The final nail in the coffin . . .

of AIDS denialism. A multitude of Brits has completed a prospective cohort study of people living with HIV from 1996 through 2008. This is the most powerful, persuasive study design possible. It's Da Bomb of studies of HIV treatment. 1996 is basically the year when effect antiretroviral treatment became available. Here's the bottom line:

1) Life expectancy at age 20 of people living with HIV increased from 30 to 45.8 years over the period.

2) Life expectancy at age 20 was 37.9 for people who started therapy with CD4+ cell count less than 100; for people who started therapy with CD4+ count above 200, it was 53.4, getting up there pretty close to normal.

This "life expectancy" number is artificial, of course - I've explained it here before. But it's the best estimate of what a person age 20 can expect based on the experience we have with people of all ages with HIV since 1996. For those who don't know, CD4+ cells are a particular type of immune system cell, also called "helper T cells," that HIV preferentially infects and destroys. It's the loss of those cells that causes the immunodeficiency characteristic of AIDS.

So this is what we keep telling the AIDS deniers: if you have HIV, and you don't take the pills, you get sick and die. Even if you take the pills starting fairly late, after your T-cells are depleted, the numbers will come back but you aren't likely to live such a long healthy life, probably because you no longer have the variety of T-cells needed to confront the variety of pathogens you're likely to experience, and possibly because of other damage as well. But if you take the pills, take them regularly, and stick with it, you can look forward to a reasonable life span. Fact. Done.

That doesn't mean it's okay to get HIV. The pills have side effects, they're expensive, and you won't likely live as long or be as healthy as you would be without the infection. You'll do okay, but you really don't want it.

That said, and given that prevention is still the far better alternative, this does show that what I learned in school about the fairly small contribution of medical intervention to health and longevity is no longer true. Medicine has gotten better. It can pay real benefits. It's still true that it's even more important for people to have good diets, maintain healthy weight, not be assaulted by environmental contaminants or violence or poverty, not smoke or otherwise poison themselves, and so on. And it's also still true that too much medical intervention can be as bad or worse than too little.

But even if you're lucky enough to have all the good stuff and do all the right stuff, you're still gonna want a doctor.

And that's why we need universal access to high quality, evidence based medicine. And that's why we need universal, comprehensive, single payer national health care.