Use of plasma aldosterone concentration-to-plasma renin activity ratio as a screening test for primary aldosteronism: A systematic review of the literature

The aldosterone-renin ratio is widely used to screen for primary aldosteronism. We conducted a systematic review of the literature to establish the test characteristics (sensitivity, specificity, likelihood ratios at different cutoff values) of the aldosterone-renin ratio used in screening for primary aldosteronism in subjects with presumed essential hypertension. We searched Medline, EMBASE, and Current Contents databases, bibliographies of retrieved papers, and personal files for all reports published from January 1966 to October 2001. We consulted experts to identify additional published and unpublished reports. We included prospective studies of the ratio as a screening test for primary aldosteronism, without applying language or data availability restrictions. We excluded retrospective studies, case reports, and duplicate or preliminary reports. Working independently, we selected the articles, assessed their quality, and extracted their data. Data extracted included sample size and care setting, description of the testing conditions, description of the confirmatory tests, and the test characteristics of the ratio (sensitivity, specificity, likelihood ratios at different cutoff values). This review includes 16 studies with 3136 participants. None of the studies evaluated the aldosterone-renin ratio and the reference standard independently of each other; only two studies evaluated patients who had a "negative" ratio with the reference standard. Only 16.7% of the subjects had both the ratio and the confirmatory test performed. Ratio cutoff values ranged from 200 to 2774 pmol/L per ng/mL per hour. None of the studies provided valid estimates of the aldosterone-renin ratio test characteristics. There are no published valid estimates of the test characteristics of the aldosterone-renin ratio when used as a screening test for primary aldosteronism in patients with presumed essential hypertension.