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M de Haan

Publications and source records attributed to M de Haan.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of a pharmacotherapy context-learning programme for preclinical medical students.

AIM: To evaluate a context-learning pharmacotherapy programme for approximately 750 2nd, 3rd and 4th year preclinical medical students with respect to mastering cognitive pharmacotherapeutic skills, i.e. choosing a (drug) treatment and determining patient information. METHODS: The context-learning pharmacotherapy programme consists of weekly organized role play sessions in the form of consulting hours. Fourth year students sit for a therapeutic Objective Structured Clinical Examination (OSCE) in the form of consulting hours at the outpatient clinic. Sixty-one 2nd, 74 3rd and 49 4th year medical students who attended the role play sessions and the OSCE were randomly selected. Their performances were assessed by clinical examiners and clinical experts and compared with a reference group of 6th year graduated students. Additionally, the scores of a questionnaire on study load and appreciation were collected. RESULTS: The level of the pharmacotherapeutic skills of the 4th year students who followed the pharmacotherapy context-learning programme was not far below that of 6th year graduates who had finished their clinical clerkships, but had not followed the pharmacotherapy programme. The time spent on the programme was about 1% of the total study load per year. The students appreciated the role play sessions and OSCE by around 80% and 99% of the maximum possible scores. CONCLUSIONS: Preclinical pharmacotherapy context learning has a modest but positive effect on learning cognitive pharmacotherapeutic skills, i.e. choosing a drug treatment and determining patient information. This effect has been obtained with role play sessions, a suboptimal form of context learning, with a minimal study load and a high appreciation by students.

Adult↗
PubMed2006

Is high-spatial frequency information used in the early stages of face detection?

The present study examined the role of high-spatial frequency information in early face processing, as indexed by the N170 face-sensitive ERP component. Participants detected 4 versions of famous faces, including full spectrum faces, and bandpass filtered faces containing predominantly high-spatial frequencies, low-spatial frequencies or both. The power spectra of all stimuli were balanced by superimposing the faces onto a visual noise background that included the spatial frequency information that was missing in filtered faces, e.g., high-spatial frequency faces were presented on a high- and low-spatial frequency background. An additional condition comprising of filtered visual noise only was also created to ensure that any observed effects were related to the processing of faces and not simply due to variations between spatial frequency information. Both behavioral and electrophysiological results replicated previous findings of a low-spatial frequency advantage for face processing. However, our results also show that faces containing both high and low-spatial frequency information are detected faster and more accurately than faces containing predominantly low-spatial frequencies. Furthermore, this advantage occurred with an enhanced amplitude of the N170. Together, these findings refute the suggestion that high-spatial frequencies are redundant in face perception.

Adult↗
PubMed2006

Curriculum development in pharmacotherapy: testing the ability of preclinical medical students to learn therapeutic problem solving in a randomized controlled trial.

AIMS: To determine whether preclinical medical students are able to learn therapeutic problem solving simultaneously with gaining knowledge of pharmacology. METHODS: A randomized controlled pre/post-test study among 85 3rd year preclinical medical students from two medical faculties in Amsterdam. In addition to the normal curriculum, the study group followed a course, which was a copy of the obligatory training in cognitive therapeutic skills for 5th year students who had gained knowledge first, followed by applying the knowledge. Before, immediately after and 9 months after the training both the study group and a control group took a test (T0, T1, T2). The level of knowledge and cognitive therapeutic skills were assessed. As a reference, 38 5th year students also took the tests. RESULTS: On T0 the levels of cognitive therapeutic skills of the study and control groups were similar (26.7% and 27.4% of the required level for graduation, respectively). On T1 and T2, the study group scored significantly higher compared with the control group: 46.0/36.7% and 41.3/36.3%, respectively (P<0.05). In comparison with T0, the scores of the study group on T1 increased significantly and showed no significant decline on T2. There were no differences between the groups with respect to the level of knowledge in any of the three tests. The level of cognitive therapeutic skills in the 5th year reference group increased slightly but not significantly from 40.3% to 44.5% after the training; the level of knowledge increased significantly from 48.8% to 68.0%. CONCLUSIONS: Preclinical medical students are able to learn cognitive therapeutic skills simultaneously with gaining knowledge of pharmacology.

Adult↗
PubMed2005

[Reasons for non-response of elderly Turkish, Moroccan and Dutch general practice patients on a postal depression screening].

BACKGROUND: Depression screening can improve identification and subsequent treatment of depression in general practice. Response of Turkish and Moroccan elderly is unknown. OBJECTIVES: (1) To assess the response of elderly Turkish and Moroccan general practice patients on a postal depression screening. (2) To trace reasons for non-response. METHOD: At 14 different primary care centres, elderly (55+) were screened with GDS-15. Turkish and Moroccan elderly were telephonically and house-to-house approached for tracing the reasons for non-response. RESULTS: Response rate Dutch elderly (n=6060; 62%), Turks (n= 39; 31%) and Moroccans (n=117; 34%). Most important reason for non-response among Turkish elderly was "temporary other place of staying" (Turkey). Among Moroccans it was "illiteracy". CONCLUSION: Response is very low by elderly migrants compared to Dutch elderly. The reasons for non-response implicate that other means to approach migrants' sub-populations should be sought.

Aged↗
PubMed2003

[The importance of equivalence trials in showing the usefulness of treatments].

There are different kinds of randomised controlled trials: trials in which the superiority of a treatment can be demonstrated (superiority trials) and trials in which the equal efficacy of two treatments can be shown (equivalence trials). The main reason for performing an equivalence trial is that for many diseases and disorders an effective treatment already exists. Equivalence trials are appropriate when a new treatment offers some advantages over an existing treatment (less cost, greater safety, improved convenience or freedom of choice for the patient), in addition to the expected equal therapeutic effectiveness. The design of equivalence trials is to a large extent comparable to that of superiority trials, but there are some methodological differences. In equivalence trials, the null hypothesis and alternative hypothesis are interchanged, compared to superiority trials. In equivalence trials, an equivalence margin is defined for the different treatments. Clinical professionals decide on the equivalence margin beforehand on the basis of the clinical relevance. To demonstrate equivalence, the confidence interval of the difference between two treatments must lie completely within the equivalence margin. In equivalence trials, there are usually more patients needed: the smaller the equivalence margin, the more patients are needed. In equivalence trials, both per-protocol analyses and intention-to-treat analyses should be used to prove the equal therapeutic effectiveness of the treatments under study.

Clinical Trials as Topic↗
PubMed2003

Investigating individual differences in brain abnormalities in autism.

Autism is a psychiatric syndrome characterized by impairments in three domains: social interaction, communication, and restricted and repetitive behaviours and interests. Recent findings implicate the amygdala in the neurobiology of autism. In this paper, we report the results of a series of novel experimental investigations focusing on the structure and function of the amygdala in a group of children with autism. The first section attempts to determine if abnormality of the amygdala can be identified in an individual using magnetic resonance imaging in vivo. Using single-case voxel-based morphometric analyses, abnormality in the amygdala was detected in half the children with autism. Abnormalities in other regions were also found. In the second section, emotional modulation of the startle response was investigated in the group of autistic children. Surprisingly, there were no significant differences between the patterns of emotional modulation of the startle response in the autistic group compared with the controls.

Adolescent↗
PubMed2003

Cortical specialisation for face processing: face-sensitive event-related potential components in 3- and 12-month-old infants.

The adult N170 is considered to be an electrophysiological marker of specialised mechanisms for face processing, but little is known about its developmental origin. Previous work has identified two face-sensitive infant ERP components (N290 and P400) (J. Cog. Neurosci. 14 (2002), 199). In the present study, we assessed the specificity (to upright human faces) of these infant components at 3 and 12 months. At 12 months the degree of specificity observed in both components was similar to that seen in the adult N170. In contrast, at 3 months of age the N290 and P400 did not show the same level of specificity for human faces as that observed at 12 months. Our findings suggest that (1) both face-sensitive components increase in their specificity for upright human faces during development, and (2) the adult N170 is not preceded by a single developmental precursor, but rather emerges as a consequence of the integration of two functionally and morphologically distinct components (N290 and P400).

Animals↗
PubMed2003

The influence of co-morbidity on health-related quality of life in asthma and COPD patients.

This study examines the association between somatic co-morbidity and both general and disease-specific health-related quality of life (HRQoL) in patients with asthma and chronic obstructive pulmonary disease (COPD). A cross-sectional analysis was done among 161 COPD patients and 395 asthma patients, aged 40-75 years, recruited from general practice. In the total study population, 47% had no, 32% had one, and 21% had two or more somatic co-morbid conditions, with no significant differences between asthma and COPD patients. Co-morbidity appeared to be associated with poor disease-specific HRQoL in asthma [odds ratio (OR) = 2.08 (1.37-3.18)] and with poor general HRQoL in asthma [OR = 2.96 (1.93-4.53)] and COPD [1.81 (0.91-3.60)] patients. Poorest HRQoL was found in patients with more than one co-morbid condition. Cardiac disease and hypertension were associated with poor disease-specific HRQoL in asthma. Of all co-morbid conditions, musculoskeletal disorders were most strongly associated with poor general HRQoL. Cardiac disease was found to be associated with general and disease-specific HRQoL in asthma but not in COPD. In studies on patients with asthma or COPD aged 40-75 years, co-morbidity should be treated as a determinant of HRQoL.

Adult↗
PubMed2003

Switching from NSAIDs to paracetamol: a series of n of 1 trials for individual patients with osteoarthritis.

OBJECTIVES: To investigate for individual patients who have been using NSAIDs regularly, whether paracetamol is as effective as non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of pain and disability related to osteoarthritis of the hip or knee. METHODS: A series of n of 1 trials were conducted in general practices in Amsterdam and the surrounding area. Each patient was his or her own control and received five pairs of treatments comprising two weeks of an NSAID and two weeks of paracetamol. For each pair, the order of treatments was randomised. Outcome measures were severity of individual main complaints, intensity of pain, satisfaction with drugs, function test, and side effects. RESULTS: Thirteen patients were selected. Six patients did not complete the study. For five patients completing the study little or no difference was found between NSAIDs and paracetamol, for one patient the results favoured the NSAID, and for one patient there was no association between outcome and type of drug. It was recommended that six patients changed to paracetamol; the others continued with NSAIDs. Three months after the end of the study, four of the six patients for whom paracetamol had been recommended were taking NSAIDs for practical reasons or perceived lack of efficacy. CONCLUSION: The results of the n of 1 trials varied across patients. n of 1 trials can be used to investigate which treatment is best for any specific person, thus avoiding unnecessary prolonged treatment with NSAIDs. However, practical reasons may cause patients to switch from NSAIDs to paracetamol or not.

Acetaminophen↗
PubMed2002

Endocrine stress response in jugular-vein cannulated rats upon multiple exposure to either diethyl-ether, halothane/O2/N2O or sham anaesthesia.

The main objective of this study was to assess the endocrine stress response to multiple anaesthesia followed by sham anaesthesia in order to detect any memory effects. For this purpose, jugular-vein cannulated rats were subjected to either sham, diethyl-ether or halothane/O2/N2O anaesthesia, and their plasma ACTH, corticosterone, glucose, adrenaline and noradrenaline levels measured. The study had three separate experiments, each consisting of a control and treatment group. In two experiments, the rats were exposed to high or low concentrations (40-15%) of diethyl ether, using either a jar containing cotton soaked in diethyl ether or a vaporizer. In the third experiment, rats were exposed to halothane/O2/N2O. Control animals underwent sham anaesthesia. Blood samples were taken 6 min before and at 5, 15 and 55 min after starting the exposure (t = 0 min). For each variable, the dt5 (level at t = 5 min minus that at t = -6 min) and the cumulative levels over the one-hour period as determined by the area under the curve (AUC) were calculated. Further, the peak levels (Cmax) were determined. The mean time needed to induce anaesthesia was 68, 121 and 55 s for exposure to high and low concentrations of diethyl ether and to halothane/O2/N2O, respectively. Increased noradrenaline and adrenaline dt5 levels were observed only after the first exposure to the high concentration of diethyl ether. Multiple anaesthesia sessions using either diethyl ether or halothane/O2/N2O did not clearly influence adrenaline and noradrenaline levels. Diethyl ether induced a sharp rise in plasma ACTH and glucose levels, irrespective of the concentration used. The response of the ACTH and glucose was similar for single and multiple exposure. An increased response of ACTH, corticosterone and glucose to sham anaesthesia following multiple induction of anaesthesia was observed for the high concentration of diethyl ether only. Halothane/O2/N2O raised plasma glucose without differences between single and multiple anaesthesia sessions. Upon sham anaesthesia following multiple exposures to halothane/O2/N2O, glucose levels were significantly increased. This study indicates that repeated anaesthesia in rats can elicit an increased stress response during subsequent handling and change of environment.

Adrenocorticotropic Hormone↗
PubMed2001

Disordered visual processing and oscillatory brain activity in autism and Williams syndrome.

Two developmental disorders, autism and Williams syndrome, are both commonly described as having difficulties in integrating perceptual features, i.e. binding spatially separate elements into a whole. It is already known that healthy adults and infants display electroencephalographic (EEG) gamma-band bursts (around 40 Hz) when the brain is required to achieve such binding. Here we explore gamma-band EEG in autism and Williams Syndrome and demonstrate differential abnormalities in the two phenotypes. We show that despite putative processing similarities at the cognitive level, binding in Williams syndrome and autism can be dissociated at the neurophysiological level by different abnormalities in underlying brain oscillatory activity. Our study is the first to identify that binding-related gamma EEG can be disordered in humans.

Adult↗
PubMed2001

Antidepressant prescription for depression in general practice in The Netherlands.

OBJECTIVE: To evaluate diagnoses and the prescription of antidepressants drugs for depression, based on data from 1993 to 1998 related to consultations for depression in general practice in the Netherlands. METHOD: An exploratory analysis of data provided by IMS Health. Consecutive annual representative samples of 640 GPs regularly registered data on morbidity and (drug) treatment for specific medical problems in special booklets for a period of one week. The data refer to consultations for depression. The diagnoses were initially based on ICD-9 criteria and later ICD-10 criteria for depression. MAIN OUTCOME MEASURES: Number of diagnoses of depression and number of prescriptions for antidepressants. RESULTS: The number of first consultations for depression rose gradually, from 909 in 1993 (95% CI: 774 to 1043), to 1,482 (CI: 1292 to 1672) in 1998: an increase of 63%. For an individual GP, this represents an increase from 18 to 30 in first consultations for depression. The number of prescriptions for antidepressants also increased, mainly during repeat consultations: a 278% increase, from 3,708 in 1993 to 14,024 in 1998 (CIs: 3,504 to 3,912 and 13,252 to 14,796). Antidepressants were prescribed during the first consultation 564 times in 1993 compared with 1,080 times in 1998. The first contact with a GP for depression led to an antidepressant prescription in 62% of cases in 1993 and 73% in 1998. Although the guidelines issued by the Dutch College of General Practitioners in 1994 recommended tricyclic antidepressants (TCAs) for the treatment of depression, paroxetin, fluoxetin, and mirtazapin (SSRIs) accounted for 56% of the prescribed antidepressants. CONCLUSION: Between 1993 and 1998, GPs in the Netherlands prescribed increasingly more antidepressants, and they prescribed more SSRIs than TCAs. Furthermore, GPs diagnose depression more frequently and the number of repeat consultations has increased.

Antidepressive Agents↗
PubMed2001

Serum thrombopoietin levels in relation to disease status in patients with immune thrombocytopenic purpura.

Pre- and post-treatment serum thrombopoietin (TPO) concentration was measured in 35 patients with immune thrombocytopenic purpura (ITP). Mean post-treatment levels were significantly lower (P = 0.02) than pretreatment and not different for treatment modality. No significant correlation between pre- or post-treatment TPO and platelet counts was demonstrable (R = -0.325, P = 0.056 and R = -0.227, P = 0.190 respectively). In patients with very low platelet counts (< or =20 x 10(9)/l), pretreatment serum TPO was significantly higher than in patients with higher counts (P = 0.033). The logarithm of the platelet turnover rate, measured in 15 patients, correlated with pretreatment TPO levels (R = 0.64). These findings suggest a contributory role for TPO in the mechanism of ITP.

Blood Platelets↗
PubMed2001

Categorical perception of facial expressions by 7-month-old infants.

Recent research indicates that adults show categorical perception of facial expressions of emotion. It is not known whether this is a basic characteristic of perception that is present from the earliest weeks of life, or whether it is one that emerges more gradually with experience in perceiving and interpreting expressions. We report two experiments designed to investigate whether young infants, like adults, show categorical perception of facial expressions. 7-month-old infants were shown photographic quality continua of interpolated (morphed) facial expressions derived from two prototypes of fear and happiness. In the first experiment, we used a visual-preference technique to identify the infants' category boundary between happiness and fear. In the second experiment, we used a combined familiarisation-visual-preference technique to compare infants' discrimination of pairs of expressions that were equally physically different but that did or did not cross the emotion-category boundary. The results suggest that 7-month-old infants (i) show evidence of categorical perception of facial expressions of emotion, and (ii) show persistent interest in looking at fearful expressions.

Child, Preschool↗
PubMed2001

Mean clinical challenge rate and level of recognition of depression remain unchanged after two years of vocational training.

OBJECTIVES: Our aim was to evaluate whether trainees encounter more difficult clinical situations (clinical challenge rate) and more patients with signs of depression in the last year of their training (T(1)) than in the first year (T(0)), and whether depression is recognized by trainees more frequently at T(1) than at T(0). METHODS: An evaluation was undertaken of videotapes made by a random sample of 48 vocational trainees in general practice. Experienced staff members (GPs) assessed the clinical challenge rate of consultations at the two time points with the reliable and valid Amsterdam Clinical Challenge Scale (ACCS). They also rated the presence of signs of depression in the consultations (yes/no) and whether these were recognized by the trainee (yes/no). RESULTS: Baseline and follow-up measurements (T(0) and (T(1))) were available for 45 trainees, from the original cohort of 48 at T(0), and for 527 consultations. Both at T(0) and at T(1), the mean ACCS score was 2.3 (T(0) SD = 0.95; n = 269) (T(1) SD = 0.92; n = 258). For each trainee, the mean difference in ACCS score between T(0) and T(1) was 0.01 [95% confidence interval (CI) -0.15 to 0.17]. According to staff-assessments, 66 patients had signs of depression (34 at T(0) and 32 at T(1)). Trainees recognized depression in 12 consultations (12/34 = 35%) at T(0) and in 11 consultations (11/32 = 34%) at T(1) (relative risk 1.0; 95% CI 0.4-2.9). CONCLUSION: A focus on the challenge level of consultations, an individualized, integrated approach and the introduction of a new final consultation skills examination may be the way forward.

Clinical Competence↗
PubMed2001

Recording and analyzing high-density event-related potentials with infants. Using the Geodesic sensor net.

This article provides an overview of the use of the Geodesic sensor net system for high-density event-related potential (ERP) recording in infants. Some advantages and disadvantages of the system, as applied to infants, are discussed. First, we illustrate that high-density data can be recorded from infants at comparable quality to that observed with conventional (low density) ERP methods. Second, we discuss ways to utilize the greater spatial information available by applying source separation and localization procedures. In particular, we focus on the application of one recent source separation method, Independent Component Analysis (ICA). Finally, we show that source localization can be applied to infant high-density data, although this entails adopting a number of assumptions that remain to be verified. In the future, with improved source separation algorithms, we suggest that single-trial or single-subject analyses may become feasible.

Adult↗
PubMed2001

Determinants of different dimensions of disease severity in asthma and COPD : pulmonary function and health-related quality of life.

OBJECTIVE: To identify determinants of pulmonary function and health-related quality of life (HRQOL) to better understand disease severity in patients with asthma and COPD. DESIGN: Observational study. SETTING: Dutch general practice. PATIENTS: We studied 837 asthma patients and 231 COPD patients. RESULTS: The association between pulmonary function and HRQOL was poor for asthma (beta = 0.10) and COPD (beta = 0.19). Multivariately, in asthma, lower pulmonary function was associated with male gender, region of living, current smoking, use of inhaled short-acting bronchodilators, longer duration of disease, and higher diurnal variation in peak expiratory flow. In COPD, lower pulmonary function was associated with male gender, use of inhaled bronchodilators, more days and nights disturbed by respiratory complaints, not wheezing, and bronchial hyperresponsiveness. Reduced HRQOL was associated most strongly with more days and nights disturbed by respiratory complaints and dyspnea in both asthma and COPD. In asthma, additional associations were found with younger age, lower educational level, region of living, comorbidity, use of inhaled bronchodilators and corticosteroids, wheezing, chronic cough, sputum production, and bronchial hyperresponsiveness. In COPD, lower age, not smoking, chronic cough, and sputum production were associated with reduced HRQOL. CONCLUSIONS: Pulmonary function and HRQOL appear to highlight different aspects of disease severity in asthma and COPD. Therefore, both measures should be taken into account in order to get a complete picture of severity of disease.

Adolescent↗