Use of preventive medicines in the elderly
Friday 10 August 2007
Use of preventive medicines in the elderly needs rethinking
Dr Dee Mangin from the University of Otago, Christchurch argues in this week’s British Medical Journal (BMJ) that using preventive medicines in the elderly aimed at reducing the risk of a particular disease may be simply changing the cause of death rather than prolonging life.
The goal of drug treatment for prevention is to delay the onset of suffering caused by illness and disease and to prevent premature deaths. The difficult question as to what to do about prevention after people have exceeded an average lifespan has not been answered she says.
Dr Mangin says the use of statins, drugs for reducing cholesterol to prevent cardiovascular disease, is a good case in point.
The largest trial of statins in the elderly shows a decrease in illness and death due to heart disease. This study is used to support guidelines promoting use of these drugs for prevention in the elderly.
However, preventive use of statins in the trial showed no overall benefit in elderly people as illness and deaths from heart disease are replaced by cancer.The most likely reason for this effect in the elderly is substitution of cause of death. If we accept the inevitability of death this is logical - given that our bodies have a finite functional life, various systems wear out at a similar rate. We know if an older person has one chronic disease, they will often have several others. It therefore makes sense that prevention will have diminishing returns in older people.
Dr Mangin, in association with colleagues in the UK, argues in the BMJ that GPs are increasingly being encouraged to prescribe drugs for preventing heart disease by national guidelines for treatment, which are focussed on single diseases rather than a broader view.
“This alternative view of the data indicates a need to reconsider the way we think about drugs for prevention in the elderly,” says Dr Mangin. “All medicines carry potential harms, and risks are much greater for the elderly. When we give drugs as preventive treatments we need to be reasonably certain they will fulfill their promise.”
Dr Mangin and colleagues argue there needs to be a reassessment of preventive treatments for older people.
“We need a more sophisticated way of assessing the benefits and harms of preventive treatment in elderly people.”
“The best interests of the elderly, who’ve paid a lifetime of taxes, may well lie in investing public money in health care to relieve suffering rather than preventive drugs at the end of life. Cataract operations, joint replacements, and dementia care are just a few obvious examples,” she says.