Osteoporosis has many controversies. An informal global alliance of drug companies and sponsored advocacy groups portray and promote osteoporosis as a silent but deadly epidemic bringing misery to tens of millions of postmenopausal women. For other doctors and groups less entwined in the drug industry that promotion represents a classic case of disease mongering – a risk factor has been transformed into a medical disease in order to sell tests and drugs to relatively healthy women. What is the truth? The marketing volume of medication for osteoporosis is set to expand greatly as the push begins to treat even women with pre-osteoporosis – the women who are apparently at risk of being at risk – with medication. This condition is known as osteopaenia and affects more than half of all white postmenopausal women in the U.S. (and I am less and less convinced that ANY demographic research done in the USA can be translated to other countries, although their data is used to market drugs).
In 1994 a small group associated with the World Health Organization defined “normal” bone mineral density as that of young adult women, instantly (and without real evidence) categorizing many older women as having abnormal bones. The working group proposed that osteoporosis should be diagnosed when bone mineral density is -2.5 standard deviations below the mean value for healthy young adult women, and osteopaenia be diagnosed when bone density was -1-2.5 standard deviations below the mean for young women.
But we know that fractures are a rapidly growing problem. Hip fractures alone cost $20 billion US/year. Any intervention that may reduce the risk of fracture, at either the individual or population level, therefore warrants critical appraisal.
The mainstay of current strategies to prevent fractures is to screen for osteoporosis by bone densitometry and treat people with low bone density with anti-resorptive or other bone-specific drugs. BUT fractures occur much more commomly because of falls and not because of low bone density.
Despite this fact few doctors will have assessed the risk of falling among their elderly patients. A change of approach is needed.
Bone densitometry is not accurate, and can either underestimate or overestimate bone mineral density by 20-50%. A T- score of -1.5 might in fact be between -3 and 0 (i.e. a range of clear osteoporosis to normal). Thus, as expected, osteoporosis is a poor predictor of fracture in individuals. In addition: if different scanners are used on the same patients, the proportion of patients with osteoporosis varies from 6% up to 15%. Over 80% of low trauma fractures occur in people with who do not have osteoporosis (T score -2.5)
Because of this the WHO is devising a new model for calculating fracture risk.
This model combines age specifically with six clinical risk factors
steroid usage (e.g. for asthma, auto-immune diseases)
family history of fracture
alcohol excess and
If patients with a T- score -2.5 are treated, it will cost R230,000 to prevent one fracture, and 70% of fractures will still occur in the population. That is for vertebral fractures.
The situation for hip fractures is even more complex. Less evidence exists for medical treatment to prevent hip fractures. 577 patients must be treated at a cost of R1.8 million for one fracture to be prevented.
If it is not osteoporosis that is the main player but falls – what can be done to prevent falls? Some individual trials even report a reduction of 50% in falls. Randomized trials used either a single intervention strategy (such as exercise) or multi-factorial preventative programs that included simultaneous assessment and reduction of predisposing and situational factors:
Most important is strength and balance training,
followed by reduction in number and doses of psychotropic drugs
dietary supplementation with vit D and calcium,
and in high risk patients: assessment and modification of home hazards for falling. These include bad eyesight (cataract surgery can do a lot to improve this); cardiac pacemakers where indicated; and the use of gait stabilization and anti-slip devices indoors and outdoors under slippery conditions.
We tend to treat only what we can measure. Simple tests are:
To assess patients who have difficulty in performing a simple “sit to stand test”, or who take more than 13 seconds to get up from a sitting position. (Muscle strengthening exercises are indicated).
To perform a one leg balance test: if a patient cannot balance on one leg for 5 seconds, the chances of falling are increased (muscle strengthening and exercises to improve balance will make a big difference).
If it might be possible to select high risk patients and treat and train them, massive savings can be accomplished, over and above the preservation of quality of life of elderly patients. (Rope skipping was an easy reflex skill when we were young, but how many will still be able to do it? And how about walking on a narrow ledge?)
Quote: Everything is always more difficult than initially anticipated. (Murphy’s law)