Scottish Government

Previous Scottish Health Surveys were undertaken in 1995, 1998, 2003, 2008 and 2009. The continuous Scottish Health Survey began in January 2008 and is now running continuously (ie annually) from 2008 - 2011. Time series analysis is usually conducted over equally spaced time intervals, therefore monitoring change over time is possible from 2008 onwards as the data is now collected annually. Monitoring change over a greater time period, eg from 1995, is feasible, however, care should be taken when interpreting the results. See also our section on producing confidence intervals.

For more information on monitoring change over time see the Useful Website section below.

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Menu - monitoring change over time

• analysis pitfalls
• analysis by deprivation
• analysis by NHS Health Boards
• analysis by key topics

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Prior to embarking on analysis of Scottish Health Survey data over time, check for any changes in the survey variables being analysis, changes in methodology, sampling or sample design which could invalidate analysis. For specific details on change over time see our section on time series analysis in Tips Before Starting Data Analysis and the sections below.

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Whilst there have been changes to the SIMD methodology and indicators used over the three versions of the SIMD (2004, 2006, 2009) it is still possible to look at change over time though care needs to be taken because of the changes. The version or versions of the SIMD index to use will depend on the purpose of the analysis being carried. Guidance on performing analysis over time is available, in addition to further information on the background, methodology and development of SIMD, plus some general FAQS which cover what the SIMD can and cannot be used for.

For analysis of Scottish Health Survey data by SIMD quintiles over time we give below the year of the Scottish Health Survey, the corresponding SIMD quintile variable name found in the dataset, and the version of SIMD this variable is based upon. Note that for the 1998 and 1995 surveys, deprivation was measured using the Carstairs Index. The corresponding Carstairs quintile variables are CARGP5 (1995) and CARSTG5 (1998).

Monitoring change by deprivation - SHeS variable names

Please contact the Scottish Health Survey Team if you require any help on conducting analysis over time by deprivation.

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In 2006 there was an adjustment to the administrative boundaries of NHS Greater Glasgow and NHS Highland and dissolution of NHS Argyll and Clyde. Hence from 2008, analysis by NHS Board should be based upon the revised NHS Health Board boundaries. Therefore, results from the 1998 and 2003 surveys by NHS Board must be adjusted to reflect the revised Health Board boundaries which will enable comparisons with data post-2003 by NHS Board. Please contact the Scottish Health Survey Team for further guidance on this type of analysis.

However, it should be noted that the 2008-2011 Scottish Health Survey is designed to be representative at the Health Board level for all Boards, but only after four years of data are collected, ie results available in 2012. Prior to this, producing results by NHS Board is only possible for a minority Boards, and will also depend on the breakdown of analysis required. See also our analysis by Health Board section.

Note that estimates produced from the 1995 survey by NHS Board are unavailable due to the change or deletion of postcodes since 1995.

For the latest published results by NHS Board:

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Alcohol consumption

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In terms of monitoring change over time relating to alcohol consumption, the most notable recent changes are:

• the updated alcohol conversion factors - these are used to convert drinks into units of alcohol, as surveys have increasingly underestimated the level of alcohol consumption by not taking account of increased strength and size of some drinks.
• modifications to daily drinking thresholds for men and women, used to define daily unit consumption in excess of recommendations.

As a result, the revised estimates of alcohol consumption from the 2003 Scottish Health Survey data was published in 2008 and the corresponding revised alcohol consumption variables added to the 2003 dataset. Therefore monitoring change over time in relation to alcohol consumption is possible from 2003 onwards.

Also refer to our section on Data Issues by Topic.

Physical activity

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Adult Physical Activity

The current physical activity recommendations are that adults participate in 30 or more minutes of moderate or vigorous activity on at least 5 days a week. Government recommendations state that physical activity can be accumulated in bouts as short as 10 minutes. The Scottish Government's current physical activity target is that 50% of adults will be participating in this level of activity by the year 2022.

In terms of the Scottish Health Survey, some changes to the way that adult physical activity is measured were introduced in 2008. The main change was that prior to 2008 activities were recorded if that lasted at least 15 minutes; from 2008 onwards activities of 10-14 minutes duration were also included in the analysis. The 2008 chapter on physical activity concluded that the impact of this change on the trend in the proportion of men and women meeting the physical activity recommendations above was small overall. When making comparisons with physical activity results from the 1998 and 2003 surveys, analysis should be based on activities accumulated in bouts of 15 minutes. From 2009 onwards, the trends will be based on the 10 minute definition and will take the 2008 estimates as the baseline for the time series.

The adult physical activity module included in the survey from 1998 onwards is based on the Allied Dunbar National Fitness Survey, a major study of physical activity among the adult population in England conduced in 1990.

Note that the physical activity results from the 1995 Scottish Health Survey questionnaire are not comparable with the subsequent surveys. Therefore when making comparisons of results over time relating to physical activity of adults, analysts should use the datasets from 1998 onwards. Note that adults aged 16-74 year were eligible for interview in 1998, while from 2003 onwards adults aged 16+ were interviewed.

Child Physical Activity

The current physical activity recommendations are that children are active for at least 60 minutes on 7 days a day. The Scottish Government's current physical activity target is that 80% of children will be participating in this level of activity by the year 2022.

The questions on child physical activity included in the 1998, 2003, 2008 and 2009 questionnaire were based on the 1997 Health Survey for England children's physical activity module. Note that children were not interviewed in the 1995 survey.

Note school based activity was not measure in the 1998 and 2003 surveys - for more details on measuring child physical activity see our section on Data Issues by Topic.

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time series analysis - Scottish Government

Deprivation analysis - ISD - which SIMD version to use and recommendations for analysing trend data