Clinical InvestigationCardiovascular EpidemiologyPrevalence, characteristics, and predictors of early termination of cardiovascular clinical trials due to low recruitment: Insights from the ClinicalTrials.gov registry
Section snippets
ClinicalTrials.gov
The methods and quality assurance strategies used by ClinicalTrials.gov to register trials have been described in detail previously.5, 6 ClinicalTrials.gov was developed and is maintained by the National Library of Medicine on behalf of the National Institutes of Health (NIH). ClinicalTrials.gov uses a Web-based system to facilitate registration of clinical trials by the study sponsor or the principal investigator and includes both mandatory and optional data elements.7
Eligibility criteria and search strategy
We searched the
Results
Our search strategy retrieved 7,042 trials, from which we were able to identify 6,279 studies that met the inclusion criteria of cardiovascular clinical trials registered in ClinicalTrials.gov between February 29, 2000, and January 17, 2013. From the eligible trials, 5,595 (89.1%) were classified as completed and 684 (10.9%) trials as terminated.
From the total of terminated trials, 165 trials (24.1%) did not report the reason for their early termination. After performing a Medline search, we
Discussion
Our study showed that, among a contemporary cohort of cardiovascular clinical trials registered in ClinicalTrials.gov, more than 10% were terminated prematurely. The most common reason for early termination was lower than expected recruitment rates. Factors associated with lower risk of early termination due to low recruitment were funding by the NIH or other US federal agencies as well as trials assessing behavioral or dietary interventions and those with a single-arm design. On the other
Disclosures
Sources of funding: No extramural funding was used to support this work.
Acknowledgements
We thank Peter Hoffmann of the Duke Clinical Research Institute for his editorial contribution to this manuscript.
References (24)
Compressed mortality file: underlying cause of death, 1979 to 2005
- et al.
The effects of an open design on trial participant recruitment, compliance and retention—a randomized controlled trial comparison with a blinded, placebo-controlled design
Clin Trials
(2004) - et al.
Characteristics of clinical trials registered in ClinicalTrials.gov, 2007-2010
JAMA
(2012) - et al.
The ClinicalTrials.gov results database—update and key issues
N Engl J Med
(2011) - et al.
Trial registration at ClinicalTrials.gov between May and October 2005
N Engl J Med
(2005) - et al.
Issues in the registration of clinical trials
JAMA
(2007) ClinicalTrials.gov protocol Data Element Definitions (DRAFT)
MeSH terms: cardiovascular diseases
R: a language and environment for statistical computing
Clinical Trials Transformation Initiative Web site
Logistic regression using the SAS system: theory and application
Applied logistic regression
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Charles Maynard, PhD, served as guest editor for this article.