National Health Insurance
Theories of Future Changes in Mortality and Morbidity
Download full PDF Document
As part of the evidence in the National Health Service Bed Inquiry in the United Kingdom, the London School of Hygiene and Tropical Medicine provided a report on how epidemiological and demographic changes might affect the future requirements for beds. The summary is relevant to the assumptions being made about future levels of chronic disease and the need for health facilities in South Africa.
“The report considers the literature on demographic change and trends in the health status of the population, the effect of demographic change on bed usage and possible other epidemiological changes. ... The ageing of the population is identified as the most important demographic trend likely to influence health and health care demand. Recent improvements in mortality at older ages have been substantial ... falling mortality has an increasingly important impact on population age structure and changes in death rates at older ages have come to play an increasingly important role in overall mortality change in developed countries.”
“Although improvements in mortality would seem to imply improvements in the health status of the total and the elderly population, this is not certain. The report presents three alternative theories:
-
As more people survive to older ages, a larger proportion of those with unfavourable health characteristics will survive. The suggested decline in mortality may be due therefore to medical interventions. Such interventions prolong the period of pre-death morbidity and disability rather than prolonging healthy life.
-
There will be a ‘compression of morbidity’ achieved through postponement of morbidity and disability, but no corresponding delay in the time of death.
-
The ‘dynamic equilibrium’ theory that suggests whilst the onset of degenerative diseases may be postponed, so is death, with the result that the period of life spent in poor health remains constant.
“International evidence regarding changes in morbidity over time is mixed. ... Overall the literature suggests that there is a decline in the level of serious disability but increases in reported limiting long-standing illness and measures of mild disability.”
“The use of hospital beds is strongly associated with age. As older patients also have longer hospital stays (and more re-admissions) it would seem clear that population ageing will lead to increased demand for hospital beds. Yet if hospital usage is associated with care close to death an ageing population may not imply more beds – beds will just be required later in life.”
“There have ... been increases in [mortality rates for] certain diseases over time, particularly for the older age groups. This is expected – deaths avoided in earlier age groups will lead to an increase in the population surviving to older ages, and lead to more deaths at these older age groups, so increasing the death rates.”
“Literature on the association between age and use of hospital beds usually concludes that demographic projections of hospital bed usage are likely to be flawed in that they assume age-specific rates of use will remain the same. However, changes in the age at which people die and in the length of terminal illness may lead to changes in these patterns of usage. Those dying at more advanced ages experience a shorter period of pre-death morbidity, in which case further gains in longevity might be associated with a reduction in demand for hospital usage in the last year of life. However, it is also possible that lower use among the very old reflects either the high proportions in this age group who are resident in institutions, who perhaps have a higher threshold for hospital admission, or age related rationing of services.”
“Several approaches may be taken to projecting demands for hospital beds. The demographic approach involves simply projecting forward current age and sex specific patterns of use. However the report notes that demographically based projections have a number of limitations, as there is debate about the extent and implications of changes in the age and cause distribution of morbidity and mortality.”
“For example, the analysis of the incidence and survival rates of some of the major cancers suggests that there will be a growing demand for bed days from cancer patients. What is not clear, given the need to take account of co-morbidity, competing risks and ‘substitute morbidity’ is whether those dying from specific cancers, for example, will require more hospital care than those dying from specific cardiovascular diseases.”
This is a complex topic for which little evidence has been gathered in South Africa. Researchers are advised to be aware of these possibilities in performing very long term projections of need. The impact of changes in medical practice and technology is an important influence which will impact any long-term projections. Over medium-term planning periods, the effects are not likely to be as important.
<< Back to NHI Project List
|
