If you’ve ever been to a hospital during off hours you know that is much quieter than during middle of a weekday. There are usually fewer visitors and fewer staff. If your heart stops (cardiac arrest) during these quieter hours it might take longer for someone to respond.

An article in the Journal of the American Medical Association finds that these quiet times may indeed translate into higher risk. The researchers examined nearly 60,000 in-hospital cardiac arrests. Those whose heart stopped during nighttime were less likely to survive compared to day or evening emergencies. Weekday survival was less likely than weekend. Interestingly, nighttime and weekend survival was the same.

It’s not clear if staffing delays are the only cause of survival difference. Nevertheless, those heart attacks which occurred in monitored in units such as the emergency room and ICU (intensive care unit) had a better chance of survival. These areas tend to have similar round-the-clock staffing, while regular floors tend to have fewer nurses and support staff during off-hours.

In summary, a cardiac arrest is best had during regular business hours.