New York City's death rate from coronary heart disease is well above the national average, and has been for decades. But the stroke death rate there is low, which is odd given that stroke and CHD share the same risk factors. Also, health surveys show that New York is better than the national average for obesity, hypertension and smoking.
So what's going on?
Well, this is a reminder to think about where mortality statistics originate. Stats by cause of death start with a doctor writing a death certificate. So it's an opinion. And different people have different opinions. It seems from this research (a couple of years ago but I've only just come across it) that New York doctors overdiagnose CHD.
I've seen that before in small area stats where the habits of a single doctor can influence apparent mortality rates, but never before for so long for such a big area.