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PubMed2004

Defining generic objectives for community-based education in undergraduate medical programmes.

RATIONALE: The availability of a framework for the definition of generic objectives for community-based education (CBE) programmes may assist in the rational design of objectives for specific CBE programmes. STRATEGY: Factors impacting on community health from the perspective of a developing country were collected. Potential assistance from medical students to communities to improve their health status was determined. Competencies required in students to execute tasks in the community were defined and eventually educational objectives to develop these competencies in the students were established. METHODS: Factors impacting on community health and activities of medical students in CBE programmes were identified by review of literature and Internet resources. Competencies desired for execution of tasks by students and educational objectives to develop these competencies were defined by us and checked against pertinent literature. A draft table representing the 4 elements of the framework was discussed by an international group of experts for external validation. MAIN OUTCOMES: A total of 26 factors impacting on community health were identified and clustered in 5 domains. Twenty-one generic objectives for CBE programmes were defined to develop the required competencies in students. Analogues of each of these 21 objectives were found in at least 1 publication specifying objectives for specific CBE programmes but none of these publications stated any objective not covered by our list of generic objectives. CONCLUSION: It proved possible to develop a framework to define generic objectives for CBE programmes. An example was elaborated from the perspective of a medical school in a developing country.

Clinical Competence↗
PubMed2003

Allowing for genotyping error in analysis of unmatched case-control studies.

A commonly-used method for testing for association between disease and a single-nucleotide polymorphism (SNP) is to compare the frequencies of the SNP genotypes in a sample of unrelated cases to those in a sample of unrelated controls drawn from the same population (an unmatched case-control study). A drawback of such a study is that it is impossible to detect genotyping errors, and few methods have been developed to allow for the presence of undetected genotyping errors. In this paper, we obtain analytic formulae for estimates of genotypic relative risks in terms of error probability (e). In general, e will be unknown. We investigate the effect of assuming both correct and incorrect values of e on power and type I error, and also on the genotypic relative risk estimates. The choice of e was found to have no effect on power or Type I error probability (provided a 2df test was used, allowing relative risks of homozygotes and heterozygotes to differ). However, overestimating e in the presence of a true association was found in general to bias relative risk estimates away from the null, with underestimates of e having the opposite effect. Although e is unknown, it may be estimated from an external "validation" study, such as genotyping a sample of unrelated individuals twice and counting the discrepancies. Simulation results suggest that, for such a study, 25 individuals would be sufficient to give approximately unbiased estimates of relative risks.

Case-Control Studies↗
PubMed1998

Predicting pass rates on the American Board of Internal Medicine certifying examination.

Our objective was to determine the ability of the internal medicine In-Training Examination (ITE) to predict pass or fail outcomes on the American Board of Internal Medicine (ABIM) certifying examination and to develop an externally validated predictive model and a simple equation that can be used by residency directors to provide probability feedback for their residency programs. We collected a study sample of 155 internal medicine residents from the three Virginia internal medicine programs and a validation sample of 64 internal medicine residents from a residency program outside Virginia. Scores from both samples were collected across three class cohorts. The Kolmogorov-Smirnov z test indicated no statistically significant difference between the distribution of scores for the two samples (z = 1.284, p = .074). Results of the logistic model yielded a statistically significant prediction of ABIM pass or fail performance from ITE scores (Wald = 35.49, SE = 0.036, df = 1, p < .005) and overall correct classifications for the study sample and validation sample at 79% and 75%, respectively. The ITE is a useful tool in assessing the likelihood of a resident's passing or failing the ABIM certifying examination but is less predictive for residents who received ITE scores between 49 and 66.

Internal Medicine↗
PubMed2001

Impact of pediatric epilepsy on the family: a new scale for clinical and research use.

PURPOSE: There is no brief, global instrument available that specifically measures the psychosocial impact of pediatric epilepsy on the family. An 11-item scale was created for parents' use to evaluate the influence of epilepsy on the major aspects of their family and child's life. This will be a helpful tool both in the clinical setting and as an outcome measure for research studies. METHODS: Mothers rated their child's quality of life on a visual analogue scale (1-6) and completed the Impact of Pediatric Epilepsy Scale (IPES), which assesses the impact on academic achievement, participation in activities, health, relationships with family and with peers and siblings, social activities, self-esteem, and the caregiver's hopes for their child's future adapted from the scale developed by Jacoby. External validation was determined by comparison of the IPES with physicians' reports of the characteristics of the child's epilepsy and neurological limitations and parents' ratings on the Family Environment Scale or Parenting Stress Index. In addition, each school-aged child completed the Piers-Harris Children's Self-Concept Scale, Brother-Sister Questionnaire, and Loneliness Scale. Teachers of children completed the Academic Performance Rating Scale. Seven days later, retest reliability of the IPES was evaluated. RESULTS: Ninety-seven mothers of children aged 2-16 years completed the IPES and the appropriate family and age-related questionnaires. Internal validation on the IPES yielded a Cronbach's a for the scale of 0.92. A significant Pearson's correlation indicated that total scores were consistent over time (r = 0.81). Spearman's correlations for the individual items were also significant, ranging from 0.48 to 0.78. Significant Spearman's correlations also indicated that quality of life was negatively related to impact on each of the 11 items of psychosocial function. Children with IPES scores above the median differed in some psychosocial aspects from those who scored below. Their parents were more stressed, their siblings were more respectful, they had lower self-esteem, and they experienced more emotional problems. Total impact was also significantly related to seizure frequency, total number of medications taken, number of visits to a physician in the previous year, and number of nights spent in hospital for neurological reasons. CONCLUSIONS: The IPES is an accurate, acceptable, and quick measurement tool that reflects the way in which childhood epilepsy has an impact on the child and on family life. It may be helpful in routine clinical care and may be useful in the research setting to find ways to improve the lives of children with epilepsy.

Adolescent↗
PubMedDate not supplied

Incidence of intramammary infections during the dry period without or with antibiotic treatment in dairy cows--a quantitative analysis of published data.

The study was aimed at summarising the literature that compares the incidence levels of spontaneously occurring intramammary infections (IMI) during the dry period, without versus with antibiotic dry cow treatment (DCT). A meta-analytic relative risk (RR) calculation was implemented when a priori relevant. Two main categories of comparison were used in the 36 selected papers. In the first category, the udder quarters were randomly allocated (at quarter or cow level) to an untreated or a treated group. Quarter incidence averaged 12.8% (weighted mean) in untreated quarters, and depending on the DCT used, from 6.6 to 8.0% in treated quarters. The meta-analytic RR of new IMI for untreated versus treated quarters varied from 1.54 to 1.94, depending on the DCT used. DCT was mainly found effective against IMI due to streptococci and coagulase-positive staphylococci. Based on only a few papers, the application of an internal teat sealer was associated to a quite similar (or possibly better) protection against IMI than DCT, but only in a subpopulation of particular (selected) cows. In the second category of studies, a selective dry cow or quarter antibiotic-treatment (selective DCT or DQT), according to cow or quarter selection criteria, was compared to blanket DCT. The meta-analytic RR of new IMI was 1.71 for selective DCT versus blanket DCT. Selective DQT seemed to be more at risk than selective DCT, but consisted of treating a much lower proportion of quarters. The summary-results provided by our meta-analysis should only be used with caution, due to possibly low external validity. More research seems to be relevant on the risk factors of new IMI during the dry period to make the outcomes of omission of DCT in selected cows more predictable under field conditions.

Animals↗
PubMed2000

Hospital factors associated with emergency center patients leaving without being seen.

We developed a statistical model that would identify and quantify the relative contributions of different factors hypothesized to impact the frequency of emergency center (EC) patients who leave without being seen (LWBS). We performed an analysis of the daily counts of patients that registered in our EC during a 21-month period who then LWBS. Candidate predictor variables included the number of patients seen, and the number admitted to the hospital, for each area of our EC, as well as the hours of faculty double coverage, and the day of the week. Univariate analyses were performed using standard methods. Multivariate analysis was performed using the general linear model. A backward selection procedure was used to eliminate statistically insignificant variables until all remaining independent variables had P-values < or = .05. External validation and analysis of the stability of the estimated regression coefficients of the model were evaluated using bootstrap methods. Two-tailed tests and a type I error of 0.05 were used. During the period studied, 133,666 patients were registered in the EC and 9,894 (7.4%) left. Multivariate analysis identified six variables that were significantly associated with LWBS. The fitted model containing all six variables explained 52.8% of the variability observed in LWBS frequency. The most powerful predictor of LWBS was total number of patients cared for in the main ED. This accounted for 46.4% of the observed variation in LWBS. The total number of trauma and resuscitation patients, and the total number of observation unit admissions to the hospital were also associated with increased LWBS. More pediatric cases seen in the main ED, weekends, and additional faculty coverage were associated with fewer patients leaving. Efforts to decrease the LWBS rate will be most successful if they address the issue of main ED volume.

Adolescent↗
PubMed2002

Do ED patients with migraine headaches meet internationally accepted criteria?

A recent editorial criticized emergency medicine researchers who study the treatment of acute migraine for failing to standardize patients according to definitions provided by the International Headache Society (IHS). In fact, most emergency medicine-based studies of migraine therapies have not used IHS Criteria (IHSC) for patient inclusion and are not uniform in the definition of acute migraine. The purpose of this study was to determine the percentage of patients with complaint of headache who present to the emergency department with a prior diagnosis of migraine and/or emergency department discharge diagnosis of acute migraine that meet IHSC. The study was a prospective observational study performed in a community-based and consisted of consecutive patients with a chief complaint of headache who presented to any 1 of 6 study investigators. Patients recorded historical data on a standard form; Clinical data were recorded by the investigators. Ninety-five percent confidence intervals and the Fisher exact test were calculated as appropriate. One hundred eighty-five patients were enrolled (study group): 70% were women, 43% had prior imaging studies to diagnose the etiology of the headache, and 26% had a diagnostic workup during the current emergency department visit; the probable headache etiology was found in 12 of these cases. Only 3 patients that had an ED workup that fit IHSC. Forty-nine percent of all patients had a prior diagnosis of migraines; 41 of these patients (45%) met IHSC. Forty-two percent of all patients had an emergency discharge diagnosis of acute migraine; of these, 43 (56%) met IHSC. Forty-four out of 96 (46%; 95% confidence interval = 35%-57%) patients with a prior diagnosis of migraine and/or discharge diagnosis of acute migraine met IHSC. Modification of the IHSC, by removing restrictions for headache duration and number of prior episodes, would have markedly increased the percentage of patients with a previous migraine and/or emergency discharge diagnosis of acute migraine that met other qualitative IHSC (94%). Of the patients with prior migraine diagnosis and/or emergency department diagnosis of acute migraine, men and women were equally as likely to meet IHSC (41% v 48%, P = 0.79). Less than half of patients with a prior diagnosis and/or final emergency discharge diagnosis of acute migraine met IHSC. Our findings raise concerns about the external validity of prior emergency department-based research of acute migraine therapy and the utility of the IHSC for future research. Modification of the IHSC for emergency medicine research should be considered.

Acute Disease↗
PubMed2003

Heterogeneity of symptom pattern, psychosocial factors, and pathophysiological mechanisms in severe functional dyspepsia.

BACKGROUND & AIMS: Categorization of functional dyspepsia into subgroups is based on expert opinion according to (dominant) symptoms or on underlying pathophysiological mechanisms. We used an evidence-based approach to the determination of subtypes of functional dyspepsia. METHODS: Consecutive functional dyspepsia patients were recruited from a tertiary referral center. The following were performed: (1) exploratory (EFA) and confirmatory factor analysis (CFA) of symptom patterns in a large group of patients with functional dyspepsia; (2) external validation of these factors by the determination of their association pattern with physio- and psychopathological mechanisms, and with health-related quality of life and sickness behavior; and (3) cluster analysis of their distribution in this population. RESULTS: Both EFA and CFA do not support the existence of functional dyspepsia as a homogeneous (unidimensional) condition. A 4-factor model is found to be valid, with differential distribution within the patient population according to cluster analysis. Factor 1 is characterized by nausea, vomiting, early satiety, and weight loss and factor 2 by postprandial fullness and bloating. Both factor 1 and 2 are associated with delayed emptying, but only factor 1 is associated with younger age, female sex, and sickness behavior. Factor 3 is characterized by pain symptoms and associated with gastric hypersensitivity and several psychosocial dimensions including medically unexplained symptoms and health-related quality of life dimensions. Factor 4, characterized by belching, is also associated with hypersensitivity, but is unrelated to psychosocial dimensions. CONCLUSIONS: In a tertiary care population, functional dyspepsia is a heterogeneous condition characterized by 4 major dimensions differentially associated with psychopathological and physiopathological mechanisms.

Abdominal Pain↗
PubMed2003

Cost-effectiveness analysis of inhaled corticosteroids in asthma: a review of the analytical standards.

PURPOSE: To determine whether published cost-effectiveness studies on inhaled corticosteroids (ICS) in asthma adhered to basic analytical standards as defined in health economic textbooks and in guidelines assessing and comparing efficacy and safety. METHODS: Original cost-effectiveness studies published between 1990 and 2000 in general medical or economic journals were reviewed to assess the adherence to five fundamental methodological principles: (1) design of the study, (2) choice of perspective and corresponding costs, (3) choice of outcome measure, (4) marginal cost analysis, and (5) sensitivity analysis and discussion about external validity. For each principle, the studies were ranked as high, medium or low quality. RESULTS: Most of the 18 studies included were ranked medium on the first two principles. The studies adhered to a higher degree to the remaining three principles. Only three studies were high ranked in all five principles. The number of principles fulfilled increased over time. Studies comparing pharmaceutical products from competing companies were typically short-term studies, designed for other purposes than health economic analyses, and, in general, did not use therapeutically equivalent dosing. CONCLUSIONS: Attention should be drawn to the study design, the weak correspondence between perspective and costs, and especially to the impact of bias in health economic results when comparing different doses of ICSs.

Administration, Inhalation↗
PubMedDate not supplied

[The Inflammatory Bowel Disease Stress Inventory (IBD-SI). A measure of psychosocial stress in patients with IBD].

The "Inflammatory Bowel Disease Stress Inventory (IBD-SI)" measures a broad spectrum of disease-specific every day stress factors in patients with inflammatory bowel disease (IBD). Based on a multistage factor analysis on 300 CED patients, the final form comprises 32 items assigned to 8 different domains: depressed mood, doctor-patient relationship, anxiety about loss of bowel control, occupational impairment, worries about deteriovation, stress from medical treatment, impairment of sexuality/partnership and physical complaints. In addition, a global stress score can be obtained. The reliability values of the 8 subscales with 4 items each indicate a good internal consistency (alpha = 0.76 - 0.89) and a high retest reliability (r = 0.75 - 0.92). Significant correlations with medical and psychological variables supports the external validity of this questionnaire.

Adult↗
PubMed2002

Treatment of depressive disorders with and without medication - a naturalistic study.

OBJECTIVE: Although randomized clinical trials are the standard method for comparing the efficacy of various depression treatments, the external validity and generalizability of findings obtained by this approach can be questioned for several reasons. In this naturalistic study, we compared the effectiveness of treatments conducted by psychiatrists and clinical psychologists without prescription of drugs to treatments by psychiatrists and physicians using antidepressant agents in patients with depressive disorders in a representative sample of the normal population. Our assumption was that this sample is more representative for subjects treated for depressive disorders than subjects included in controlled trials. METHODS: In a post hoc analysis, the health status of depressed patients under treatment for major, minor or recurrent brief depression with medication (20 patients) and without medication (30 patients), and untreated depressed subjects were compared over a one-year period using SCL-90-R depression scale scores. RESULTS: At baseline, the two treatment groups were comparable in terms of diagnosis and severity of symptoms. Treatment effects were relatively small; patients treated with antidepressants tended to improve, whereas patients treated without drugs deteriorated slightly over one year. Seven years later, treated and untreated subjects no longer differed. CONCLUSION: The results are consistent with previous studies on usual care of depressed patients showing low response rates for non-standardized treatments outside of research settings. Despite a number of methodological shortcomings (small sample size, heterogeneity of subjects and treatments, unusual rating instruments), the results presented here are unique, and provide relevant insight into usual care of depressed patients. This study underlines the importance of standardized psychotherapy and pharmacotherapy in routine practice, of studies investigating the transferability of results of outcome studies across clinical populations, and of quality assurance in primary care psychiatry.

Adult↗
PubMed2004

[The problem of response in epidemiological studies in Germany (part I)].

To achieve high response rates in German epidemiological studies is growing more difficult. Low response in epidemiological studies may decrease the acceptance of the results. Response, however, is not identical with the quality of a study. In the first part of this paper various definitions of response (contact, cooperation, response, recruitment proportions) are introduced and discussed in the context of different study designs with reference to practical examples. A population-based survey such as the Study of Health in Pomerania (SHIP) investigates the distribution of risk factors and health-related endpoints. Surveys should yield representative results which can be generalised to apply to the entire population (external validity). This study design usually requires large participitation proportions. In a prospective cohort study such as the European Investigation into Cancer and Nutrition (EPIC) the emphasis is on internal validity. A stable study population willing to participate in regular follow-ups is a primary recruitment goal. If the response in a case-control study such as the Northern Germany Leukaemia and Lymphoma Study (NLL) is low, the priority is to achieve approximately equal response proportions for cases and controls. Simultaneous public relation and media activities can improve participitation in a study. Multidimensional strategies combining public communications, cooperation with local and regional officials and frequent press and media coverage are emphasised. The second part of this paper will discuss methods to quantify the effects of the response proportions on the validity of the study results.

Adult↗
PubMed2004

Effects of music on work-rate distribution during a cycling time trial.

Previous research work on the ergogenic effects of music has mainly involved constant power tests to exhaustion as dependent variables. Time trials are more externally valid than constant power tests, may be more reliable and allow the distribution of self-selected work-rate to be explored. We examined whether music improved starting, finishing and/or overall power during a 10-km cycling time trial, and whether heart rate and subjective responses to this time trial were altered by music. Sixteen participants performed two 10-km time trials on a Cybex cycle ergometer with, and without, the presence of a form of dance music known as "trance" (tempo = 142 beats x min (-1), volume at ear = 87 dB). Participants also completed the Brunel music rating inventory (BMRI) after each time trial in the music condition. The mean +/- SD time to complete the time trial was 1030 +/- 79 s in the music condition compared to 1052 +/- 77 s without music (95 % CI of difference = 10 to 34 s, p = 0.001). Nevertheless, ratings of perceived exertion were consistently (0.8 units) higher throughout the time trial with music (p < 0.0005). The interaction between distance and condition was significant for cycling speed measured during the time trial (p = 0.007). The largest music-induced increases in cycling speed and heart rate were observed in the first 3 km of the time trial. After completion of the BMRI, participants rated the "tempo" and "rhythm" of the music as more motivating than the "harmony" and "melody" aspects. These results suggest that music improves cycling speed mostly in the first few minutes of a 10-km time trial. In contrast to the findings of previous research, which suggested that music lowers perceived exertion at a constant work-rate, the participants in our time trials selected higher work-rates with music, whilst at the same time perceived these work-rates as being harder than without music.

Adult↗
PubMed2006

Acceptability of power variation during a simulated hilly time trial.

We investigated the acceptability of power variation during a cycling time trial (TT) with simulated uphill and downhill sections. Seven cyclists first completed an 800-kJ self-paced TT on a simulated flat course. An 800-kJ TT course with four sections of uphill/downhill was then modeled. Each section involved 100 kJ of cycling up a simulated gradient of 5 % followed by 100 kJ of riding down a simulated gradient of - 5 %. Participants were required to complete this simulated course using two pacing strategies; (i) at a constant power equivalent to the mean power achieved during the initial TT, and (ii) increasing power by 5 % of mean power when traveling uphill (mean duration of each climb = 714 s) and decreasing power in the downhill sections (mean duration of each descent = 190 s), so that overall mean power was equivalent to that in (i). All participants maintained this variable power strategy during the first half of the TT, but two riders could not adhere to the power variations during the final 400 kJ. Nevertheless, mean +/- SD finish time for the variable power trial (3670 +/- 589 s) was significantly faster than that for the constant power TT (3758 +/- 645 s), the 95 % confidence interval for the percentage improvement being 0.4 to 4.3 %. Heart rate and lactate responses were highest in the initial self-paced TT and did not differ between the subsequent constant and variable power trials. Ratings of perceived exertion were also similar between trials. In our externally-valid TT, we found that some cyclists cannot fully adhere to a pacing strategy involving an approximate +/- 5 % variation in mean power in parallel with gradient variation. Nevertheless, an important time saving can still result even if a variable pacing strategy is only partially adopted during a hilly time trial, so that no additional physiological strain is incurred.

Adult↗
PubMed1983

The impact of therapeutic advances in widening the nosologic boundaries of affective disorders: clinical and research implications.

The clinical boundaries of affective disorders have been considerably broadened in the past few years, in part due to therapeutic advances. Many psychotic patients who were formerly considered schizophrenic are now being treated with thymoleptic agents. Clinicians as well as researchers are seeing many patient with mood disturbance in ambulatory settings where anxious, intermittent, masked, and characterological presentations are common. Mood disorders are also being increasingly diagnosed in children, the elderly and in patients in primary care settings. Do these changes in diagnostic practice reflect therapeutic fashion? Are there external validating criteria by which the affective origin of these diverse conditions can be ascertained? In discussing the clinical and research dimensions of these questions, we provide a framework for resolving the methodologic issues involved.

Aging↗
PubMed1998

The standardized psychometric assessment of altered states of consciousness (ASCs) in humans.

The APZ questionnaire was developed in order to explore hypotheses on ASCs. First -- in a series of 11 experiments using different induction methods on N = 393 healthy subjects -- the hypothesis was tested that ASCs have major dimensions in common irrespective of the mode of their induction. In the International Study on Altered States of Consciousness (ISASC) the external validity of the experimental results was assessed. The ISASC was carried out on a total of N = 1133 subjects in six countries. The main results of the experimental studies were corroborated in the field studies. The results can be summarized as follows: the common denominator of ASCs is described by three oblique dimensions, designated as "Oceanic Boundlessness (OSE)", "Dread of Ego Dissolution (AIA)" and "Visionary Restructuralization (VUS)". The reliability and validity of the scales are satisfactory. Tested versions of the APZ scales are available in English (UK, USA), German, Italian and Portuguese. Psychometrically as yet untested versions exist in Dutch, Finnish, French, Greek, Spanish and Russian. The APZ questionnaire has become the international standard for the assessment of ASCs, thus helping to integrate research. A psychometrically improved version exists in German (OAV questionnaire). The BETA questionnaire, which measures the dimensions "Vigilance Reduction (VIR)" and "Auditive Alteration (AVE)" is also available in German. These dimensions are most likely etiology-dependent.

Clinical Trials as Topic↗
PubMed1998

Use of the census samples of anonymised records (SARs) and survey data in combination to obtain estimates at local authority level.

"The Samples of Anonymised Records (SARs) provide large representative samples of 278 small areas of Britain and are thus of great value to planners. This paper describes an approach which takes advantage of the fact that the SARs comprise individual records. Estimates of the proportions of local authority populations suffering serious illness were produced by use of data from the 4th National General Practitioner Morbidity survey and the 2% anonymised sample of individual 1991 Census records. These estimates were compared with external validation criterion, all-cause mortality. The correlation was high, providing some evidence of the validity of the approach."

Cause of Death↗
PubMed2000

How reliable are human phylogenetic hypotheses?

Cladistic analysis of cranial and dental evidence has been widely used to generate phylogenetic hypotheses about humans and their fossil relatives. However, the reliability of these hypotheses has never been subjected to external validation. To rectify this, we applied identical methods to equivalent evidence from two groups of extant higher primates for whom reliable molecular phylogenies are available, the hominoids and papionins. We found that the phylogenetic hypotheses based on the craniodental data were incompatible with the molecular phylogenies for the groups. Given the robustness of the molecular phylogenies, these results indicate that little confidence can be placed in phylogenies generated solely from higher primate craniodental evidence. The corollary of this is that existing phylogenetic hypotheses about human evolution are unlikely to be reliable. Accordingly, new approaches are required to address the problem of hominin phylogeny.

Animals↗