Measures of smoking, deprivation and cardiovascular risk
The effect of socio-economic deprivation on cardiovascular risk has
not been explained by differences in the prevalence of risk factors
traditionally used to estimate a person’s risk of developing
cardiovascular disease1. Two new risk scores, ASSIGN and QRISK, have
recently been developed to include measures of deprivation 2 3 in an
attempt to improve the prediction of risk using such scoring systems. One
potential factor contributing to the value of risk scores including
deprivation is that current smoking status (used in conventional scoring
systems) may not adequately reflect differences in lifelong smoking habit
in people of different socio-economic status.
We have therefore explored whether levels of lifelong smoking differ
by socio-economic status among current smokers. Analyses were based on
data for 3350 people aged 50-75 years participating in a primary
prevention trial of aspirin for asymptomatic atherosclerosis who had no
history of clinical cardiovascular disease but who were at moderately
increased risk of cardiovascular disease with an ankle brachial index
(ratio of systolic blood pressure in the ankle to that in the arm) of 0.95
or less4. Socio-economic status was assigned on the basis of postcode and
was defined by quintiles of the Scottish Index of Multiple Deprivation
(SIMD. SIMD is derived from Census data on income, employment, housing,
health, education and skills/training/access to services and
telecommunications 5. We used linear regression modelling to investigate
whether lifelong exposure to smoking as measured by pack-years of smoking
(number of cigarettes smoked per year multiplied by years of smoking/20)
varied by deprivation quintile after adjusting for age. Data for pack
years of smoking were square-root transformed in the analysis.
The mean age of the population studied was 62 years; 22% were in the
least deprived national quintile for deprivation and 27% were in the most
deprived quintile. Prevalence of current smoking increased from 13% for
the least deprived quintile to 36% to the most deprived quintile. Among
current smokers age-adjusted pack years of smoking increased from 30 to 34
(p=0.029 for trend) for the least to the most deprived quintile.
These findings suggest that current smoking status does not
adequately reflect differences in lifelong exposure to cigarette smoking
associated with deprivation. Risk scores such as the Framingham risk score
6 that only include current risk factor status may therefore not identify
the cardiovascular risk associated with deprivation appropriately 3;7;8.
As a consequence making treatment decisions based on scores that do not
include deprivation may result in a widening of health inequalities. Our
results support the importance of validating and refining scores that
include deprivation to address inequalities in risk of cardiovascular
disease.
Reference List
1. van Rossum CT, Shipley MJ, van de MH, Grobbee DE, Marmot MG.
Employment grade differences in cause specific mortality. A 25 year follow
up of civil servants from the first Whitehall study. J.Epidemiol.Community
Health 2000;54:178-84.
2. Woodward M, Brindle P, Tunstall-Pedoe H. Adding social
deprivation and family history to cardiovascular risk assessment: the
ASSIGN score from the Scottish Heart Health Extended Cohort (SHHEC). Heart
2007;93:172-6.
3. Hippisley-Cox J, Coupland C, Vinogradova Y, Robson J, May M,
Brindle P. Derivation and validation of QRISK, a new cardiovascular
disease risk score for the United Kingdom: prospective open cohort study.
BMJ 2007.
4. Heald CL, Fowkes FG, Murray GD, Price JF. Risk of mortality and
cardiovascular disease associated with the ankle-brachial index:
Systematic review. Atherosclerosis 2006;189:61-9.
5. Office of the Chief Statistician. Scottish Index of Multiple
Deprivation 2004: Summary Technical Report. 2004. Edinburgh, Scottish
Executive.
6. Anderson KM, Odell PM, Wilson PW, Kannel WB. Cardiovascular
disease risk profiles. Am.Heart J. 1991;121:293-8.
7. Brindle PM, McConnachie A, Upton MN, Hart CL, Davey SG, Watt GC.
The accuracy of the Framingham risk-score in different socioeconomic
groups: a prospective study. Br.J.Gen.Pract. 2005;55:838-45.
8. Tunstall-Pedoe H,.Woodward M. By neglecting deprivation,
cardiovascular risk scoring will exacerbate social gradients in disease.
Heart 2006;92:307-10.
Competing interests:
None declared
Competing interests:
No competing interests
20 July 2007
Sarah H Wild
Senior Lecturer
Marlene Stewart, Jacqueline Price, F.Gerald Fowkes, Gordon Murray.
Rapid Response:
Measures of smoking, deprivation and cardiovascular risk
The effect of socio-economic deprivation on cardiovascular risk has
not been explained by differences in the prevalence of risk factors
traditionally used to estimate a person’s risk of developing
cardiovascular disease1. Two new risk scores, ASSIGN and QRISK, have
recently been developed to include measures of deprivation 2 3 in an
attempt to improve the prediction of risk using such scoring systems. One
potential factor contributing to the value of risk scores including
deprivation is that current smoking status (used in conventional scoring
systems) may not adequately reflect differences in lifelong smoking habit
in people of different socio-economic status.
We have therefore explored whether levels of lifelong smoking differ
by socio-economic status among current smokers. Analyses were based on
data for 3350 people aged 50-75 years participating in a primary
prevention trial of aspirin for asymptomatic atherosclerosis who had no
history of clinical cardiovascular disease but who were at moderately
increased risk of cardiovascular disease with an ankle brachial index
(ratio of systolic blood pressure in the ankle to that in the arm) of 0.95
or less4. Socio-economic status was assigned on the basis of postcode and
was defined by quintiles of the Scottish Index of Multiple Deprivation
(SIMD. SIMD is derived from Census data on income, employment, housing,
health, education and skills/training/access to services and
telecommunications 5. We used linear regression modelling to investigate
whether lifelong exposure to smoking as measured by pack-years of smoking
(number of cigarettes smoked per year multiplied by years of smoking/20)
varied by deprivation quintile after adjusting for age. Data for pack
years of smoking were square-root transformed in the analysis.
The mean age of the population studied was 62 years; 22% were in the
least deprived national quintile for deprivation and 27% were in the most
deprived quintile. Prevalence of current smoking increased from 13% for
the least deprived quintile to 36% to the most deprived quintile. Among
current smokers age-adjusted pack years of smoking increased from 30 to 34
(p=0.029 for trend) for the least to the most deprived quintile.
These findings suggest that current smoking status does not
adequately reflect differences in lifelong exposure to cigarette smoking
associated with deprivation. Risk scores such as the Framingham risk score
6 that only include current risk factor status may therefore not identify
the cardiovascular risk associated with deprivation appropriately 3;7;8.
As a consequence making treatment decisions based on scores that do not
include deprivation may result in a widening of health inequalities. Our
results support the importance of validating and refining scores that
include deprivation to address inequalities in risk of cardiovascular
disease.
Reference List
1. van Rossum CT, Shipley MJ, van de MH, Grobbee DE, Marmot MG.
Employment grade differences in cause specific mortality. A 25 year follow
up of civil servants from the first Whitehall study. J.Epidemiol.Community
Health 2000;54:178-84.
2. Woodward M, Brindle P, Tunstall-Pedoe H. Adding social
deprivation and family history to cardiovascular risk assessment: the
ASSIGN score from the Scottish Heart Health Extended Cohort (SHHEC). Heart
2007;93:172-6.
3. Hippisley-Cox J, Coupland C, Vinogradova Y, Robson J, May M,
Brindle P. Derivation and validation of QRISK, a new cardiovascular
disease risk score for the United Kingdom: prospective open cohort study.
BMJ 2007.
4. Heald CL, Fowkes FG, Murray GD, Price JF. Risk of mortality and
cardiovascular disease associated with the ankle-brachial index:
Systematic review. Atherosclerosis 2006;189:61-9.
5. Office of the Chief Statistician. Scottish Index of Multiple
Deprivation 2004: Summary Technical Report. 2004. Edinburgh, Scottish
Executive.
6. Anderson KM, Odell PM, Wilson PW, Kannel WB. Cardiovascular
disease risk profiles. Am.Heart J. 1991;121:293-8.
7. Brindle PM, McConnachie A, Upton MN, Hart CL, Davey SG, Watt GC.
The accuracy of the Framingham risk-score in different socioeconomic
groups: a prospective study. Br.J.Gen.Pract. 2005;55:838-45.
8. Tunstall-Pedoe H,.Woodward M. By neglecting deprivation,
cardiovascular risk scoring will exacerbate social gradients in disease.
Heart 2006;92:307-10.
Competing interests:
None declared
Competing interests: No competing interests