National Records of Scotland

Preserving the past, Recording the present, Informing the future

Increased Winter Mortality in Scotland, 2006/07

Increased Winter Mortality in Scotland, 2006/07

31 October 2007

Introduction

This section presents data on the seasonal increase in mortality recorded each winter in Scotland. For the information presented here, the increased winter mortality has been defined as the difference between the number of deaths in December – March and the average of the preceding (August – November) and following (April – July) non-winter periods.

Results

Table 1 summarises recent trends for Scotland. Provisional data shows that there were some 2,750 additional deaths in Scotland during the winter of 2006/07. This is almost 1,000 more than during the winter of 2005/06 when, with mild weather and no serious outbreaks of flu, the lowest ever figure of 1,790 was recorded. However, the 2006/07 figure is very close to the three previous winters and is around a half (53 %) of the total in 1999/2000, the last time influenza activity was at a high level.

Table 1 also shows the extent to which the winter increase in mortality affects the elderly, particularly those aged 75 and over.

Chart 1 shows that there has been a downward trend in the number of additional winter deaths over the last 50 years, though there have been a number of years with relatively high peaks. Generally, these peaks coincide with periods of high influenza activity. Table 2 gives the underlying figures for Chart 1.

Table 3 gives a more detailed breakdown by age and NHS Board area (as at 1 April 2006 following the dissolution of NHS Argyll & Clyde).

Table 4 shows the underlying data (death registrations) used to derive the measure of seasonal increase described above.

Note:
The files below have been made available as Excel spreadsheets and can be viewed in Comma Separated Value (CSV) or Adobe Acrobat Portable Document Format (PDF).

When opening the spreadsheet files your browser, depending on how it's been configured, will prompt to either open the file or save it to disk. 
Maximum file size is 156Kb.
Pdf files require Acrobat Reader. Download Acrobat Reader free Get Acrobat Reader

Table 1

Increased winter mortality by age group, Scotland, 1990/91 to 2006/07
(Excel    CSV    PDF)

Table 2

Increased winter mortality, Scotland, 1951/52 - 2006/07
(Excel    CSV    PDF)

Table 3

Increased winter mortality and increased winter mortality index, by age group and NHS Board area of usual residence, 1999/2000 to 2006/07
(Excel    CSV    PDF)

Table 4

Increased Winter Mortality in Scotland 1990/91 to 2006/07
(Excel    CSV    PDF)

Chart 1

Increased winter mortality, Scotland, 1951/52 to 2006/07
(Excel    PDF)

Discussion

Many studies have shown that mortality levels in Scotland are markedly higher in winter months than summer months. Moreover, there are indications that this increased winter mortality has been relatively high in Scotland (and the rest of the UK) when compared with many countries with more extreme winter climates, though UK levels are comparable to several southern European countries (e.g. Greece, Italy, Spain) and lower than those recorded in Portugal and the Republic of Ireland. Whilst a number of theories have been advanced to explain these observations, there is as yet no consensus on the underlying mechanisms involved.

In 2002, National Records of Scotland (NRS) published an Occasional Paper entitled 'The Raised Incidence of Winter Deaths'. As well as reviewing the various definitions used to assess the extent of increased winter mortality, this paper showed that additional winter deaths were particularly associated with respiratory and circulatory diseases and that few deaths were caused by hypothermia. It also demonstrated that, though not all increased winter mortality is related to influenza, there was a clear link between the number of additional deaths and the level of influenza activity.

Useful Link

See the Office for National Statistics (ONS) website for related data covering England and Wales. ONS plan to release data for 2006/07 later this year.