Co morbidity and polypharmacy in dementia – time for action?
Reflections on a recently published article in Age and Ageing by Clague et al. (2016)
Populations are ageing across the world, leading to growing numbers of people surviving to develop dementia, many of whom will have complex care needs.
“Today, 47 million people live with dementia worldwide, more than the population of Spain. This number is projected to increase to more than 131 million by 2050, as populations age. Dementia also has a huge economic impact. The total estimated worldwide cost of dementia is US$818 billion, and it will become a trillion dollar disease by 2018.” World Alzheimer Report 2016, Alzheimer’s Disease International
Previous studies have had mixed findings as to whether people with dementia have more health conditions or use more medications than others of the same age, although such studies have often been small or have been based on highly selected samples. Our study analysed numbers of co-morbid health conditions and medications in a sample drawn from 314 Scottish general practices of 291,169 people over 65, of whom 10,258 (3.5 per cent) had a dementia diagnosis recorded, making this one of the largest population analyses carried out to date.
What did we find?
People with dementia had higher numbers of co-morbid conditions. After adjustment for age and sex, people with dementia were more likely to have five or more physical conditions (not including dementia) and to be on five or more repeat prescriptions. Parkinson’s disease, epilepsy and constipation had the highest relative prevalence among people with dementia, compared to controls.
Our results rely on the recording of “diagnosed” dementia and may underestimate comorbidity, for example among residents in long term care with “known” but not formally diagnosed dementia.
People with dementia were also prescribed larger numbers of medications than age and sex matched controls. Over half of those with dementia were on five or more repeat prescriptions with 43.2 per cent on five to nine repeat prescriptions compared to 32.4 per cent of controls and 14 per cent on ten or more compared to 8.4 per cent of controls.
Others have found that increased comorbidity and polypharmacy are both associated with increased cognitive and functional decline, in addition to possible associations between higher levels of medication use and increased mortality. A study of US claims data indicated that, when illness burden is controlled for, the care costs of patients with dementia may be up to 34 per cent higher than those of aged matched controls, where medication is the main reason for cost difference. Previous work using our Scottish dataset has shown that people with dementia are seventeen times more likely to be prescribed an antipsychotic and twice as likely to be prescribed an antidepressant or a hypnotic/anxiolytic than older people without dementia.
These findings highlight the importance of effective multidisciplinary integration between specialist and non-specialist services. People with dementia have many other care needs, making it important that their other care needs are accounted for by specialist dementia services, and that their dementia is accounted for by other services. Supporting primary care is a key role for specialist services, both by providing specialist care on referral, and to provide advice and education.
The findings support growing international consensus about the care needs of people with dementia.
Healthcare for people with dementia needs to be:
Continuous: treatment options, care plans and needs for support must be monitored and reviewed as the condition evolves and progresses.
Holistic: treating the whole person, not single conditions, organs or systems and mindful of that person’s unique context, values and preferences.
Integrated: across providers, levels of care, and health and social care systems”
World Alzheimer Report 2016, Alzheimer’s Disease International
Polypharmacy in particular, needs careful review, since people with dementia will often (but not always) have lower expected benefit from preventive medications and are usually at higher risk of harm, making it important to minimise over-medication in this frail population.
Perth Area Psychological Therapies Service, NHS Tayside,
School of Medicine, Dundee
The fully referenced paper was published in Age and Ageing