Visit-to-visit variability (VVV) of systolic blood pressure (SBP) has been associated with an increased risk for stroke, coronary heart disease (CHD), and mortality in several studies, but few randomized trials have compared VVV of SBP across drug classes. Therefore, Dr. Paul Muntner, professor, and Dr. Emily B. Levitan, assistant professor, in the department of epidemiology at the University of Alabama at Birmingham, compared VVV of SBP among 24,004 participants randomized to chlorthalidone, amlodipine, or lisinopril in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT).