Article type
Year
Abstract
Background:
A significant proportion of randomised controlled trials (RCTs) are never published or their results are disseminated only to some extent.
Objectives:
To determine the rate of publication of RCTs on oncology authorized in Spain between 1999 and 2003, to analyze the determinants of publication and location bias, and to estimate the bibliometric characteristics of the journals in which these studies were published.
Methods:
All RCTs identified during the study period were identified (N = 303). Subsequently, all publications derived from these studies were searched for in electronic databases. When necessary, the sponsor and principal investigator in Spain were contacted. Bibliometric indicators were located (to March 2013). A descriptive univariate analysis and logistic regression was performed.
Results:
We identified 152 publications out of a total of 303 RCTs on oncologic drugs, equivalent to a 50.2% publication rate. Spanish studies accounted for 14.5% (22/152) of these publications, whereas 85.5% (13/152) were international studies. Published studies were most likely international (P = 0.00) and sponsored by pharmaceutical companies (P = 0.01). Variables significantly associated with publication of results were promoter (OR 3.47, 95% confidence interval (CI) 1.65 to 7.29) and scope of the study (OR 3.77, 95% CI 1.73 to 8.23), with industry-sponsored studies and national-level studies being less likely to be published.
RCTs with results that proved the hypothesis of the study were published in journals with a higher impact factor (P = 0.01). All the publications identified were international journals, 40.60% of which focused specifically in the field of oncology. For all publications, the average time from Spanish Agency for Medicines and Medical Devices approval to publication was 6.21 years (± 2.43) with a median of six years (range 2 to 13).
Conclusions:
National studies (many of them closed prematurely due to lack of recruitment) and those promoted by the pharmaceutical industry were at an increased risk of not being published. Some initiatives, such as public registries and the AllTrials Campaign promote transparency.
A significant proportion of randomised controlled trials (RCTs) are never published or their results are disseminated only to some extent.
Objectives:
To determine the rate of publication of RCTs on oncology authorized in Spain between 1999 and 2003, to analyze the determinants of publication and location bias, and to estimate the bibliometric characteristics of the journals in which these studies were published.
Methods:
All RCTs identified during the study period were identified (N = 303). Subsequently, all publications derived from these studies were searched for in electronic databases. When necessary, the sponsor and principal investigator in Spain were contacted. Bibliometric indicators were located (to March 2013). A descriptive univariate analysis and logistic regression was performed.
Results:
We identified 152 publications out of a total of 303 RCTs on oncologic drugs, equivalent to a 50.2% publication rate. Spanish studies accounted for 14.5% (22/152) of these publications, whereas 85.5% (13/152) were international studies. Published studies were most likely international (P = 0.00) and sponsored by pharmaceutical companies (P = 0.01). Variables significantly associated with publication of results were promoter (OR 3.47, 95% confidence interval (CI) 1.65 to 7.29) and scope of the study (OR 3.77, 95% CI 1.73 to 8.23), with industry-sponsored studies and national-level studies being less likely to be published.
RCTs with results that proved the hypothesis of the study were published in journals with a higher impact factor (P = 0.01). All the publications identified were international journals, 40.60% of which focused specifically in the field of oncology. For all publications, the average time from Spanish Agency for Medicines and Medical Devices approval to publication was 6.21 years (± 2.43) with a median of six years (range 2 to 13).
Conclusions:
National studies (many of them closed prematurely due to lack of recruitment) and those promoted by the pharmaceutical industry were at an increased risk of not being published. Some initiatives, such as public registries and the AllTrials Campaign promote transparency.