation carrying a deletion variant of the CC-chemokine receptor 5 (CCR5). We hypothesized that in an analogous manner, pharmacological CCR5 blockade could protect against inflammation-driven mortality and estimated if such a treatment would be cost-effective. METHODS: A genetic screen and treat strategy was modelled using a decision-analytic Markov model, in which patients were screened for the CCR5 deletion 32 polymorphism and those with the wild type and systemic inflammation were treated with pharmacological CCR5 blockers. Kidney transplantation and mortality rates were calculated using patient level data. Extensive sensitivity analyses were performed. RESULTS: The cost-effectiveness of the genetic screen and treat strategy was &OV0556;18 557 per life year gained and &OV0556;21 896 per quality-adjusted life years gained. Concordance between the genetic association and pharmacological effectiveness was a main driver of cost-effectiveness. Sensitivity analyses showed that even a modest effectiveness of pharmacological CCR5 blockade would result in a treatment strategy that is good value for money. CONCLUSION: Pharmacological blockade of the CCR5 receptor in inflamed dialysis patients can be incorporated in a potentially cost-effective screen and treat programme. These findings provide formal rationale for clinical studies. This study illustrates the potential of genetic association studies for drug development, as a source of Mendelian randomized evidence from an observational setting.