Quality of Clinical Trials — A Concern of Three Decades

The purpose of this article is to summarize reviews on the quality of clinical trials. Altogether 29 reviews were found. Most clinical trials were judged to be uncontrolled or poorly controlled and/or otherwise poor. To study any change over time, reviews based on reports published 1943—1959, 1960—67, and 1968—77 were considered. The proportion of controlled trials was higher in 1943—59 than in 1968—77. The proportion of trials defined as »good« was lowest in the period 1960—1967. Since the material and definitions varied from one review to the other, the results should be interpreted to reflect the reviewers’ concern about quality rather than the actual quality of the trials themselves. In fact, in most reviews, in which the criteria and material used over time were comparable, the quality of trials had improved. But various factors guarantee that worries about the quality of clinical trials will continue.

Zweck dieser Arbeit ist es, Übersichtsartikel über die Qualität klinischer Therapiestudien zusammenzustellen. Insgesamt 29 Übersichtsartikel wurden gefunden. Die meisten klinischen Therapiestudien wurden als unkontrolliert oder schlecht kontrolliert und/oder in sonstiger Hinsicht dürftig beurteilt. Um zeitliche Veränderungen festzustellen, wurden die Übersichtsartikel nach den Berichtszeiträumen 1943—1959, 1960—1967 und 1968—1977 differenziert. Der Anteil kontrollierter Studien war im Zeitraum 1943—1959 höher als 1968—1977. Der Anteil von als »gut« bezeichneten Studien war am niedrigsten im Zeitraum 1960—1967. Da Material und Definitionen der verschiedenen Übersichtsartikel sehr unterschiedlich waren, spiegeln deren Ergebnisse eher die Besorgnis des jeweiligen Verfassers über die Qualität wider als die tatsächliche Qualität der Studien selbst. In der Tat geht aus den meisten Übersichtsartikeln, bei denen die Kriterien und das über den Beobachtungszeitraum benutzte Material vergleichbar waren, hervor, daß die Qualität der Studien besser wurde. Verschiedene Faktoren lassen es jedoch als sicher erscheinen, daß Besorgnisse über die Qualität klinischer Therapiestudien auch in Zukunft anhalten werden.

Key-Words

Clinical Trials - Evaluation Study - Review

Schlüssel-Wörter

Klinische Therapiestudien - Auswertungsstudie - Übersichtsartikel

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