Who should have bisphosphonates?
A Bisphosphonates are effective at preventing fractures in those at highest risk. A low bone mass is one of the strongest single risk factors. Osteopenia describes a bone density between -1 and -2.5 standard deviations (T-score) below sex-matched peak bone mass, but this alone is not associated with sufficient risk of fracture to justify a bisphosphonate.
Risk is greater with osteoporosis – a bone density of less than 2.5 standard deviations below peak bone mass age. Other factors such as previous fracture, maternal hip fracture, steroid use and certain diseases add to risk and treatment should be considered when they are present with osteoporosis.
The risk of falling must also be assessed. Age is the most important risk factor for fracture – a 50-year-old woman with T score -1.5 (osteopenia) has a 7.4 per cent 10-year probability of fracture – double in a 70-year-old woman.
The risk is significantly greater in a 70-year-old with osteoporosis (T-score below
-2.5). So treatment should be targeted at older people with risk factors and fracture probability confirmed by bone densitometry. It should be established that the person is willing and capable of taking a treatment long-term.
Returning to the case scenario, why did she have a bone density assessment? If she has risk factors for increased bone loss, a repeat assessment after five years may be advised.
A bone-healthy lifestyle should be recommended – adequate calcium and vitamin D, 30 minutes' brisk walking per day and avoiding smoking and excess alcohol.
NICE is currently looking at bisphosphonates as part of its appraisal of osteoporosis
Professor Tony Woolf is
Royal Cornwall Hospital, Truro