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Updated: Jul 11, 2026

A Clinical Trial Assessing the Safety, Efficacy, and Delivery of Olive-Oil-Based Three-Chamber Bags for Parenteral Nutrition
Published on: September 20, 2019
Validity of randomized clinical trials in gastroenterology from 1964-2000
Lise L Kjaergard1, Sarah L Frederiksen, Christian Gluud
1The Cochrane Hepato-Biliary Group, Copenhagen Trial Unit, Center for Clinical Intervention Research, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
Background & Aims:
The internal validity of clinical trials depends on the adequacy of the reported methodological quality. We assessed the methodological quality of all 383 randomized clinical trials published in GASTROENTEROLOGY as original articles from 1964 to 2000.
Methods:
The methodological quality (randomization and blinding), sample size, publication year, and disease area were extracted from each trial. Changes during the study period were analyzed by analysis of variance with adjustments for potential confounders.
Results:
Forty-two percent of all trials reported adequate generation of the allocation sequence, 39% reported adequate allocation concealment, and 62% were double blind. The reported methodological quality improved significantly in the mid-1990s.
Conclusions:
The present study shows a positive development, but the reported methodological quality of trials can still be improved.
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