Trends in adult cardiovascular disease risk factors and their socio-economic patterning in the Scottish population 1995–2008: cross-sectional surveys

Abstract

Objectives

To examine secular and socio-economic changes in cardiovascular disease risk factor prevalences in the Scottish population. This could contribute to a better understanding of why the decline in coronary heart disease mortality in Scotland has recently stalled along with a widening of socio-economic inequalities.

Design

Four Scottish Health Surveys 1995, 1998, 2003 and 2008 (6190, 6656, 5497 and 4202 respondents, respectively, aged 25–64 years) were used to examine gender-stratified, age-standardised prevalences of smoking, alcohol consumption, physical activity, fruit and vegetable consumption, discretionary salt use and self-reported diabetes or hypertension. Prevalences were determined according to education and social class. Inequalities were assessed using the slope index of inequality, and time trends were determined using linear regression.

Results

There were moderate secular declines in the prevalence of smoking, excess alcohol consumption and physical inactivity. Smoking prevalence declined between 1995 and 2008 from 33.4% (95% CI 31.8% to 35.0%) to 29.9% (27.9% to 31.8%) for men and from 36.1% (34.5% to 37.8%) to 27.4% (25.5% to 29.3%) for women. Adverse trends in prevalence were noted for self-reported diabetes and hypertension. Over the four surveys, the diabetes prevalence increased from 1.9% (1.4% to 2.4%) to 3.6% (2.8% to 4.4%) for men and from 1.7% (1.2% to 2.1%) to 3.0% (2.3% to 3.7%) for women. Socio-economic inequalities were evident for almost all risk factors, irrespective of the measure used. These social gradients appeared to be maintained over the four surveys. An exception was self-reported diabetes where, although inequalities were small, the gradient increased over time. Alcohol consumption was unique in consistently showing an inverse gradient, especially for women.

Conclusions

There has been only a moderate decline in behavioural cardiovascular risk factor prevalences since 1995, with increases in self-reported diabetes and hypertension. Adverse socio-economic gradients have remained unchanged. These findings could help explain the recent stagnation in coronary heart disease mortalities and persistence of related inequalities.

Article summary

Article focus

• In Scotland, as in other developed countries, coronary heart disease mortality has declined substantially over time.

• This decline may now be slowing among younger groups, and there are still large inequalities in mortality between socio-economic groups.

• This study examined secular and socio-economic changes in cardiovascular disease risk factor prevalences in the Scottish population.

Key messages

• In Scotland, over a 13-year period since 1995 there have been at best only moderate declines in the prevalence of behavioural risk factors and no change in their socio-economic patterning, notably for smoking and poor diet.

• There has, however, been an increase in self-reported conditions predisposing to cardiovascular disease.

• This threatens to maintain inequalities in coronary heart disease mortalities and stifle further declines in mortality.

Strengths and limitations of this study

• This study utilised data from nationally representative surveys conducted over a 13-year period.

• The declining response levels to these surveys are of concern, possibly introducing bias. However, differential non-response by the socio-economically disadvantaged may lead to an underestimation of the magnitude of inequalities.