Working Hours

We doctors have a long history of working long hours. We're trained to do so. Shortly after graduating from medical school, accomplishing the task of internship requires that we define forty-eight hours - not twenty-four - in a day.

With time, we unknowingly enter an addiction loop of long-hour working, which means staying on task until it's done instead of breaking the whole thing into manageable chunks. That explains why I won't be home until eight on most of my working days. I started to worry when I read an meta-analysis published in the medical journal Lancet last week.

The downside of working 55 or more hours per week, they report, is that there is an increased risk for stroke. Bile and dread inched up my throat. I thought to myself: Scary.

Well, that's what the researchers found after pooling data from nearly 530,000 adults who were free of stroke at baseline. During roughly 7–8 years' follow-up, the longer working hours one is engaged in, the higher the stroke risk. That is, the dose-response relationship between working hours and the risk of stroke speaks volumes to the threat - and for good reasons. For one thing, our brain weighs three pounds (only 2% of an adult's body weight) but consumes 20% of all the energy the body uses. The wear and tear of long working hours could have explained the energy crash or sudden exhaustion of the brain. For another, those who overwork tend to ignore their health. That doesn't mean the increase in stroke risk simply comes from smoking and drinking after long working hours; those risks have been factored in when the researchers calculated the odds.

Ahem. Sure enough, I'm not calling for a cut in doctors' working hours based on an observational study. All those conclusions drawn without a more experimental way - such as random allocation of individuals working long hours to reduced working hours - should be taken with at least that much of a grain of salt. To that matter, what am I to think? I am not sure what to say, but I didn't go back to my hospital after giving a lecture in another hospital yesterday. I went to meet my daughter in the playground instead of heading back to work.

Playground. Yes, it's unusual.

Even if the Lancet paper isn't rocket science, it makes me less guilty of leaving work early this Friday. Hooray.