Adherence to medication in patients with dementia: predictors and strategies for improvement.

Measures to facilitate patient medication adherence should be considered an integral part of the comprehensive care of older patients with multiple diseases. However, impairment of cognitive functions and dementia, in particular, may substantially compromise adherence behaviour. Therefore, a literature review was performed to identify factors associated with adherence to medication in patients with cognitive impairment or dementia, and to discuss strategies for improvement of non-adherence. Evidence-based information on how to deal with adherence to medication in patients with dementia is scarce because of a lack of specific studies. However, there is increasing knowledge about factors influencing medication adherence behaviour in older age, and emerging insight into the relationships between adherence behaviour and cognitive capacity, memory and executive function, in particular. Nevertheless, understanding elderly persons' strategies for maintaining regular use of even complex drug regimens is still limited. Progress of research in this field is needed. It is notable that measures to improve adherence consist of combinations of educational interventions and cognitive support but assessment of study participants' cognitive function is rare. In clinical practice, awareness of non-adherence as a result of cognitive impairment is relatively low. The most important step is early detection of cognitive impairment when this is impacting negatively on medication management. A practical geriatric screening test is recommended to identify memory problems and further functional impairments associated with cognitive impairment. Performance-based assessments might be useful for screening medication management capacity, in addition to a careful drug history, inspection of all medicines used (including over-the-counter drugs) and proxy information. However, no feasible screening methods have as yet found their way into clinical practice. Patients with impaired executive function, lack of awareness of illness and personality traits such as independency and high self-confidence may be at particular risk of non-adherence. The question is when to switch patient medication self-management to another person's responsibility if cognitive decline progresses. Further research is needed on measures to differentiate cognitive function and the relationships between memory concerns, memory strategy use and medication management. Also, studies evaluating the influence of personal support, health status and depression on the memory strategies used are needed. It is important to assess patients' attitudes toward medication and their relationship with proxies. Strategies for facilitating medication adherence in patients with dementia include prescribing as few medicines as possible, tailoring dose regimens to personal habits, and coordinating all drug dosing schedules as much as possible. When providing medication organizers, it is important to observe the patient's ability to use devices appropriately. In addition, automated computer-based reminding aids, online medication monitoring and telemonitoring may be helpful for patients with mild dementia. The decision as to when assistance with medication self-management is needed has to be made taking into account patient independency and safety aspects. This holds true for medicines with a narrow therapeutic range, in particular. Interactions among the individual patient's cognitive status, mood, level of self-efficacy and particular living situation must also be taken into consideration when searching for the optimal medication adherence strategy. No evidence-based recommendations can be given as yet. However, comprehensive assessment of the individual patient and careful consideration of all potential drug-related problems will probably help facilitate adherence and prevent compromised health outcomes in patients with dementia.