Map of life expectancy at birth from Global Education Project.

Monday, November 27, 2006

Clearing the in-box: News you can Use

Sorry for the absence, but I warned you. Life is not always compatible with blogging, after all there was no blogging as our ancestors evolved on the African savannah. Anyhow, here are a few items I want to clear away before getting back to the regular rhythm.

1. The new edition of Health United States is out. I haven't had a chance to read it yet -- it's only 559 pages but I guess I'm a little bit lazy. Anyway do check it out if you're interested in how we're all doing. We'll be referring to it often in the months ahead I'm sure. The bottom line, in any event, is no surprise. From the Executive Summary:

In 2003, American men could expect to live 3 years longer, and women more than 1 year longer, than they did in 1990 (Table 27 and Figure 24). Mortality from heart disease, stroke, and cancer continued to decline in recent years (Table 29 and Figure 27). With longer life expectancy, however, comes increasing prevalence of chronic diseases and conditions that are associated with aging.

2. CDC has released the new recommended adult immunization schedule. There are a few important changes. The new Human Papilloma Virus vaccine is recommended for young women; adults should get a tetanus, diphtheria, pertusis booster; you should get a varicella (chickenpox) shot if you aren't immune; some adults should get a mumps booster; etc. I say vaccination is a good thing, and you should check with your doctor to make sure you're up to date on everything.

3. Jerry Avorn, in NEJM, in an article free to the common rabble, kicks the drug industry around the block. Bayer hid evidence, for a long time, that the drug aprotinin, given to prevent post-operative bleeding, caused kidney failure, heart attacks, and strokes. He recites other well-known atrocities: Merck hiding evidence of the dangerousness of Vioxx; and companies making public only the most favorable trials of Selective Serotonin Reuptake Inhibitors (which are still among the most widely prescribed drugs despite being utterly worthless in most cases, IMHO). He drives in the nail with a single blow here:

Many aspects of the aprotinin saga are familiar to observers of the drug-evaluation process: a product is approved because it is more effective than placebo, worries emerge about its safety, few or no adequately powered controlled trials are conducted to address these issues, and payers spend huge sums on the drug, despite the dearth of evidence that it is better than older, cheaper agents. The health care system has a hard time performing drug-safety analyses, in large part because it relies on the pharmaceutical industry to conduct most research on the risks and benefits of medications. It is naive to expect companies to voluntarily fund studies that could sink lucrative products, the FDA lacks the regulatory clout to require them, and despite the $220 billion we spend on drugs each year, we apparently can't find the resources to provide public support for these studies, even if the results could be of great clinical importance and save millions of dollars. Although a large randomized trial would have provided a valid means of comparing aprotinin with other treatments, no such study has been undertaken on the necessary scale.

4. No doubt you have heard or read about the new research on surgery for herniated disk reported in JAMA. The editors have given the public access to the main research report, but not the accompanying editorial by David Flum, which is actually more important. The news reports I have seen aren't much help to the public in interpreting all this.

As you know, lower back pain and sciatica are very common problems, which can be extremely painful and disabling. A hypothesis about the cause, or at least one cause, is that the symptoms result from a rupture and bulge of one of the cushioning disks between the vertebrae, which then impinges on a nerve. I say this is only a hypothesis because X-rays often show such a bulging disk in people with no symptoms, and people can also have similar symptoms without the lesion. Anyhow, spinal surgeons like to operate to remove the bulge, and many people report improvement afterwards.

The new study attempted to randomize people to surgery, or non-surgical treatment such as physical therapy and just waiting. The randomized trial didn't really work out, however, because many people assigned to surgery didn't get it, and vice versa. This creates difficulties for interpretation, because people who chose to get surgery or not to get it might be different to begin with. In a sunflower seed shell, the bottom lines are:

  1. People who got surgery and who did not get surgery both tended to get better over time;
  2. "Intention to treat analysis" didn't show any meaningful difference between people originally assigned to surgery and non-surgical treatment;
  3. People who actually got surgery reported more improvement in subjective symptoms early on. The differences narrowed over time but persisted. However, there was no difference between people who did and did not get surgery in the percentage who were working after two years.

This could mean that surgery works better, but it is also possible that since people who had more subjective distress were more likely to choose surgery, people who initially have more distress tend to improve more. Dr. Flum emphasizes a problem that many readers may find surprising: there is often a powerful placebo effect from surgery. For example, it used to be common to tie off the internal mammary artery of patients with heart disease, but a study in 1959 found that when patients were anaesthetized and had their chests cut, but with no ligation of the artery, they improved even more! In another study, sham knee surgery for people with osteo-arthritis worked as well as real surgery. Injecting embryonic nerve cells into the brains of people with Parkison's disease worked as well as injecting nothing. And so on and so forth.

Now you might say, so what if it's the placebo effect? It works. Maybe so but if we could just get people to believe as much in physical therapy and just waiting as they believe in surgery, those options might also work just as well. Right now, we really don't know. So in discussing their options with their doctors, people with sciatica might propose delaying surgery if they can stand it, to see if they can get better without it. They probably will. In fact, consider this, from a short item by Tracy Hampton in the same issue:

When a builder recently arrived at an emergency department, writhing in pain with a 12-inch nail lodged in his foot, nurses carefully removed his boot to find that the nail was harmlessly inserted between two toes. Seeing this, the man's pain suddenly vanished.
(I apologize on behalf of Dr. Hampton for the dangling participle.)

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