Scandinavian journal of gastroenterology. Supplement
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Scand. J. Gastroenterol. Suppl. · Jan 1988
Comparative StudySingle case studies in clinical trials.
The single case design offers an interesting alternative to standard methods of performing clinical trials. The opinion of the workshop members was that single case trials would be particularly useful in studies of rare diseases and in studies aimed at generation of hypothesis rather than testing of hypotheses. The single case design was considered to require smaller patient materials than ordinary methods in order to arrive at a valid conclusion about therapeutic effect. Dose ranging (Phase II) studies and studies of heterogenous patient populations were also discussed as possible areas of application for the single case design.
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In these speculations of the future in gastro-esophageal reflux a hope is expressed that gastro-esophageal reflux disease is accepted as a separate entity. Treatment and diagnosis should not be confused with those of ulcer disease. ⋯ The problem is mainly a leaking valve. Furthermore, the expression reflux like dyspepsia should be used when esophagitis or gastro-esophageal reflux disease is not established by endoscopy or pH-monitoring.
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Scand. J. Gastroenterol. Suppl. · Jan 1988
Comparative StudyExperience with a multi crossover model in dyspepsia.
A multi cross over model (MCOM) has been designed for single case studies. The model which is only partly randomized, implies regular interchanges between treatment periods with active drug and placebo. ⋯ The advantages of the single case approach and the impact of the MCOM is illustrated by the results from a study of the effect of cimetidine in non ulcer dyspepsia. Although there are several statistical objections to the model, the results from the study are reasonable and demonstrate a small degree of violence of preassumptions.
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Scand. J. Gastroenterol. Suppl. · Jan 1988
Comparative StudyStatistical issues in studies of individual response.
We consider intensive studies of individual response to therapy in a controlled experiment. It is helpful to distinguish between strict 'N = 1' studies, which are pragmatic trials intended to draw conclusions concerning only the patient under consideration, and 'N much greater than 1' studies, which are explanatory trials intended to make more general statements about a treatment with highly variable response, for which aggregate measures of effect on groups are inappropriate. Issues of design, measurement, and statistical significance are discussed, and the rule of permutation tests emphasised. Three published examples are used as illustrations.