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Biomedical subjects

U Ferner

Publications and source records attributed to U Ferner.

At least 19 recordsLinked to original sources
PubMed1992

Active control equivalence trials: some methodological aspects.

The therapeutic efficacy of an investigational new drug is best demonstrated in clinical trials against a placebo control. However, ethical requirements increasingly preclude the use of an inactive control substance as a treatment alternative, as clinical testing to compare the effects of active treatments, has become more frequent. The statistical evaluation and interpretation of these trials is complex and requires the demonstration of 'equivalence' or 'at-least equivalence' between the experimental drug and a comparable standard therapy. The design of controlled clinical trials to compare the effects of moclobemide, a new and selective monoamine oxidase-A inhibitor, with those of standard tricyclic antidepressant drugs involved the refinement of selection strategies, formulation of hypotheses, means of statistical analysis and clinical interpretation.

Antidepressive Agents↗
PubMed1990

[Biochemical aspects of the evaluation of fixed drug combinations].

Various disciplines have to contribute to the general problem of the evaluation of fixed dose combination drugs, as for instance (clinical) pharmacology, biometry, scientific drug regulations and public health officials. The EC guideline 75/318/EWG and its eludications as well as the German "Arzneimittelprüfrichtlinien" of Dec. 14, 1989 (as referred to in the "Arzneimittelgesetz" of 1986) required that such issues concerning fixed dosage combination drugs must be considered and taken into account. In this framework it is the responsibility of biometry to both to guarantee the use of a valid study design to assure interpretation of the results and to quantify the reliability of pharmacological and clinical considerations. The following paper is concerned with biometrical aspects of the combination drug problem. Basic considerations from a clinical or a pharmacological point of view with respect to the question of whether fixed combination drugs are reasonable or not are not discussed. To support the use of combinations of drugs, a central argument is the improvement of the benefit risk relation compared with that of an adequate monotherapy. Beyond this the fixed combination drugs require additional arguments regarding the enhencement of the safety or the simplicity of the therapy fixing the ratio. It follows that fixed combination drugs have to be supported twice, first with respect to the combination itself, and second with respect to the fixed mixing ratio of its components. The biometrical aspects of the assessment of the gains from (fixed) drug combinations are related to the kind of benefit/risk improvement that is expected. In the first section we discuss some possible types of benefit and risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[Acral rewarming. I: "Normal data" of a healthy adult population].

The acral rewarming test was investigated in 285 healthy subjects (mean age: 44.1; 20-71) to establish "normal" or reference values as a basis for interpreting patient data. The study was disposed in a manner to look also for possible diurnal and seasonal variations of the rewarming parameters. Healthy controls show a considerable interindividual variability in the speed and the pattern of acral rewarming, with a striking bimodal distribution of the individual values. This variability is mainly due to the factors "season" and "gender", while "age" and "daytime" are more related to basal finger temperature as to the rate of rewarming. According to these findings seasonal variations must necessarily be included in the definition of normal reference values of the rewarming test. In the healthy subjects neither personality characteristics (Freiburger personality inventory) nor the individual's psycho-social situation (Life Event questionnaire) and "depressivity" (Beck inventory) correlate with rewarming parameters. However, momentary "fatigue" (Visual Analogue Scale) correlates negatively and the sum of "somatic complaints" positively with acral rewarming time. The issue of variability in normative data is discussed with reference to clinical applications of the rewarming test in part II.

Adult↗
PubMed1983

Confirmatory and exploratory analysis applied to pharmaco-EEG and related study data: contradiction or useful enrichment?

Besides hypothesis testing, which should be done as sparingly as possible, the measured or observed data should be described as extensively as possible. The traditional reliance on profiles of the mean responses may neglect useful information, and such profiles may also be misleading. With the aid of exploratory data analysis, different aspects of the structure of a data set can be considered. 'Data snooping' may discover coherences, non-trivial structures and peculiarities, which lead to a new hypothesis or to new mathematical-statistical models. It is, in our opinion, a necessity to consider exploratory and confirmatory data analyses in conjunction. This will be illustrated by examples taken from pharmaco-EEG studies.

Aged↗
PubMed1977

[Statistical aspects in planning psychotropic drug trials (author's transl)].

It has become virtually unthinkable to objectively judge trials of comparisons without statistical inference. For studies involving psychopharmaceuticals the requirements have especially grown, since variations of efficacy are difficult to differentiate and objectivate. The basic principles of statistical planning must be applied to studies with psychopharmaceuticals. On the basis of these general principles the relevant points of the clinical and statistical models and their relationship to one another are discussed. Special aspects of the study objectives, the clinical model, the medical trial plan, the statistical model and design, the execution of the trials, statistical evaluation and its interpretation are presented. The setting up of hypotheses, balancing and maintenance of factors of disturbances, sample sizes, randomizing techniques and the confrontation of clinical relevance with statistical significance are some of the important points discussed.

Clinical Trials as Topic↗