20th March 2009
Among the elderly, the greatest risk of fracture comes from falls, not osteoporosis. Bone mineral density measurement may be imprecise and it should not be used alone to estimate fracture risk or guide treatment decisions. All older people with recurrent falls or assessed as being at increased risk of falling should be considered for an individualised multifactorial intervention to reduce their risk. However, absolute reductions in the number of fallers may be smaller than previously thought.
Action: Healthcare professionals should follow NICE Clinical Guideline 21 on the assessment and prevention of falls in older people. In addition, NICE has recently published two technology appraisals on the use of drugs for the primary and secondary prevention of osteoporotic fragility fractures in postmenopausal women with osteoporosis. A combination of T-score, age and number of independent clinical risk factors is specified within the appraisals for each alternative treatment option. These should be considered when assessing a woman’s suitability for an alternative treatment option.
NICE is developing a clinical guideline on ‘Osteoporosis: assessment of fracture risk and the prevention of osteoporotic fractures in individuals at high risk’. The development of this is currently being reviewed following the publication of the technology appraisals.
One article argues that a change of approach is needed in managing osteoporosis, and suggests that efforts should be put into preventing falls rather than treating low bone mineral density (BMD) with medication. The authors point out that falling, not osteoporosis, is the strongest single risk factor for fractures in elderly people and that BMD is a poor predictor of an individual’s fracture risk. In addition, the authors state that measurement of BMD is unreliable and can over- or underestimate BMD by 20–50%. This means that, for example, a patient with a T-score of –1.5 may have a true value any where between –3.0 and 0, ranging from clear osteoporosis to the BMD of an average young woman.
Evidence shows that at least 15% of falls in older people can be prevented, with individual trials reporting relative reductions of up to 50%. Strength and balance training, reduction in the number and doses of psychotropic drugs, calcium and vitamin D supplementation, and assessment and modification of home hazards in high-risk populations, have all been shown to reduce the risk of falls. But the absolute rate of fracture is low and this may be the reason why the evidence that preventing falls among older adults also prevents fractures is less clear. Similarly, while bisphosphonates reduce the relative risk of fracture, there is comparatively little evidence that they prevent hip fractures in the general elderly population rather than being targeted at those at high risk of fracture. Also, administration requirements are complicated, and they can cause adverse effects making adherence with bisphosphonate regimens notoriously poor – around 50%. The authors conclude that general practitioners should shift the focus in fracture prevention by systematically assessing patients’ risk of falling and providing appropriate interventions to reduce the risk.
So, as discussed in an accompanying editorial, the problem is how best to prevent falls? A systematic review and meta-analysis of 19 trials has evaluated the efficacy of multifactorial assessment and intervention programmes to prevent falls and injuries among older adults recruited to trials in primary, community or emergency care settings. It found little evidence to support the effectiveness of multifactorial interventions to prevent falls and injuries. The authors conclude that interventions that actively provide treatments aimed at reducing risk factors may be more effective than those that only provide knowledge or referral. However, absolute reductions in the number of fallers may be smaller than previously thought.
Although drug treatment may be considered to be indicated in women with osteoporosis, the evidence is less clear in those with osteopenia. Another article examines data from four post-hoc analyses of trials used to support the treatment of women with slightly lowered BMD but at a low absolute risk of fracture. The authors argue that the benefits of such treatments (raloxifene, alendronate, risedronate, strontium ranelate▼) have been exaggerated and the harms have been played down. They state “when absolute baseline risk of fracture is low, as it is for women without existing fractures or other major risk factors, the absolute benefits of any treatment will similarly be low, and the numbers needed to treat will be high. Impressive sounding reductions in relative risk can mask much smaller reductions in absolute risk.”