Medical journals may urge researchers to make raw study data available publicly, but many researchers are still not doing so, according to recent study in PLoS One, which reviewed 351 paper from 50 medical journals that have the highest impact. The review found a wide variation in policies for sharing data and how researchers follow these policies.
And as Nature notes, the results come amid a big push to make such study data available, not only to facilitate additional research, but also mitigate fraud and error. To cope, the study authors suggest more journals should adopt specific data-sharing policies and procedures are needed to ensure that existing policies are consistently followed by researchers and published findings are easily reproducible.
As to the findings, the study found that 22 of the 50 journals required public sharing of specific raw data as a condition of publication, and another 22 encourage data sharing without any binding instructions. The remaining six journals offered no instruction. The researchers then examined the first 10 papers published in each of the 50 journals in 2009.
They found that 149 were not subject to any data-sharing policy. Of the remaining 351 papers, 208, or 59 percent, did not fully adhere to data availability instructions; most common was not publicly depositing microarray data. The other 143 papers that did follow data availability instructions did so by publicly depositing only the specific data type as required, making a statement of willingness to share, or actually sharing all the primary data.
"The current state is not optimal," John Ioannidis, the lead author and an expert in data reproducibility at Stanford University School of Medicine in California, told Nature. "Some journals have pretty good policies and some of the papers adhere to these, but there is plenty of room for improvement".
The study also found that researchers rarely volunteer data. Of the 500 papers examined, only 47 had their full primary data sets - as opposed to just the raw data requested by the journals - publicly available. None of the papers published in journals without data-sharing policies deposited their full set of raw data online, Nature adds.
Why is there such reluctance? Journal editors may not want to insist on introducing or enforcing data-sharing policies if this would discourage submissions (here is the PLoS study).
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