
Coffee and the Heart: Is caffeine a trigger for AFib?
Normal Curves: Sexy Science, Serious StatisticsShow Notes
Does coffee trigger atrial fibrillation — or have doctors been warning people away from caffeine without strong evidence? We dig into two recent randomized clinical trials testing whether caffeinated coffee causes dangerous heart rhythm problems. Along the way, we talk about AFib, survival analysis, intention-to-treat versus as-treated analyses, and one surprisingly elaborate effort to catch clinical trial cheaters with receipts and geolocation tracking. We also explore how a pope may have fueled a European coffee resurgence, why plants make caffeine, and how a game show competition explains hazard ratios.
Statistical topics adherence and compliance as-treated analysis confidence intervals Cox proportional hazards regression hazard ratios intention-to-treat analysis micro-randomization multiple testing PICOT pre-registration primary vs secondary outcomes randomized clinical trials sensitivity analyses SMART framework survival analysis
Methodological morals “Never trust conventional wisdom until you see the randomized controlled trial.” “Trust your participants, but design the study so that they can be honest about their dishonesty.”
References Harrington D, D'Agostino RB Sr, Gatsonis C, et al. New Guidelines for Statistical Reporting in the Journal. N Engl J Med. 2019;381(3):285-286. doi:10.1056/NEJMe1906559 Marcus GM, Rosenthal DG, Nah G, et al. Acute Effects of Coffee Consumption on Health among Ambulatory Adults. N Engl J Med. 2023;388(12):1092-1100. doi:10.1056/NEJMoa2204737 Wong CX, Cheung CC, Montenegro G, et al. Caffeinated Coffee Consumption or Abstinence to Reduce Atrial Fibrillation: The DECAF Randomized Clinical Trial. JAMA. 2026;335(4):317-325. doi:10.1001/jama.2025.21056 @MarcKatzMD’s short video The Pitt- atrial fibrillation cardioversion scene
Kristin and Regina’s online courses: Demystifying Data: A Modern Approach to Statistical Understanding Clinical Trials: Design, Strategy, and Analysis Medical Statistics Certificate Program Writing in the Sciences Epidemiology and Clinical Research Graduate Certificate Program Programs that we teach in: Epidemiology and Clinical Research Graduate Certificate Program
Find us on: Kristin - LinkedIn & Twitter/X Regina - LinkedIn & ReginaNuzzo.com
(00:00) - - Introduction
(02:15) - - What is AFib?
(04:36) - - Frisky Goats and Satan's Bitter Invention
(10:44) - - How Caffeine Works
(14:43) - - The CRAVE Trial
(15:53) - - PICOT: Evaluating the Study Design
(23:24) - - CRAVE Results
(30:07) - - Catching the Coffee Cheaters
(37:01) - - The DECAF Trial
(41:30) - - Time-to-Event Outcomes
(43:21) - - Hazard Ratios: Balance Beams Over Shark Tanks
(47:06) - - DECAF Results: Team Coffee Wins
(50:38) - - Why Would Coffee Be Protective?
(53:57) - - Rating the Claim
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