[Helicobacter pylori--do we know what we are doing?].
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Dyspepsia↗
Biomedical subjects
T Johannessen
Publications and source records attributed to T Johannessen.
[Teaching clinical decision making in Trondheim].
In the new medical curriculum at the University of Trondheim the preliminary teaching in clinical epidemiology is organized as a series of courses held in the third and fourth year. The objective is to develop skills in clinical appraisal based on scientific knowledge. A workbook and answers to exercises are provided for each course. The workbooks contain short introductions to important clinical epidemiological principles, as well as clinical problems which the students try to solve. The students' activities vary from reading to working with exercises and discussing the various topics. The courses give the students the opportunity to practice their newly acquired knowledge and to apply it to their clinical thinking.
Curriculum↗
[Standardized patients in general practice--a new method for quality assurance in Noway].
Standardized patients were sent to general practitioners who use the patient list system in Trondheim in order to register daily clinical practice without the patient being unmasked. The authors explain what a standardized patient is, how they are taught to present a disease, and how they report on the consultation in a valid and reliable way. They also describe how the standardized patients were introduced into the doctors' patient list system. The doctors were informed about the project in advance. Twenty-three doctors were visited twice and one doctor was visited once by a standardized patient. At two of the visits the patient was unmasked. The conclusion is that the use of standardized patients is a valid, reliable and practical method for quality assurance in general practice in Norway.
Family Practice↗
The natural course of peptic ulcer disease and its predictors.
BACKGROUND: Little is known about today's natural course of peptic ulcer disease (PUD). METHODS: A follow-up study based on a structured telephone interview was attempted in 728 patients with an endoscopic diagnosis of peptic ulcer in 1980-84. RESULTS: Seven patients (1%) died because of PUD during the 8- to 10-year follow-up period. Of the 441 interviewed patients 15.2% had experienced no further clinical manifestations of PUD, 10.9% had had bleeding and 0.7% perforation, and 17.5% had been operated on. The operated patients reported fewer symptoms (p < 0.01) during the last 2 weeks before the interview than those not operated on. On an average the unoperated patients had had symptoms and had used histamine-2-receptor antagonists (H2RA) 12 and 10 weeks per year, respectively. Long-term treatment with H2RA was reported by 18%. More than one-third (36%) of the unoperated patients stated that the symptoms had had a significant negative impact on their lives. Age at onset of disease and index ulcer, family history, use of anti-inflammatory drugs and alcohol, bleeding, and another chronic disease were found to be significant predictors of the course. CONCLUSION: In more than one-third of the patients with PUD the course is still burdened with many symptoms and complications.
Adolescent↗
Management of peptic ulcer disease in general practice.
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Drug Therapy, Combination↗
[The physician-patient course in the medical education in Trondheim].
The new medical curriculum at the University of Trondheim is based on problem-based learning in small groups and integrated teaching. An important element is the doctor-patient training programme run weekly during the two first years. This implies that, every other week, the students spend three hours in general practice. During the intervening week they spend three hours in a skills laboratory. The programme aims to train the students' communication skills in the doctor-patient relationship, to integrate basic sciences with clinical thinking and examinations, and to teach the students clinical skills. The programme enables the students to have early contact with patients, and provides them with personal supervision and support. 17 general practitioners serve as teachers in clinical practice, while specialists from most departments at the Faculty are involved as teachers at the skills laboratory.
Curriculum↗
The intensity and variability of symptoms in dyspepsia.
During the waiting time for upper gastrointestinal endoscopy 165 patients with dyspepsia completed a questionnaire and a diary for daily measurements of the symptoms pain, heartburn, and global complaints. 23 patients (14%) had peptic ulcer disease (PUD), 18 oesophagitis (11%), and the rest were labelled nonulcer dyspepsia (NUD). NUD was further subdivided into ulcer-like, reflux-like, dysmotility, and essential NUD by means of predefined symptom profiles. 39 (24%) patients were on H2 receptor antagonist treatment. In general, the intensity of the daily symptoms was rather low, and except for a higher rating of heartburn in oesophagitis, there were no significant differences between PUD, oesophagitis, and NUD--treated or untreated. NUD patients with reflux-like dyspepsia had significantly more heartburn than the group with essential NUD; otherwise there were no differences between the subgroups of NUD. The individual daily ratings for abdominal pain, heartburn, and global symptoms varied by an average standard deviation of 64%, 97% and 47% of the mean values, respectively, and were independent of treatment or diagnoses. There was an approximately 40% probability that two successive days had different levels of symptoms. Only 10% of the patients showed stable symptoms, and the patients were completely symptom-free for 20% of the observation period. Symptoms in dyspepsia patients disclosed low intensity and high variability in this study. Such factors may be important sources of bias in clinical trials.
Adolescent↗
[Why change medical education--do we have anything to learn from the universities of New Mexico, McMaster and Harvard?].
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Canada↗
Cimetidine on-demand in dyspepsia. Experience with randomized controlled single-subject trials.
Double-blind randomized controlled trials in single subjects (N of 1 RCTs) have demonstrated a beneficial symptomatic effect of cimetidine in reflux- or ulcer-like non-ulcer dyspepsia (NUD). However, spontaneous fluctuations in symptoms reduce the validity of such trials when performed as continuous trials with fixed dosages. This study was carried out to identify individual responders to cimetidine in NUD, peptic ulcer disease, and oesophagitis and to confirm the beneficial average effect of cimetidine in these clinical entities. We evaluated N of 1 multi-crossover trial designs, which compare the effects of single doses of cimetidine and placebo taken on-demand for symptomatic relief. Each trial consisted of six cimetidine (400 mg or 800 mg) and six placebo tablets randomized in successive pairs. The symptomatic effect of each tablet was measured 1/2-6 h after the intake. Outcomes were assessed by individual p values and confidence intervals. A minimal clinically important difference was defined, to assess the clinical significance as demonstrated by the confidence intervals. Thirteen of 25 patients (52%) with reflux- and ulcer-like NUD obtained individual p values below 0.20. Similarly, 7 of 9 patients (78%) with oesophagitis and 6 of 12 patients (50%) with peptic ulcer obtained such p values. On the basis of the 80% confidence intervals the corresponding numbers of subjects with clinically significant effect were six (NUD), three, and three. The combined data showed a significantly better effect of cimetidine than of placebo (p less than 0.0001) in each of the three diagnostic groups studied. Cimetidine taken on-demand may have a rapid symptom-relieving effect in dyspepsia.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Controlled trials in single subjects. 1. Value in clinical medicine.
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Cimetidine↗
Statistical power in single subject trials.
A controlled single subject trial compares the efficacy of a new treatment with a control treatment in an individual patient. The treatments are administered in a double-blind, randomized, multi-crossover sequence of periods. During the trial response measures are obtained from each treatment period and form the basis for the statistical evaluation. Similar to the situation in clinical trials using groups of patients the statistical power is dependent on sample size, variability of responses, magnitude of the differential treatment effect and the level of statistical significance. In addition, the randomization procedure is of importance and power estimations show that a pairwise random allocation of treatment periods is more powerful than an unrestricted randomization. Since a single subject trial is a time consuming approach, the total number of treatment periods, the sample size, is restricted in order to make such trials feasible. Accordingly, less rigorous statistical requirements and power must be accepted. The consequence is an increased risk of both Type I and II errors. However, in comparison with the trial and error approach frequently applied in clinical practice, the controlled single subject trial may improve the certainty of therapeutic decisions in the individual patient.
Clinical Trials as Topic↗
Relationship between endoscopic hiatus hernia and gastroesophageal reflux symptoms.
Little is known about the relationship between hiatus hernia (HH) and gastroesophageal reflux symptoms (GERS). Nine hundred and thirty patients submitted to gastroscopy because of symptoms completed a self-administered questionnaire. Fourteen per cent showed esophagitis (ES) and 17% HH. Forty-nine per cent of the patients with HH had endoscopic ES, and 60% of those with ES had HH. The severity of ES was dependent (p less than 0.05) on both the presence and the size of HH. After exclusion of patients with peptic ulcer and malignancy, patients with and without HH and ES were compared with regard to the presence of single symptoms and a weighted GERS score based on symptoms proven to be typical for ES. Only borderline differences were found between patients with ES and HH and those with ES and no HH. The former group, however, presented with significantly (p less than 0.001) more GERS than the patients with HH only. Nevertheless, the patients with HH as the only pathologic finding had significantly (p less than 0.01) more GERS than the patients with no major endoscopic abnormality. This study indicates a close association between HH and gastroesophageal reflux disease and supports the clinical significance of an endoscopically detected HH.
Adult↗
The symptomatic effect of 1-day treatment periods with cimetidine in dyspepsia. Combined results from randomized, controlled, single-subject trials.
Before endoscopy a double-blind, randomized, controlled, single-subject trial comparing the symptomatic effect of 1-day treatment periods with cimetidine and placebo was conducted in patients with dyspepsia. Results from 339 patients were analysed. The trial lasted 12 days and consisted of 6 treatment days with 400 mg cimetidine three times daily and 6 days with placebo three times daily. The order of the treatments was randomized within six pairs, and a randomization test based on daily measures of global symptoms provided individual p values. Aggregation of the measures from all subjects showed that cimetidine alleviated the symptoms significantly better than placebo in peptic ulcer disease (PUD) (p less than 0.0001), oesophagitis (p less than 0.001), and non-ulcer dyspepsia (NUD) (p less than 0.0001). Twenty-seven per cent of the patients with PUD, 26% of those with oesophagitis, and 12% of the patients with NUD obtained individual p values of less than 0.10 and were defined as responders. The best predictors of the response to cimetidine in NUD were age above 40 years, heartburn or acid regurgitations being the worst symptom, and night pains relieved by food, milk, or antacids. In conclusion, the applied single-subject trial confirmed the overall symptomatic effect of cimetidine in dyspepsia and identified individual responders among patients with NUD with a clinically reasonable profile. The low proportion of responders among patients with PUD or oesophagitis suggests that the model has a low sensitivity for identification of individual responders and that the single-subject trial design in dyspepsia needs further refinement.
Adult↗
The controlled single subject trial.
Randomized controlled trials in single subjects ('N of 1 RCT') are double-blind, multi crossover trials in which the effects of two or more treatments are compared within one individual. The aim is to provide a controlled assessment of the efficacy of a new drug in a specific patient. Suitable diseases for single subject trials are particularly those which significantly impair the quality of life and in which there are uncertain treatment effects. Appropriate drugs should have a prompt action, a minimum of carry-over effect, and no side-effects. The trial design is determined by the length, number, and order of successive treatment periods, the outcome measures, and the statistical requirements. Each of these elements may be altered and tailored to the clinical entity and drug(s) applied, thus, providing a large potential for design options.
Double-Blind Method↗
Combined single subject trials.
Randomized controlled single subject trials are designed as multiple crossovers between the treatments to be compared. Results from such independent trials may be combined and integrated for the purpose of extending the conclusions beyond the single subject. Unlike the conventional crossover group trial, the primary goal of the combined single subject study is not to demonstrate an overall clinical benefit of a drug, but to indicate the features typical for drug responders. The external validity of combined single subject trials depends on the same prerequisites as are employed in group trials: strict entry criteria, uniform treatment procedures, consensus targets for outcome measures, and acceptable statistical tests. In clinical research the main role of combined single subject trials should be to elucidate new insight and generate hypotheses that could optimize the design of subsequent group trials.
Data Interpretation, Statistical↗
Statistical aspects of controlled single subject trials.
Randomized controlled trials in groups and single subjects differ in several statistical aspects. In group trials the experimental unit is a randomly selected subject from a predefined population and this subject is randomly assigned to a treatment. Outcome is confined to average effects which can be generalized to the specific population, but which do not necessarily apply to individual persons. In single subject trials the experimental unit is a treatment period and each treatment period is randomly allocated in a multiple cross-over sequence of periods. The single subject is only representative of itself, but similar responses in corresponding single subject trials may justify careful extrapolation of the results. Single subject trials have a high risk of Type II errors. However, the randomization procedure chosen and the type of statistical test applied may enhance the statistical power of such trials. Internal validity depends on modeling the trial design to the clinical features, drug properties and statistical requirements, while reliability is determined by the reproducibility of the trial response.
Humans↗
The predictive value of history in dyspepsia.
Symptomatic patients referred to an open-access upper gastrointestinal endoscopy completed a detailed, self-administered questionnaire aimed at assessing the predictive value of history in dyspepsia. Nine hundred and thirty patients were suitable for analysis. Of these, 29% were found to have organic dyspepsia. A substantial overlap of symptoms and demographic data was found among the various endoscopic diagnoses. Discriminating variables were identified by stepwise logistic regression analysis and included in predictive score models. Pain relieved by antacids, age above 40 years, previous peptic ulcer disease, male sex, symptoms provoked by berries, and night pain relieved by antacids and food were found to predict organic dyspepsia with a sensitivity and specificity of approximately 70%, when applied on the observed material. Similar probabilities were found for score models of peptic ulcer and esophagitis. In general, the low prevalence of organic diseases resulted in low positive and high negative predictive values. Accordingly, the main impact of the predictive models may be to reduce the number of negative endoscopies rather than to predict a precise diagnosis. Independent of disease category and age, 41% of the subjects expressed a fear of malignancy, emphasizing the value of reassurance from a negative endoscopy.
Adult↗