Populations: The significance of demographic changes for the health of the population and its need for health and related services

1. The overwhelming influence on health service needs is the age structure of the population. This recognised in the UK, where NHS resources are allocated on the basis of age-weighted capitation.
   (http://www.dh.gov.uk/en/Managingyourorganisation accessed 25 July 2008)

   Locally, demand for hospital services may be even more extremely age-associated than the national weighted capitation formula allows for, with the very elderly being not only far more likely to be admitted but having longer lengths of stay¹.

   The ages which entail the highest levels of health care involvement are:

   • Neonatal and infancy, where advances in hygiene, treatment for infectious diseases, and immunisation have greatly reduced deaths in children, especially in the developed world,
   • Fertile years for women, particularly in the developed world, where pregnancy and childbirth has tended to be seen as a medical condition, requiring medical supervision and intervention, and
   • Old age, when multiple pathologies are common, healing tends to be slower, many treatments are palliative rather than curative, and the likelihood of an additional illness or condition arising increases with age.

   The expressed hopes of the founding father of the NHS that demand would fall as the population were treated earlier has proved to be naively optimistic. Instead people are living to ages where what had previously been uncommon conditions in a relatively small number of elderly people are becoming the dominant causes of illness and mortality.

   The combination of high birth rates post 1939-45 war ('baby boom generation'), combined with this group's lower fertility and access to contraception, became known as the 'demographic time bomb', as population scientists and planners foresaw the effect of extended life expectancy, increased proportions of retired elderly people, and smaller numbers of working age people, especially women, to act as carers or professional health care workers.

    

2. Another aspect of population structure affecting use of health care services is genetic/ethnic/cultural background. Within the UK, increasing proportion numbers of the population are of African descent, among whom a significant proportion suffers from sickle cell disease. It is believed that the sickle cell mutation confers some degree of immunity to malaria, but it also places increased demands on the haematological services of the NHS. Certain cultural practices can also have unexpected effects on health. The skeletal disorders rickets and osteomalacia arise from lack of vitamin D. The main source of vitamin D is the action of sunlight on human skin, and this is most efficient on paler skins, as the effect of melanin is to mitigate the process. The adoption of all covering dress, for religious reasons, has resulted in these diseases recurring among certain communities in the UK, especially where housing conditions do not allow for private gardens (where the cultural dress rules are relaxed). Sufficient vitamin D to make up the difference cannot be obtained from a normal diet, and experiments in supplementing margarine with vitamin D were abandoned when some people developed problems with calcium metabolism from excessive amounts of the supplement. It is possible for specific vitamin D supplementation to be prescribed medically, and the local guidelines for this should be revised if necessary to included consideration of religious dress.
    
3. A third influence on population structure and health arises from migration and the social status of migrants. Since the last census was held (2001) there have been important changes to the membership of the European Union, with many of the former East European states now full members, and their citizens legally permitted to travel and work as they wish within the other member states. Around 700,000 are believed to have come to the UK However, some countries, the UK among them, have place limits on their rights to work, and to avail themselves of benefits (including health benefits). In some parts of the newer states tuberculosis is endemic. This has resulted in a pool of unknown size of carriers of TB, unable or unwilling to declare themselves and seek treatment for fear of their presence or mode of living being declared illegal. Overall cases of TB in the UK were at their lowest in 1987, when just over 5,000 cases were notified. These have now risen to about 8,500 case per year. There is some concern also that strains of the disease resistant to most treatments have evolved, though there is insufficient evidence to attribute this to the changed population structure.
   (http://www.guardian.co.uk/society accessed 25 July 2008)

Reference

1. Goodyear OM, Watts C, Haste F, Applying information to support equity in Practice Based Commissioning, 234-240, Current Perspectives in Healthcare Computing 2006, BJHC Books 2006

© M Goodyear 2008