1 November 2011
There has been extensive media coverage recently of the findings of Luengo-Fernandez et al. (2011). Dementia is indeed a costly condition. But, from examining the Supplementary Data (http://www.j-alz.com/issues/27/luengo_supplement.pdf), is it possible that the cost has been over-estimated?
Firstly, was comorbidity and impairment not caused by dementia fully accounted for in estimating social care costs, given that dementia patients often have other conditions requiring care? If, say, a 90-year-old with osteoarthritis, heart failure, and impaired vision would have been able to cope at home with £300 worth of care per week, but because she also had dementia needed to be in a residential home at a cost of £800 per week, would the cost of dementia be calculated as £500 rather than the full £800?
Secondly, with regard to the cost of informal care, when ‘The time spent by relatives and friends providing unpaid care for dementia sufferers was obtained from country-specific studies evaluating the informal care patterns of dementia patients... The average hours of informal care given to each dementia patient was then multiplied by the number of people with dementia living in the community and annualized’, was sufficient account taken of the fact that such studies focus on those receiving care for dementia, while many (especially with mild dementia) do not receive informal or formal care and may not even be diagnosed?
Thirdly, with regard to outpatient visits, did the methodology used result in an excessive figure? In the team’s UK-based study ‘Dementia 2010: the economic burden of dementia and associated research funding in the United Kingdom’ (http://www.dementia2010.org/reports/Dementia2010Full.pdf), it was estimated that in 2006 there were 489,766 outpatient consultations for dementia, but this appears many times greater than the figure in the NHS Information Centre’s Hospital Episode Statistics for outpatient attendances in England (where the majority of the UK population lives) in 2006-7 (Primary diagnosis, 2006-07, Excel file).
London, UK; firstname.lastname@example.org
Response to Letter to the
Response to Letter to the Editor from Savitri Hensman
We thank Ms. Hensman for her comments and for her interest in our paper. We note her concerns that we might have overestimated the true costs of dementia in 15 countries of the European Union.
As made clear in our paper, due to the aggregate nature of the data used, the precision of a cost-of-illness study to estimate the burden of a disease across several countries depends on the quality and availability of comparable data across the countries of interest. It is also worth stressing that our study omitted relevant costs including: formal home care provided by social services or paid privately (e.g., home assistance, home help, meals on wheels, etc.) and pharmaceuticals typically consumed by dementia patients such as antipsychotics, anxiolytics, hypnotics, and antidepressants. These costs were not included as there was insufficient information in the majority of countries to make an informed estimate.
In our paper, we clearly highlight the limitations of the study, chief among them the fact that for a number of components, including primary and outpatient care visits, as well as hours of informal care, resource use was derived from published studies following cohorts of diagnosed dementia patients rather than from cases identified using population-based studies.
The numbers of institutionalized patients with dementia was estimated using country-specific data derived from a variety of sources, mainly published studies assessing the prevalence of dementia in those living in long-term care homes on the basis of a clinically oriented assessment interview. In our study, we made the assumption that all dementia patients living in nursing/residential accommodation were institutionalized because of their dementia. Of course, this may not be true for all dementia cases, some of whom will have developed dementia prior to institutionalization. However, as documented in the published literature, dementia is a very strong predictor of institutionalization. In fact, for dementia patients living at home, the main predictors of institutionalization appear to be severity of disease/impairment, age of carer, and carer’s state of health [1-3].
As correctly pointed out by Ms. Hensman, the hours of informal care were derived from studies using samples of diagnosed dementia patients (which excluded non-diagnosed cases). However, it is important to note that not all diagnosed patients have moderate or severe dementia. Furthermore, informal care is also provided to patients with mild dementia. For example, in the study used to estimate hours of informal care in the UK , the mean Global Deterioration Scale amongst patients receiving care in the community was 3.72 (i.e., mild cognitive impairment-early dementia).
Regarding the concerns about how the number of outpatient visits was estimated in the UK: The NHS Information Centre’s Hospital Episode Statistics (HES) states that “... primary diagnosis is not a mandated field in the outpatients dataset, therefore coverage within this field is poor” . In 2006-7 there were 51,939,835 outpatient visits in England as recorded by HES. Of these, no primary diagnosis was recorded in 50,666,371 (97.6%) outpatient visits, which were recorded as “Unknown and unspecified causes of morbidity”. For this reason, the number of outpatient consultations for dementia estimated in our study is higher than those recorded in HES.
In summary, despite the limitations that we fully acknowledge in our paper, we believe our study provides a good indication of the economic burden of dementia in 15 European countries.
Ramon Luengo-Fernandez, DPhil; Jose Leal, DPhil; Alastair M. Gray, PhD
Health Economics Research Centre, Department of Public Health, Old Road Campus, University of Oxford, Oxford, UK
 Hope T, Keene J, Gedling K, Fairburn CG, Jacoby R (1998) Predictors of institutionalization for people with dementia living at home with a carer. Int J Geriat Psychiatry 13, 682-690.
 Agüero-Torres H, von Strauss E, Viitanen M, Winblad B, Fratiglioni L (2001) Institutionalization in the elderly: The role of chronic diseases and dementia. Cross-sectional and longitudinal data from a population-based study. J Clin Epidemiol 54, 795-801.
 Hébert R, Dubois MF, Wolfson C, Chambers L, Cohen C (2011) Factors associated with long-term institutionalization of older people with dementia: data from the Canadian Study of Health and Aging. J Gerontol A Biol Sci Med Sci 56, M693-M699.
 Schneider J, Hallam A, Murray J, Foley B, Atkin L, Banerjee S, Islam MK, Mann A (2002) Formal and informal care for people with dementia: factors associated with service receipt. Aging Ment Health 6, 255-265.
 The NHS Information Centre. Hospital Episode Statistics for England. Outpatient statistics, 2006-07.http://www.hesonline.nhs.uk, Accessed 22 November 2011