This invited editorial contextualizes a paper published in Annals of Internal Medicine. The paper demonstrates that the saline suppression test—a guideline-recommended confirmatory test that is often required prior to making a formal diagnosis of primary aldosteronism—has low sensitivity, specificity, and positive and negative predictive values.
The editorial explains that confirmatory testing relies heavily on high specificity, a characteristic typically inherent to the test itself. Nonetheless, as guidelines broaden the indications for screening for primary aldosteronism and the pretest probability of primary aldosteronism lowers, the test is likely to perform even worse with regard to positive and negative predictive values. Confirmatory testing for primary aldosteronism has not been systematically demonstrated to be able to serve its intended purpose. These tests have high false negative rates, and can actually prevent many people from receiving appropriate treatment.