North of Scotland Public Health Network Horizon Scanning Project David Kerr, NHS Shetland

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1 North of Scotland Public Health Network Horizon Scanning Project David Kerr, NHS Shetland GROS Population Projections As can be seen from the following graphs, the North of Scotland Public Health Network Boards are predicted to go through quite severe changes in population demographics over the coming 25 years. Overall, populations are predicted to be on the increase (with the exception of Shetland and the Western Isles) as can be seen from Figs 1 & 2. This is driven largely by people living longer, and as a result all areas are predicted to have an increasingly elderly population (highlighted in red in Figs 3-10). For Scotland overall, this is predicted to show a 64.5% increase in the population aged 65 and over by For the North of Scotland Boards together, this figure rises to almost 72%. Sharp falls in the number of children (0-15) are predicted in Shetland (32.5%) and Western Isles (17.4%) as well as a falling number of people in the younger, economically active age groups. For year olds Shetland is predicted to reduce by 35% and the Western Isles by 21.8% and for year olds, Shetland is predicted to fall by 30.7% and the Western Isles by 25.1%. A similar pattern is predicted across the North of Scotland region, though it is not as pronounced in the other areas. If all these projections prove to be accurate, the changes will obviously have a significant impact on the economy, public sector services and particularly provision of care to the elderly across the region. It should be noted, GROS based population estimates and projections are based upon the last Census. Currently we are in the hiatus between the 2011 Census capture and its results being released, so any further projections are still based upon the 2001 Census. Since then, as we know, migration from eastern parts of Europe has been positive in certain parts of Scotland. However, this has made it difficult for GRO to make consistent migration assumptions. 1

2 Fig 1. Fig 2. 2

3 Fig 3. Scotland Overall 7.3% increase Fig 4. North of Scotland Public Health Network Boards verall 10.6% increase O 3

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5 Fig 5.NHS Shetland erall 7.5% decrease Ov Fig 6. NHS Western Isles Overall 4.1% decrease 5

6 Fig 7. NHS Orkney Overall 12.1% increase Fig 8. NHS Highland 6

7 Overall 10.8% increase Fig 9. NHS Grampian Overall 12.2 % increase 7

8 Fig 10. NHS Tayside Overall 10.1% increase 8

9 Limitations of GROS population projections It must be noted that these population projections have limitations. A projection is a calculation showing what happens if particular assumptions are made. The population projections are trend-based. They are, therefore, not policy-based forecasts of what the government expects to happen. Many social and economic factors influence population change, including policies adopted by both central and local government. The relationships between the various factors are complex and largely unknown. The effect of the assumptions about future migration, fertility and mortality is often limited by the inertia in population change and the future population of an area is strongly influenced by the initial base population. As the process of change is cumulative, the reliability of projections decreases over time. Change affects some populations more rapidly and more seriously than others. Thus, projections for areas with small populations tend to be less reliable than those for areas with large populations, because the former are usually affected more by migration. Projections of the number of adults (particularly elderly people) are usually more reliable than those for children because of difficulties in projecting levels of fertility and parental migration. The size of the migration flows, and the uncertainty of future trends, mean that for many areas the migration assumptions are more critical than the fertility and mortality assumptions. Hence the migration assumptions can have a large effect on small populations in the long-term (e.g. the islands) and also for some other areas with larger populations. Central government population projections set local and regional projected population patterns in a national context. They are trend-based. However, it should be remembered that new local planning policies are often intended to modify past trends. Structure plans may be based on reasoned and agreed departures from the projections that seem better placed to fit particular local circumstances. Consequences of GROS projections Population projections, like some other types of projections, may indicate that existing trends and policies are likely to lead to outcomes which are judged undesirable. If new policies are then introduced, they may result in the original projections not being realised. However, this means the projections will have fulfilled one of their prime functions, to show the consequences of present demographic trends with sufficient notice for any necessary action to be taken. 9

10 Accuracy of GROS projections GROS did a piece of work looking at past projections, comparing them with mid-year estimates. The results were published in 2006 and the key findings were: The estimated population at mid-2005 for Scotland was 5,098,400; projections for mid-2005, since the 1994-based set, ranged from a maximum of 5,113,870 in 1994 (0.4 per cent too high) to a minimum of 5,030,170 in 2002 (1.3 per cent too low); As would be expected the projection made most recently (2004-based) was the best in projecting the overall size of the population in The projection based on 2002 was the worst, as the trend based approach did not predict the historic rise in positive net-migration; Council areas where the trend has not changed tended to be projected better than those that have changed as the trend based approach does not pick up changes until they have taken place in the base data; The majority of the errors across Council areas for most of the projections for mid are between +/-6%; Errors in the migration assumptions contribute the most to the overall error, followed by errors in the base population for the majority of Council areas; Overall deaths tended to be better projected than births for mid-2005, possibly partly because of the greater interaction between migration and births; In some areas the errors in different components for some projections offset each other giving what overall would seem like a good prediction but is really only that because of chance; For all the time periods (i.e. projecting 2, 4, 6, and 8 years ahead) the age group which is predicted the least accurately across Council areas is 0-15 year olds, followed by years olds. The 65 years and older age group is predicted the best probably because they are less affected by errors in the base population, migration and fertility assumptions; Errors across Council areas are more spread out the further ahead the projection, especially for the 0-15 age group. The full report is available at: accuracy-sub-national-pop-proj-scotland.pdf As the projections are still based on many assumptions, similar inaccuracies are likely to be present in the more recent projections, including the 2008-based projections used in this paper. Projections are will become more accurate when 2011 Census results become available for use as baseline data. 10