Daylight Saving Time: Does springing forward cause heart attacks?

About this episode

This episode explores the complex relationship between daylight saving time and heart attack rates, examining various studies and statistical concepts.

Every year we spring forward and lose an hour of sleep. But do we also lose a few heart cells? Some headlines claim that heart attacks spike by 24% after daylight saving time begins. In this episode we trace that number back to the research behind it—and what we find is more complicated than the headlines suggest. We examine a famous New England Journal of Medicine letter, a large international meta-analysis, and a massive modern U.S. registry study. Along the way we talk about incidence ratios, relative versus absolute risk, negative controls, and a haunting concept called harvesting. Plus: why bar charts are not for numerical data, why journalists love dramatic numbers, and how a bug collector helped invent daylight saving time. Statistical topics Incidence ratios / incidence rates Meta-analysis Negative controls Relative risk vs absolute risk Statistical vs practical significance Statistical Sleuthing Methodological morals “A bump in time isn’t always a bump in total.” “If you already know the story you want to tell, you can always find a number to tell it.” References Bourke, India. “An obsessed insect hunter: The creepy-crawly origins of daylight saving.” BBC Future , March…

People in this episode

Hosts: Regina Nuzzo, Kristin Sainani

Topics covered

• daylight saving time
• heart attacks
• statistical analysis
• risk assessment
• meta-analysis
• health effects

Keywords

• daylight saving time
• heart attacks
• incidence ratios
• relative risk
• meta-analysis
• negative controls
• statistical significance

Mentioned in this episode

Organizations: New England Journal of Medicine, BBC Future

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