Article type
Year
Abstract
Introduction: The ISTH (International Society on Thrombosis and Haemostatis) prospective multicentre clinical trials register was first published in 1975, and is the oldest register of this type in existence. The efficacy of this register has never been assessed.
Objective: To assess the efficacy of a prospective clinical trials register from 1974 to 1989.
Methods: The evaluation was limited to trials assessing thrombolytic therapy in acute myocardial infarction. Since there is a lapse between the planing phase and publication of a clinical trial, the literature handsearching and electronic searching was done from 1974 to 1993. The INDEX MEDICUS, and MEDLINE were used for direct searching, and indirect searching was performed using the references cited in trial reports identified. The efficacy of the register was defined as the number of trials registered as a percentage of the published trials identified.
Results: The INDEX MEDICUS search identified 113 multicentre clinical trials assessing thrombolytic therapy in acute myocardial infarction, of which only 43 (38%) had been registered in the ISTH register. The MEDLINE search identified 78 trials of which 32 (41%) had been registered in the ISTH register. The indirect searching identified 90 trials of which 34 (38%) had been registered. The combination of the three methods identified 156 trials of which 58 (37%) had been registered. 14 trials registered in the ISTH register were not found by any search technique. The 11 investigators responsible for these trials were contacted by letter and we found out that two trials had never started. Information for 3 other trials was unclear, the investigators for 3 other trials had moved (letters returned) and no news was obtained about the other letters.
Discussion: The ISTH register is far from exhaustive. Many explanations exist for this, one important one being the fact that registration is on a voluntary-basis, and while many investigators are happy to supply information about planned and on-going clinical trials, this is not true for all. This situation will only improve if registration becomes mandatory before clinical trials can be initiated.
Objective: To assess the efficacy of a prospective clinical trials register from 1974 to 1989.
Methods: The evaluation was limited to trials assessing thrombolytic therapy in acute myocardial infarction. Since there is a lapse between the planing phase and publication of a clinical trial, the literature handsearching and electronic searching was done from 1974 to 1993. The INDEX MEDICUS, and MEDLINE were used for direct searching, and indirect searching was performed using the references cited in trial reports identified. The efficacy of the register was defined as the number of trials registered as a percentage of the published trials identified.
Results: The INDEX MEDICUS search identified 113 multicentre clinical trials assessing thrombolytic therapy in acute myocardial infarction, of which only 43 (38%) had been registered in the ISTH register. The MEDLINE search identified 78 trials of which 32 (41%) had been registered in the ISTH register. The indirect searching identified 90 trials of which 34 (38%) had been registered. The combination of the three methods identified 156 trials of which 58 (37%) had been registered. 14 trials registered in the ISTH register were not found by any search technique. The 11 investigators responsible for these trials were contacted by letter and we found out that two trials had never started. Information for 3 other trials was unclear, the investigators for 3 other trials had moved (letters returned) and no news was obtained about the other letters.
Discussion: The ISTH register is far from exhaustive. Many explanations exist for this, one important one being the fact that registration is on a voluntary-basis, and while many investigators are happy to supply information about planned and on-going clinical trials, this is not true for all. This situation will only improve if registration becomes mandatory before clinical trials can be initiated.