Data and Salt

February 21st, 2005

Posted by: Roger Pielke, Jr.

Nature reported last week that a lawsuit is underway to force researchers to reveal the original data that was used in a study that was used to justify a recommendation that all Americans cut back on their salt intake.

“As early as this summer, for example, a US Court of Appeals will judge a plea from the Virginia-based Salt Institute, which represents salt producers. The institute wants direct access to the data behind a study that linked salt consumption to high blood pressure. The trial, funded by the National Heart, Lung, and Blood Institute (NHLBI), studied the impact of dietary sodium intake on blood pressure and the results were published in The New England Journal of Medicine, Annals of Internal Medicine and The American Journal of Cardiology. They showed that reducing dietary sodium lowers blood pressure in most people, and this led the government to recommend that Americans consume less salt. Researchers in the trial say that they have released all the data the Salt Institute could want or need — and that it is misusing the act. “It is trying to slice and dice the data set so it finds a group that seems not to have a blood pressure that’s responsive to reduction in salt,” says Lawrence Appel, a physician at Johns Hopkins School of Public Health in Baltimore, Maryland, and one of the trial’s principal investigators. “That’s blatantly inconsistent with a scientific approach to analysing clinical data.” Last month, the Salt Institute and the US Chamber of Commerce asked the Fourth Circuit Court of Appeals to overturn a decision by a lower court in Virginia. That court had ruled that the NHLBI was within its rights in refusing to release the data that had been requested.”

The lawsuit is being filed under the Data Quality Act (which we discussed here). One of the provisions of the DQA, according to a 2003 news article in Science is that, “According to the White House Office of Management and Budget’s interpretation of the act, which took effect last October, agencies that promulgate “influential” results may have to provide enough data and methods for a “qualified member of the public” to conduct a reanalysis.”

The salt case raises some important questions about what is popularly called the “democratization of science.” Arizona State’s David Guston provides a definition,

“Democratizing science does not mean settling questions about Nature by plebiscite, any more than democratizing politics means setting the prime rate by referendum. What democratization does mean, in science as elsewhere, is creating institutions and practices that fully incorporate principles of accessibility, transparency, and accountability.”

Who should have access to data, analytical tools and results of publicly funded research? And particularly that research which is used to justify important decisions?

These are important questions of science policy and the salt case will go some way towards clarifying policy for (lack of) transparency and (non) disclosure in the scientific enterprise. However it turns out, one point seems clear. Demands for transparency and disclosure will increase with the degree to which important decisions are justified based on the results of scientific analyses. For researchers doing policy-relevant work, it is probably a good idea to keep good records.

3 Responses to “Data and Salt”

  1. William Connolley Says:

    “Democratizing science does not mean settling questions about Nature by plebiscite, any more than democratizing politics means setting the prime rate by referendum”.

    That might be a useful basis for comparison. Are the data used for setting the prime rate made available to the sort of detail that is proposed for the science data? In the UK, the minutes of the monetary policy committee are relseased, delayed, but I’m less sure that the background info is.

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  3. Roger A. Pielke, Jr. Says:

    William- Thanks for your comment. This would make for a great thesis project for an aspiring science policy analyst. It could even involve a comparison across countries. It looks to me like the U.S. Federal Reserve makes all of its economic data available here:

    ——————– It does have some exceptions to what is released:


    ——————– The original studies that produce the data are here:

    And here:


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  5. WilliamConnolley Says:

    It looks like you’re right. I followed one link at random – household survey data – and it offered to let me download the raw data. How does science fare? A lot of the IPCC TAR model data is available from the DDC: In many cases you can’t have the model code (can you get the treasury model code?) but you can have the output. There is even some AR4 data there. An openness intercomparison would be interesting (my other intercomparison project for an interested party would be: which are more reliable, climate models or economic models?).