MPH Master pieces

Fish oil

Shaper noted an absence of coronary heart disease in Kenyans. Burkitt pondered the rarityof bowel cancer among Nigerians. And Bang wondered why there wasn't much heart disease among Eskimo in Greenland, who live on a diet of meat and fat. Thus started three great stories in dietary epidemiology: cholesterol, fibre and fish oil.

Here is the latest review of the fish story. Many points of interest but don't try to read it all in one sitting or your brain will explode. There is a clear explanation of exactly what an omega-three oil is; a good review of trials of omega-3 oils in both primary and secondary prevention; and a new use of the Number Needed to Treat, or perhaps in this case the Number Needed to Catch: how many fish do you have to eat to prevent one heart attack? (Answer: pretty much all the fish in an average-sized ocean.)

The review also points out the need for exact detail in dietary trials - not just 'fish oil supplements' but what dose? And also detail on the subjects - what do they normally eat? In Japan everyone eats a lot of fish anyway, so offering yet more fish oil as a pill isn't likely to make much difference.

 

Health systems and blood pressure control

One doctor, one patient. That's how medicine works - right?

Nope. You need a system. The one doctor and the one patient need to be embedded in a system that works to their benefit. Here is a success story, and this excellent commentary explains how the success was achieved. Why can't the NHS do it? Too big, too diffuse, chasing after too many things. But I guess underlying it all is the determination to succeed.

I particularly liked this element:

"Reports were generated for each center every 1 to 3 months, and a central KPNC team identified best practices from high-performing centers and disseminated those reports to all other centers"

Planned behaviour

Kurt Lewin is famous for two things: Force Field Theory and his dictum: 'There is nothing so practical as a good theory'.

There are many theories about why people behave they way they do - smoke, drink, overeat, get screened or vaccinated, and so on. Ajzen's theory of planned behaviour offers us a way in. So this article is interesting, It has one huge flaw (of which more later) but it's a good worked example of theory >> action.

The flaw is the whole notion that screening for chlamydia infection is worthwhile - it probably isn't.

Malaria control - Alabama

We forget that the American South used to be malarious. Here is a beautiful article produced by a historian and a statistician. The historian gives us a compelling narrative and the statistician proves it with numbers.

The authors point out that malaria in, say, West Africa today is less tractable than in the southern USA 80 years ago: even so, this history matters.

Smoking control and hospitals

We don't think of hospitals as places for health promotion work, but a comprehensive strategy uses all avenues. So here is a trial of the hospital as a place to get smokers to quit.

It's difficult to work out whether this is an expensive thing to do or not. The smokers seemed to get about 30 minutes of counselling each (say £50), plus some nicotine replacement therapy (another £50??) but there must also be programme costs - for example you have to approach every patient, and in this trial about 30% declined consent. If I may venture a bold generalisation, almost anything that gets a smoker to quit will work out cost-effective at the NICE threshold of £30 000 per QALY.