Article type
Year
Abstract
Objective: Determining the usefulness of making e-mail contact with authors of clinical trials and literature reviews found in MEDLINE to identify relevant ongoing or unpublished RCTs or those published in non-indexed journals to facilitate systematic review.
Materials and Methods: A structured search made using the OVID platform between January 1999 and June 2003 using a filter frequently employed for detecting Randomized Controlled Trials (RCT) for systematic reviews found 517,209 references on many different topics. A random sample of clinical trials (in any phase) and reviews was selected for each year bearing in mind that around 30% of the articles provided an e-mail for contacting the corresponding author. After a pilot test had been carried out, a questionnaire was sent to 525 e-mails on two occasions and return e-mails were received during the next 4 weeks. Those RCTs obtained through the questionnaire were sought in the MEDLINE (1966-2003), EMBASE (1974-2003), Cochrane Library (Cochrane Controlled Trials Register), LILACS and www.clinicaltrials.gov databases.
Results: 105 (20%) of the 525 e-mails sent did not reach their determined destination and 40 replies were received to the questionnaire (7.6%). 40% of the authors stated that they were currently participating in 28 ongoing RCT; five authors had included their RCTs in ongoing register databases. 12 unpublished RCTs or published in a non-indexed journal were found; two of them were found in the Cochrane library s register of clinical trials. The most frequently given reasons for not publishing were: lack of time for finalising the statistical analysis and preparing the manuscript, contractual obligations with the pharmaceutical industry, the material had been the subject of an undergraduate thesis, methodological errors in designing the study and lack of statistical power, editorial rejection and loss of information. 53% of the authors replied that they were willing to send information concerning unpublished clinical studies. 29.6% of those involved in a systematic review were not willing to send data regarding ongoing studies whilst 65% of those involved in a clinical trial would do so. The disposition to send data about unpublished studies which could be useful in designing systematic reviews became reduced by half when the authors had received previous e-mails requesting information.
Conclusion: Using the e-mails of all those authors who detect the search in databases could contribute towards detecting potentially relevant ongoing or unpublished RCTs enabling rapid, straightforward, low-cost systematic review.
Materials and Methods: A structured search made using the OVID platform between January 1999 and June 2003 using a filter frequently employed for detecting Randomized Controlled Trials (RCT) for systematic reviews found 517,209 references on many different topics. A random sample of clinical trials (in any phase) and reviews was selected for each year bearing in mind that around 30% of the articles provided an e-mail for contacting the corresponding author. After a pilot test had been carried out, a questionnaire was sent to 525 e-mails on two occasions and return e-mails were received during the next 4 weeks. Those RCTs obtained through the questionnaire were sought in the MEDLINE (1966-2003), EMBASE (1974-2003), Cochrane Library (Cochrane Controlled Trials Register), LILACS and www.clinicaltrials.gov databases.
Results: 105 (20%) of the 525 e-mails sent did not reach their determined destination and 40 replies were received to the questionnaire (7.6%). 40% of the authors stated that they were currently participating in 28 ongoing RCT; five authors had included their RCTs in ongoing register databases. 12 unpublished RCTs or published in a non-indexed journal were found; two of them were found in the Cochrane library s register of clinical trials. The most frequently given reasons for not publishing were: lack of time for finalising the statistical analysis and preparing the manuscript, contractual obligations with the pharmaceutical industry, the material had been the subject of an undergraduate thesis, methodological errors in designing the study and lack of statistical power, editorial rejection and loss of information. 53% of the authors replied that they were willing to send information concerning unpublished clinical studies. 29.6% of those involved in a systematic review were not willing to send data regarding ongoing studies whilst 65% of those involved in a clinical trial would do so. The disposition to send data about unpublished studies which could be useful in designing systematic reviews became reduced by half when the authors had received previous e-mails requesting information.
Conclusion: Using the e-mails of all those authors who detect the search in databases could contribute towards detecting potentially relevant ongoing or unpublished RCTs enabling rapid, straightforward, low-cost systematic review.