Six years of comprehensive, clinical, performance-based assessment using standardized patients at the Southern Illinois University School of Medicine.

By the end of 1990-91, the Southern Illinois University School of Medicine had had six years of experience with comprehensive, performance-based examinations of senior medical students' levels of clinical competence; this report assesses the psychometric aspects of the six examinations given during that period. The examinations were aimed at determining the students' readiness for postgraduate training. Compared with other clinical performance-based assessments that use standardized patients (SPs), these examinations had two important and unique features: (1) the examinations assessed a comprehensive range of clinical skills and reasoning; and (2) they approximated the challenges of real clinical practice wherein a practitioner's skills need to be orchestrated and prioritized in order to meet the challenges of the case encountered. Each year, the performance-based assessment given was an intensive clinical examination requiring each student to work up 13 to 18 SP problems over a three-day period. To administer an examination to an entire class of students took three weeks. Because all students after the first year of administration (1986) were required to pass these examinations, the fairness of test design and scoring and the setting of performance standards for the examinations became important issues for the faculty. The results, accumulated over six years and based on a total of 6,804 student-patient encounters involving 405 students, indicate that this kind of clinical performance-based examination can discriminate a wide range of students' clinical performances. The results provide evidence for the examinations' test security, content validity, construct validity, and reliability.     

Sodium bicarbonate versus THAM in ICU patients with mild metabolic acidosis

BACKGROUND: Sodium bicarbonate is despite its side effects, considered the standard alkali therapy in metabolic acidosis. THAM is an alternative alkalizing agent; however, there are limited data on the use of THAM in metabolic acidosis. The aim of this study was to compare the efficacy and adverse effects of a single dose of sodium bicarbonate and THAM in intensive care unit (ICU) patients with mild metabolic acidosis. METHODS: 18 adult ICU patients with mild metabolic acidosis (serum bicarbonate < 20 mmol/L) were randomized to a single dose of either sodium bicarbonate or THAM, administered over a 1-hour period, and titrated to buffer the excess of acid load. RESULTS: Sodium bicarbonate and THAM had equivalent alkalinizing effect during the infusion period. This was still present 4 hours after start of infusion of sodium bicarbonate, and until 3 hours after start of infusion of THAM. Serum potassium levels decreased after sodium bicarbonate infusion, and remained unchanged after THAM. After sodium bicarbonate, sodium increased, and after THAM, serum sodium decreased. CONCLUSIONS: Sodium bicarbonate and THAM had a similar alkalinizing effect in patients with mild metabolic acidosis; however, the effect of sodium bicarbonate was longer lasting. Sodium bicarbonate did decrease serum potassium, and THAM did not; THAM is therefore not recommended in patient with hyperkalemia. As sodium bicarbonate leads to an increase of serum sodium and THAM to a decrease, THAM may be the alkalinizing agent of choice in patients with hypernatremia. Similarly, because sodium bicarbonate increases PaCO2 and THAM may even decrease PaCO2, sodium bicarbonate is contraindicated and THAM preferred in patients with mixed acidosis with high PaCO2 levels.     

Cannabis use predicts future psychotic symptoms, and vice versa

AIMS: To assess if cannabis use is a risk factor for future psychotic symptoms, and vice versa, in adolescents and young adults from the general population. DESIGN: Cohort study. SETTING/PARTICIPANTS: 'Zuid Holland' study, a 14-year follow-up study of 1580 initially 4-16-year-olds who were drawn randomly from the Dutch general population. Because cannabis use is generally condoned in the Netherlands, false-negative reports of cannabis use may occur less frequently than in countries with stricter drug policies, which supports the value of the present study. MEASUREMENTS: Life-time cannabis use and psychotic symptoms, assessed with the Composite International Diagnostic Interview (CIDI). FINDINGS: Cannabis use, in individuals who did not have psychotic symptoms before they began using cannabis, predicted future psychotic symptoms (hazard ratio = 2.81; 95% confidence interval = 1.79-4.43). However, psychotic symptoms in those who had never used cannabis before the onset of psychotic symptoms also predicted future cannabis use (hazard ratio = 1.70; 95% confidence interval = 1.13-2.57). CONCLUSIONS: The results imply either a common vulnerability with varying order of onset or a bi-directional causal relationship between cannabis use and psychosis. More research on patterns and timings of these relationships is needed to narrow down the possibilities.     

Cannabis--psychosis pathway independent of other types of psychopathology

AIMS: To investigate if associations between cannabis use and psychotic symptoms occur independently, or occur as a consequence of previous-other types of-psychopathology. METHODS: A 14-year follow-up study of 1580 initially 4- to 16-year-olds who were drawn randomly from the Dutch general population was conducted. At initial assessment, psychopathology was assessed with the Child Behavior Checklist. Across the 14-year follow-up period, cannabis use and psychotic symptoms were assessed with the Composite International Diagnostic Interview (CIDI). Because cannabis use is generally condoned in The Netherlands, false-negative reports of cannabis use may occur less frequently than in countries with stricter drug policies, which supports the value of the present study. RESULTS: Survival analyses indicated that the association between cannabis use and psychotic symptoms occurred independently of initial CBCL scores. CONCLUSIONS: The link between cannabis use and psychotic symptoms is specific, and does not depend on the earlier presence of other types of psychopathology. This indicates that research aimed at unraveling mechanisms that are responsible for this specific association is useful. Further, given the fact that cannabis use seemed to be a specific risk factor for future psychotic symptoms, prevention aimed against cannabis use may prohibit the onset of psychotic symptoms in vulnerable individuals.     

Determinants of salivary cortisol levels in 10-12 year old children; a population-based study of individual differences

The hypothalamic-pituitary-adrenal (HPA)-axis is a central component of the body's neuroendocrine response to stress. Its major end-product cortisol has profound effects on mood and behavior. Although it has often been suggested, it remains unknown whether differences in HPA-axis physiology are part of an individual's vulnerability to psychopathology, and constitute a causal factor in its development. In order to study the contribution of HPA-axis physiology to the development of psychopathology, we measured HPA-axis physiology in a community-cohort of 1768 10-12 year-old children. The aims of the here presented study were twofold: (1) to obtain data on HPA-axis function in a large cohort of pre- and early-adolescent children, both in terms of total hormonal output and in terms of the dynamics of cortisol secretion (by means of the cortisol awakening response); and (2) to study potential confounders of the cortisol-psychopathology relationship in this age group, such as season of sampling, age, gender, pubertal development, perinatal variables and BMI. We found a wide interindividual variability in HPA-axis function. An increase in cortisol in the first 30 min after awakening was present in 70.7% of children, but the increase appears lower in children than in adults. In addition, this study suggests that season of sampling and gender may act as potential confounders in the cortisol-psychopathology relationship. We will follow these children longitudinally for the development of psychopathology in the period from childhood into adulthood. This period covers adolescence, which is a critical time for the appearance and development of psychiatric disorders.     

Psychiatric disorders in young adult intercountry adoptees: an epidemiological study

OBJECTIVE: The prevalences of psychiatric disorders in young adult intercountry adoptees and nonadopted young adults from the general population were compared. METHOD: In the Netherlands, a total of 1,484 young adult intercountry adoptees (72.5% of the original sample at age 10-15 years) and 695 nonadopted subjects (78.1% of the original sample) of comparable age from the general population were interviewed by using a standardized psychiatric interview generating DSM-IV diagnoses. RESULTS: The adopted young adults were 1.52 times as likely to meet the criteria for an anxiety disorder as the nonadopted young adults; the 95% confidence interval (CI) was 1.15-2.00. The adoptees were 2.05 (95% CI=1.32-3.17) times as likely to meet the criteria for substance abuse or dependence. The adopted men were 3.76 (95% CI=1.69-8.37) times as likely to have a mood disorder as nonadopted men, while for women there was no significant difference between adoptees and nonadoptees. No significant difference for the diagnosis of disruptive disorder was found. For all diagnoses together, adoptees with low and middle parental socioeconomic status in childhood did not differ from the comparison subjects, while adoptees with high parental socioeconomic status were 2.17 times (95% CI=1.50-3.13) as likely to meet the criteria for a disorder as nonadoptees with high parental socioeconomic status. CONCLUSIONS: Intercountry adoptees run a higher risk of having severe mental health problems in adulthood than nonadoptees of the same age. The risk of later malfunctioning differs for different disorders and different groups of adoptees.