Dementia (including Alzheimer's disease) is a global healthcare concern; there are approximately 24 million people worldwide with dementia, and this is likely to increase to 81 million by 2040. Dementia is a slowly progressing condition, and persons affected may experience a gradual decline over eight to ten years. Medications that are appropriately prescribed when someone has mild dementia may no longer be appropriate as dementia progresses to severe. Statins are prescribed to lower cholesterol levels in the blood; in most cases, they help prevent myocardial infarctions (heart attacks) or strokes, but the benefits are only seen after using them for a period of months or years. They have well known side-effects, such as muscle pain, and it is not known if the benefits of these medications outweigh the risks in persons with advanced dementia.
Study characteristics
We searched several medical databases on 11 February 2016 to look for clinical trials that compared continuing a statin to withdrawing a statin, in persons with dementia.
Key findings
We found no studies that were suitable for our review. This highlights the need for further high quality research into this area.
We found no evidence to enable us to make an informed decision about statin withdrawal in dementia. Randomised controlled studies need to be conducted to assess cognitive and other effects of statins in participants with dementia, especially when the disease is advanced.
There are approximately 24 million people worldwide with dementia; this is likely to increase to 81 million by 2040. Dementia is a progressive condition, and usually leads to death eight to ten years after first symptoms. End-of-life care should emphasise treatments that optimise quality of life and physicians should minimise unnecessary or non-beneficial interventions. Statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors; they have become the cornerstone of pharmacotherapy for the management of hypercholesterolaemia but their ability to provide benefit is unclear in the last weeks or months of life. Withdrawal of statins may improve quality of life in people with advanced dementia, as they will not be subjected to unnecessary polypharmacy or side effects. However, they may help to prevent further vascular events in people of advanced age who are at high risk of such events.
To evaluate the effects of withdrawal or continuation of statins in people with dementia on: cognitive outcomes, adverse events, behavioural and functional outcomes, mortality, quality of life, vascular morbidity, and healthcare costs.
We searched ALOIS (medicine.ox.ac.uk/alois/), the Cochrane Dementia and Cognitive Improvement Group Specialised Register on 11 February 2016. We also ran additional searches in MEDLINE, EMBASE, PsycINFO, CINAHL, Clinical.Trials.gov and the WHO Portal/ICTRP on 11 February 2016, to ensure that the searches were as comprehensive and as up-to-date as possible.
We included all randomised, controlled clinical trials with either a placebo or 'no treatment' control group. We applied no language restrictions.
Two review authors independently assessed whether potentially relevant studies met the inclusion criteria, using standard methodological procedures expected by Cochrane. We found no studies suitable for inclusion therefore analysed no data.
The search strategy identified 28 unique references, all of which were excluded.