assessment in the assign score to cardiovascular risk · to cardiovascular risk assessment in the...

Cardiovascular Epidemiology Unit

University of Dundee

H. Tunstall-Pedoe

Why Scotland is adding Social

Deprivation and Family History

to cardiovascular risk

assessment in the ASSIGN

score

Cardiovascular Epidemiology Unit

University of Dundee

on behalf of SIGN working group

on risk estimation

SOCIAL DEPRIVATION =

SIMD

(Scottish Index of Social

Deprivation)

Postcodes 208,609

Range of SIMD for postcodes

= 0.94 to 89.09

Mean 21.21, STD 16.32,

Median 16.28.

SIMD LOOK-UP TABLE

AB1 0NA 9.06

AB1 0NB 9.37

AB1 0ND 9.37

AB1 0NE 4.36

AB1 0NJ 6.65

AB1 0NL 6.65

AB1 0NN 9.84

AB1 0NP 6.65

AB1 0NQ 4.36

Etcetera 208, 600 more!!!

Millionaires’ row

Hermitage Drive, Edinburgh,

EH10 6BZ SIMD = 1.14

Social deprivation row

Torr St, Possil, Glasgow

G22 5EE SIMD = 87.61

ASSIGN

“ASSessing cardiovascular risk

using SIGN guidelines to ASSIGN

preventive treatment”

SIGN= Scottish Intercollegiate

Guidelines Network

Further information

• Website

assign-score.com

• Publications

Heart 2006; 92: 307-10

Heart 2007; 93: 172-6

Purpose

• First premiss The purpose of cardiovascular risk scores is not primarily the prediction of individual risk.

• Second premiss It is to prioritize giving preventive treatment to those at greatest risk.

• Third premiss Scores are inherently discriminatory but need to discriminate fairly.

Purpose

• Fourth premiss This means that everyone above the chosen cut-point for preventive treatment should be at higher risk than everyone below it.

• Fifth premiss Social and ethnic variation in cardiovascular risk is inadequately explained by classic cardiovascular risk factors

Purpose

• Sixth premiss If cardiovascular risk

scoring is to be applied to whole

populations it may need to take account of

social and ethnic heterogeneity within

those populations.

Questions

• Question one Is the Framingham

cardiovascular score fair (or equitable)

when used across a socially

heterogeneous population ?

• Question two Can we devise a more

socially equitable cardiovascular risk score

which performs better than Framingham ?

Methods

• Scottish Heart Health Extended Cohort

(SHECC):random population samples

recruited 1984-95

• Identification of Scottish Index of Multiple

Deprivation (SIMD) from postcode

(=Zipcode) of address at recruitment.

Methods

• Follow-up of mortality and morbidity

through national registries and record

linkage.

• Cardiovascular mortality and hospital

diagnoses of CHD, CBVD, and TIA to end

of 2005 (= 10-20 years follow-up)

Methods

• Calculation of observed rates by fifths of

SIMD score. Expected rates calculated

from Framingham cardiovascular score.

• Compare them to assess performance of

Framingingham score with respect to

social equity.

Question one results

• 6540 men, 1604 developed CVD, 743

within 10 years

• 6757 women, 1015 developed CVD, 422

within 10 years

CVD 10y risk percent

Framingham O & E

Men O RR E RR O/E RR

1 7.5 1.0 13.5 1.0 0.6 1.00

2 10.7 1.4 15.5 1.1 0.7 1.26

3 11.5 1.6 15.4 1.1 0.8 1.35

4 11.5 1.6 17.0 1.3 0.7 1.23

5 13.8 1.9 17.5 1.3 0.8 1.43

Women

1 2.0 1.0 6.7 1.0 0.3 1.00

2 3.3 1.6 8.3 1.2 0.4 1.32

3 5.2 2.6 9.2 1.4 0.6 1.87

4 7.5 3.7 10.0 1.5 0.8 2.45

5 9.6 4.7 11.9 1.8 0.8 2.66

Results Question One

• Compared with the population mean, use

of the standard Framingham score results

in undertreatment of the socially deprived

and overtreatment of the socially

advantaged. It is therefore unfair.

• The effect is relatively greater in women

than men, the former having a greater

social gradient (relatively) in disease.

Methods Question Two

• Use the same database to derive a risk

score incorporating deprivation with the

classic risk factors and any others that

prove significant when tested.

• Compare performance of the new ASSIGN

score with the Framingham cardiovascular

score within the SHHEC cohort.

Methods Question 2

• Cox proportional hazards model

• Test for linearity of risk factors

• Kaplan-Meier estimate of survival

• Observed versus expected, rank

correlation, Kappa statistics,

discrimination, area under ROC curve,

• HOTH graph

Results Question Two

• SIMD score was significant +

• Family history was significant +

• Cigarette dosage was significant +

• Left ventricular hypertrophy not so –

• Body mass index not so –

Results: Calibration

• Incidence (observed) = 11.7% (MEN)

• Framingham mean = 16.0%

• ASSIGN mean = 14.4%

• Framingham median = 13.6%

• ASSIGN median = 11.7%

Results: Calibration

• Incidence (observed) = 6.4% (WOMEN)

• Framingham mean = 9.6%

• ASSIGN mean = 9.3%

• Framingham median = 7.1%

• ASSIGN median = 6.2%

Results: comparison

• Rank correlation 0.92 in men, 0.90 in

women

• Kappa statistics:

at 20% cutoff 0.75 (0.71-0.79)

at 30% cutoff 0.59 (0.51-0.67)

Results: comparison

• Correct allocation in SHHEC cohort

• ASSIGN 83% at 20% cutoff

• Framingham 79% …….

• ASSIGN 96% at 30% cutoff

• Framingham 89%.........

Results: Area under the ROC

curve

Men 0.727 for ASSIGN

0.716 for Framingham

(p= 0.02)

Women 0.765 for ASSIGN

0.741 for Framingham

(p= 0.0001)

CVD 10y risk percent

ASSIGN O & E

Men O RR E RR O/E RR

1 7.5 1.0 11.0 1.0 0.7 1.00

2 10.7 1.4 12.3 1.1 0.9 1.29

3 11.5 1.6 13.0 1.2 0.9 1.31

4 11.5 1.6 15.0 1.4 0.8 1.14

5 13.8 1.9 17.8 1.6 0.8 1.15

Women

1 2.0 1.0 5.2 1.0 0.4 1.00

2 3.3 1.6 6.4 1.2 0.5 1.33

3 5.2 2.6 7.5 1.4 0.7 1.78

4 7.5 3.7 9.2 1.8 0.8 2.08

5 9.6 4.7 13.9 2.7 0.7 1.76

Cases treated or not % of whole

group at 20% treated overall

SIMD Fram +ve -ve ASSN +ve -ve

1 1.5 3.3 1.3 3.5

5 6.0 5.6 7.1 4.5

ALL 4.0 4.8 4.1 4.7

Conclusions

• Framingham and other current scores

ignore that component of social and

ethnic risk which is not mediated by the

classic risk factors.

• Through a deprivation score and family

history ASSIGN addresses deprivation

directly and ethnicity indirectly.

Conclusions

• ASSIGN and Framingham perform quite similarly in tests of discrimination: adding new powerful risk factors adds little to overall discrimination.

• ASSIGN is not therefore much better overall, but it is more equitable between social groups and is being adopted in Scotland for that reason.

Conclusions

• ASSIGN was designed for a Scottish

population but could be calibrated for

others which have an index of social

deprivation.

• Others are copying us (cf QRISK recent

BMJ) but we were the first to include a

measure of social deprivation.

Workload :% of SHHEC popn

above 20% 10y risk SIMD Fram ASSN

40-44 50-54 60-64 40-44 50-54 60-64

Men All 4.7 36 80 3.6 20 70

1 3.5 27 73 1.8 11 41

5 8.0 43 85 9.5 35 85

Women All 0.4 10 41 0.5 5.8 40

1 0.0 4.5 22 0.0 0.8 14

5 0.6 14 56 1.5 16 74

Further information

• Website

assign-score.com

• Publications

Heart 2006; 92: 307-10

Heart 2007; 93: 172-6

SHHEC ASSIGN Age last birthday: 52 years

Sex : enter "M" or "F" m

SIMD score 21.21

Family history:"Y" or "N"† n

Diabetes:"Y" or "N"† n

Current cig. smoker: "Y" or "N"§ y no/day 20

Systolic blood pressure (SBP): 140 mmHg

Total cholesterol 6.5 mmol/l

HDL cholesterol 1.2 mmol/l

SHHEC ‘ASSIGN’ score 19 FramCV 27

Authors: Mark Woodw ard and Hugh Tunstall Pedoe,



SIMD score 1.1











SIMD score 85










Sex : enter "M" or "F" f

SIMD score 21.21











SIMD score 1.1











SIMD score 85









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