It has been suggested that the 'ideal' measure of reliability of an examination is obtained by test and retest using the one examination on the same group of students. However, because of practical and theoretical arguments, most reported reliabilities for multiple choice examinations in medicine are actually measures of internal consistency. While attempting to minimize the effects of potential interfering factors, we have undertaken a study of true test-retest reliability of multiple true-false type multiple choice questions in preclinical medical subjects. From three end-of-term examinations, 363 items (106 of 449 from term 1, 150 of 499 from term 2, and 107 of 492 from term 3) were repeated in the final examination (out of 999 total items). Between test and retest, there was little overall decrease in the percentage of items answered correctly and a decrease of only 3.4 in the percentage score after correction for guessing. However, there was an inverse relation between test-retest interval and decrease in performance. Between test and retest, performance decreased significantly on 33 items and increased significantly on 11 items. Test-retest correlation coefficients were 0.70 to 0.78 for items from the separate terms and 0.885 for all items that were retested. Thus, overall, these items had a very high degree of reliability, approximately the 0.9 which has been specified as the requirement for being able to distinguish between individuals.
The Phase I and Phase II undergraduate teaching programmes of the School of Medical Sciences were reviewed at the end of the 1985/86 academic year. It was found that deviations from the School's philosophy had crept into the implementation process. Modifications were therefore made in Phase I and Phase II programmes with a view to:--(i) reducing content, (ii) promoting integration, (iii) improving clinical examination skills of students, and (iv) providing more opportunities to students for self learning, reinforcement and application of knowledge. The number of assessment items in Phase I and the frequency of assessment in Phase II were also found to be inappropriate and so modifications in assessment were made to rectify this situation.
Intestinal permeability of 246 early primary schoolchildren at 2 schools (106 of whom were infected with intestinal helminths) was assessed by using the lactulose/mannitol differential absorption test. The ratio of the urinary recoveries of lactulose and mannitol was determined after oral administration of a standard solution of the 2 sugars. Assessment of intestinal permeability was repeated on 100 infected children after treatment and on a cohort of 68 uninfected children. Infected and uninfected groups were compared with respect to baseline lactulose/mannitol ratio (L/M1) and change in lactulose/mannitol ratio between assessments (delta L/M). The correlations between baseline intensity of infection and L/M1, and between fall in intensity and delta L/M, were evaluated. Based on a crude index of socioeconomic status, each child was assigned to one of 3 socioeconomic groups; all but 3 children belonged to either groups 2 or 3. Trichuris trichiura and Ascaris lumbricoides were the 2 predominant infections; the hookworm infection rate was relatively low. The results suggested that helminthiasis exerted only a marginal effect on intestinal permeability, the impact of which in children from lower socioeconomic backgrounds was negligible in comparison with the cumulative effects of other factors.
Stool examination of 249 early primary schoolchildren at 2 schools in north-eastern peninsular Malaysia revealed that 73 were infected with Ascaris lumbricoides, 103 with Trichuris trichiura, and 18 with hookworms. Infected children were treated with a single dose of 400 mg of albendazole. The school attendance records during a 60 d period before treatment and 2 consecutive 60 d periods after treatment were examined. The absenteeism rate did not improve more among infected children after treatment than it did among the uninfected control children. The correlation between worm intensity and the number of lost school-days was poor. There was no evidence that intestinal helminthiasis caused school absenteeism among this group of children.
Stool examination, height and weight measurements were undertaken on 249 early primary school children at two schools in North-eastern Peninsular Malaysia. Helminth infected children were treated and follow-up anthropometric measurements and stool examination undertaken on all (n = 100) children at one of the schools 16 months later; to observe the relationship between acquisition of infection and growth. Baseline Ascaris prevalence rates at the two schools were 16.0% (23/144) and 47.6% (50/105) respectively whilst Trichuris rates were 33.3% (48/144) and 52.4% (55/105). Hookworm infection was uncommon. There was no difference in weight or height for age between infected and uninfected children at any time. Acquisition of worm infection over the initial 16 month follow-up period was not associated with significant decreases in growth rates. However the small subsets of children with heavy Ascaris infection were consistently lighter and shorter at all evaluation times. They also gained significantly less weight and tended to have reduced linear growth rates between measurements. Further interventional studies are required to determine if this association is one of cause and effect or largely incidental.