Statins should not be given routinely to elderly people because the risks of side effects outweigh the benefits, US researchers have concluded, casting further doubt on NICE’s decision to lower the CV risk thresholds.
The team simulated the impact of blanket prescribing of statins to all adults aged 75 years and older and found that even relatively small potential increases in known statin-related side effects, such as cognitive impairment and muscle weakness, would mean it is no longer cost-effective for cardiovascular disease prevention in this age group.
GP leaders said the findings reinforced their concerns about the recently updated UK guidelines on cardiovascular prevention from NICE, which recommend statins for the vast majority of elderly people, and the way GPs’ performance on cardiovascular prevention is measured.
But NICE said that it was ‘impossible to draw conclusions’ from the study, because it analysed lower doses of statins than recommended by NICE, which meant the benefits were not as marked.
The researchers’ study found that prescribing statins to everyone aged 75 to 93 without existing heart disease would create some eight million additional statin users, and prevent 105,000 new MIs and 68,000 deaths from CHD – at a cost of US $25,200 (£16,000) per disability-adjusted life-year (DALY) gained.
However, they calculated that these benefits would be offset by even ‘modest’ increased risks of cognitive impairments or functional limitations, which are known side effects of statins.
They found that a reduction of just 0.003 DALYs due to statin-related cognitive impairment and declines in physical function would offset these benefits, resulting in net harm.
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Study author Professor Kirsten Bibbins-Domingo, professor of medicine, epidemiology and biostatistics at the University of California at San Francisco, said: ‘Prior studies have favoured statin use because of the clear benefits to the heart and because serious side effects are rare. Unfortunately, we don’t have enough studies in older adults, and as a result don’t know enough about how common or how severe the side effects are.
‘Our study showed that in older adults, even small increases in functional limitations and mild cognitive impairments from statin use could result in net harm.’
Professor Bibbins-Domingo and colleagues looked at giving statins to all people aged 75 and over because this age group are automatically classed as high-risk under recently updated US guidelines, which recommend statins at a 10-year risk of 7.5% or above.
NICE also recently updated guidelines for lipid modification, halving the estimated risk level at which people should be considered for a statin, to a 10-year cardiovascular disease risk of 10% for anyone aged 40 to 84 years, while anyone aged 85 and over is to be considered at high risk and eligible for statin therapy.
The change in the NICE risk threshold caused outrage among GP leaders who warned it would lead to overtreatment – particularly of the elderly – and to health resources being diverted from sick people to the ‘worried well’.
This concern has been raised further since NICE announced plans to introduce QOF indicators rewarding GPs for prescribing statins at the 10% threshold in patients with hypertension and diabetes.
Dr Andrew Green, chair of the GPC clinical and prescribing subcommittee, said the findings reinforced GPs’ concerns and showed GPs should not be rewarded through QOF for crude statin prescribing rates.
Dr Green said: ‘The two major areas of concern that the GPC has with the NICE statin guidance are the issues of prescribing for older patients, and for those at lower individual risk.’
He added that ‘care needed to be taken’ with the paper, as it looks at a lower threshold than NICE, but said ‘the principle holds true that the lower your individual risk, the more likely you are to be harmed rather than helped by intervention’.
Professor Mark Baker, director of the Centre for Clinical Practice at NICE said it was ‘impossible to draw meaningful conclusions about the possible impacts of the study on the risks versus benefits of statins as recommended in our guideline’, as the statin doses and therefore cholesterol reductions – and therefore cardiovascular benefits – assumed in the study were lower than recommended by NICE.
Professor Baker added: ‘It should also be noted that the authors of the study call for additional research to quantify both the potential benefits and harms of statin use in older adults – something we would endorse as being a potentially important addition to the already substantial body of evidence about these drugs. This body of evidence overwhelmingly supports the use of statins in reducing the risk of CVD, even in people at low risk and irrespective of their age. The effectiveness of these medicines is now well proven, as is their safety, and their cost has fallen.’
Ann Intern Med 2015; available online 21 April
