“Landeiro and colleagues computed the economic burden of four diseases (cancer, coronary heart disease [CHD], dementia, and stroke) in England using consistent methodology and a broad definition of disease burden. This analysis is an important advance that will allow policy makers, researchers, and other stakeholders to assess the absolute and relative burden of these diseases in a meaningful way. The Global Burden of Disease also uses a consistent methodology for estimating the burden of many diseases across countries. However, its methodology focuses only on mortality and morbidity, which are evaluated comprehensively, but does not account for many other costs included in the work by Landeiro and colleagues, most notably the costs of formal and informal care.
Landeiro and colleagues’ work illustrates the difficulties with obtaining suitable estimates and the effect of different reasonable methodological choices, which is most apparent when evaluating the cost of informal care. In this work, 1 h of informal care was valued at £7·85, which is the average wage of a (non-senior) home care worker, but 1 h of formal care was valued at £27·00, which is the average cost of hiring a caregiver (including overhead costs). Formal care has been valued at the cost that is actually paid (and the amount that would have been saved in the absence of the disease), whereas informal care has been valued as the amount that an informal caregiver would earn for the same task if they were a formal caregiver instead, making this choice of cost valuation a reasonable methodological choice. However, if a household needed to hire a formal caregiver instead of providing the care themselves, they would need to pay £27·00 per hour for caregiving. Therefore, one could also argue that this is the best measure of the cost of informal care. Using this valuation, the total cost of care would be £21·1 billion for cancer (vs the authors’ estimate of £18·9 billion), £14·5 billion for coronary heart disease (vs £12·7 billion), £20·6 billion for dementia (vs £11·7 billion), and £10·1 billion for stroke (vs £8·6 billion). For cancer, CHD, and stroke, the differences in the total cost are non-negligible but modest, but for dementia, using the higher cost valuation of informal care almost doubles the cost, and this choice greatly affects the relative costs of the diseases. Landeiro and colleagues valued productivity losses in terms of average wage, which is approximately £16 per h (£129 per 8 h). Some authors prefer this method for valuing informal care, making it another reasonable methodology. This approach results in total costs falling in between the cost reported in the paper and the estimates that value informal care the same as formal care.
As Landeiro and colleagues acknowledge, hours of supervision are likely to be severely undercounted, as these hours were not elicited in the English Longitudinal Study of Ageing survey. For dementia, the hours of supervision have been estimated to be 29% of the total hours of informal care in the European Region; thus, including this proportion of hours of supervision would potentially increase the burden of informal care for dementia (and possibly stroke) by 41%, but likely much less for cancer and CHD.
Alternative choices regarding productivity losses can substantially affect the absolute and relative cost estimates. The study by Landeiro and colleagues considered only the first 90 days of missed work as productivity loss due to morbidity, while all future productivity losses were attributed to mortality. If productivity losses due to morbidity encompass all future losses beyond the first 90 days of missed work, the costs would be much higher for cancer, CHD, and stroke, and only slightly higher for dementia, as the onset of dementia is mostly likely to occur at older age. The information provided in the paper is insufficient to estimate the magnitude of this effect. Similarly, women in their 50s who care for a parent often do not resume work after the parent dies. Including these potential losses of work hours as productivity losses could increase the estimated burden of informal care by seven times.
These points should not be interpreted as a claim that the calculations in the paper by Landeiro and colleagues are wrong. Instead, they illustrate how different reasonable methodological choices can lead to vastly different estimates. The authors have contributed to the scientific community by explaining their methodological choices and providing detailed calculations of the components. This transparency will allow others to perform calculations similar to those that we have shown in this Comment, to understand the sensitivity of the results to different methodological choices.”
Full editorial, J Lee. The Lancet: Health Longevity, 2024.7.25