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Avoid Bone Density Testing for Osteoporosis

What is bone density scanning? Bone density scanning, or dual-emission X-ray absorptiometry (DXA or DEXA) uses low-dose X-ray energy to measure the bone-mineral density of bones. How is the result of a bone density test reported? The result of a bone density test is expressed as a “T-score,” which is how your bone density compares to a healthy 30-year-old of the same sex and ethnicity. How accurate is a T-score? T-score is very controversial in that it sets a cutoff that determines which women are classified as having osteoporosis (or the milder version, osteopenia). That cutoff is somewhat arbitrary and leads doctors to label those women with a low T-score as having a disease when, in most cases, the variations in their bone density are normal for their age. Is there scientific proof that bone density scanning is useful? Dr. Ken Bassett is a medical-school professor at the University of British Columbia and has spent much of his medical career assessing the benefits of drugs and technologies. He had a front-row seat when most of the osteoporosis controversy began. And it began with a screening test. In the mid-1990s Dr. Bassett was part of a team at the British Columbia Office of Health Technology Assessment (BCOHTA) in Vancouver, British Columbia. His team was tasked with gathering all the available evidence around bone-density testing and producing a report that would help advise the Ministry of Health about its appropriate use. Their report, “Bone Mineral Density Testing: Does the Evidence Support Its Selective Use in Well Women?” was launched in 1997. Dr. Bassett and his colleagues concluded (after their exhaustive comb through the literature) that the research evidence didn’t support “either whole population or selective bone-mineral density testing of well women at or near menopause as a means to predict future fractures.” In other words, there wasn’t any scientific proof that the bone-density testing did what it was promoted as doing: identifying women at high risk for bone fracture so that their doctors could provide them with the education, counseling, and possibly drug treatment they needed to prevent future fractures. If there is no scientific proof for bone density testing, then why it has become a routine part of medical testing? You would have thought that intelligent heads would have looked at the data compiled by Dr. Bassett and his colleagues and then scrapped the entire bone-density testing industry. But that didn’t happen. The enthusiasm for bone-density testing took off, driven by a lucrative new drug market ready to cash in on all those women with low T-scores. Sales of bisphosphonates, such as Fosamax, grew rapidly. Is bone health as simple as a test and a pill? The problem, according to Dr. Bassett, is that bone health is complex, and believing that a single measure of a bone’s density can accurately predict with any certainty what will happen many decades later is very wishful but misguided thinking. What does Dr. Bassett think about the wisdom of giving these drugs to women who are otherwise healthy but have been screened by a machine and told they have “low” bone density? He says, “If you’re giving them to healthy people, the burden of proof is so strongly on the part of the people promoting these products... they have to be proven to at least do more good than harm before you can give them to a healthy population.” And twenty years later, as the evidence of the harms of osteoporosis drugs continues to accumulate, we’re still waiting for the burden of proof on bone-density testing. So how did this entire bone density testing come about? A number of PR firms working in the field of osteoporosis in the mid-1990s were key in reconfiguring osteoporosis from a rare disease that was believed only to strike old ladies to something anyone of any age could get. And in the shadows, funding these activities were pharmaceutical companies like Merck, banking on a big market for its new drug Fosamax. The strategy was simple:

  1. Convince women at younger and younger ages that they needed to be screened for this bone-weakening disease, so they were urged through ads and so on to consult their doctors for a bone-density test.

  2. The bone-density testing machines needed to be in physicians’ offices, private clinics, and hospitals, so the manufacturers bought and distributed the machines.

  3. The tests needed to be paid for, so the PR firms needed to lobby governments to cover the bone-density test.

What most people don’t know is that if you define a disease broadly enough, you can capture a large part of the “healthy” population. Most also won’t know that drug company executives found themselves at the table at a meeting of the World Health Organization in 1995, helping to create the very definition of osteoporosis. The definition they created was so broad—based on the arbitrary value of the T-score—that it meant that about 50 percent of post-menopausal women in the United States (or about 44 million women) had it. And the message that flowed from the popular press strongly suggested that even the healthiest people should be worried about falling and breaking a hip due to the weakening of their bones.

The main concern with osteoporosis is hip fractures . What is the best way to prevent hip fractures?

According to Dr. Ken Bassett, Dr. Nortin Hadler, and Dr. Gilbert Welch guard against falls. That is the best way to avoid hip fractures.

I conclude with this passage from Overdiagnosed: Making People Sick in the Pursuit of Health by Dr. Gilbert Welch. Here he recounts his conversation with a drug company rep while traveling: "At thirty thousand feet, this drug rep was telling me about a new drug called Forteo. It’s a drug for osteoporosis, a condition that, he wanted to be sure I understood, had major public health implications. Millions of women have it (he might even have used the words suffer from it). Forteo is a synthesized portion of the naturally occurring parathyroid hormone, or PTH for short. PTH stimulates bone formation. So does Forteo. I was interested to learn all this. But I wanted to know if the drug really helped anybody. He told me about a randomized trial comparing the new drug to placebo in over sixteen hundred women and the significant benefits found in terms of bone density, bone volume, and bone mass. He talked about how everyone in the study who had taken Forteo had had X-rays and bone-density scans that proved the bones were now more dense. But I still wanted to know whether the drug had helped anybody. The reason to treat osteoporosis isn’t to make your bones look better on a scan (this doesn’t necessarily make you feel or look any better). The only reason to treat osteoporosis is to reduce the number of bone fractures. He acknowledged that that was a good point. But he was ready for it. He communicated the data showing that the drug reduced the number of spinal compression fractures. How serious are compression fractures of the spine? It depends. A compression fracture is a narrowing of the height of an individual vertebra in the back. The vertebrae are like a stack of hollow bricks supporting the weight of the body. A compression fracture occurs when one of those bricks is compressed by that weight. The fractures sometimes hurt a great deal, but the majority are silent and don’t hurt at all. Usually, the only way a person even knows she has one is if it is discovered by an X-ray. So does Forteo help reduce the number of fractures that actually bother people? Or does it simply reduce the ones people never would have known about if they hadn’t been seen on X-rays? In fact, the drug did appear to reduce the amount of “new or worsening back pain” from 23 percent to 17 percent over about two years. But what I really wanted to know about was not compression fractures but hip fractures. There is no ambiguity with these fractures. They are never silent—they always matter. People with hip fractures can’t walk. Virtually all require hospitalization. They need to have pins put in their hips or have their hips replaced entirely. And there’s little doubt that having a hip fracture is a major risk factor for death. The drug rep said the study wasn’t able to look at that. “But,” he said, “there isn’t a person on the planet who doesn’t believe that this drug substantially reduces the risk of hip fracture.” I begged to differ. I told him he was sitting next to one. This got a good laugh. And his demeanor changed markedly. It turned out he was a pretty nice guy. He was interested to learn that there was a medical school filled with other doctors who might ask him similar questions. And then he let his guard down. “You know, if we really wanted to prevent hip fractures we’d take a different approach. Patients get hip fractures because they fall. Preventing falls in the elderly would go a longer way towards reducing hip fractures than all the medications in the world.” I told you these guys were smart. But the bottom line is that drug reps are salespeople—men and women whose job is to help pharmaceutical companies make money, and pharmaceutical companies have a strong financial interest in pushing early treatment for all kinds of diseases. Incidentally, the Forteo study was stopped early. It was supposed to be a three-year study, but it was stopped short of two years because rats in a long-term study of it developed bone cancer. While the FDA approved the drug, it required the company to conduct a ten-year trial looking for increased osteosarcoma in users of the drug (in the meantime, the FDA forbade the company to distribute free samples to physicians or to conduct direct-to-consumer advertising). Unfortunately, no results of the post-marketing surveillance were available nearly ten years later. As of this writing, Forteo is still on the market.” And if you are concerned about osteopenia, take a look at this article Stay informed. Stay well.


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