University of Dundee Cardiovascular Epidemiology Unit Why Scotland is adding Social Deprivation and Family History to cardiovascular risk assessment in the ASSIGN score H. Tunstall-Pedoe
University of Dundee Cardiovascular Epidemiology Unit 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 Men curve 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,
SHHEC ASSIGN Age last birthday: 52 years Sex : enter "M" or "F" m SIMD score 1.1 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 17 FramCV 27 Authors: Mark Woodw ard and Hugh Tunstall Pedoe,
SHHEC ASSIGN Age last birthday: 52 years Sex : enter "M" or "F" m SIMD score 85 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 27 FramCV 27 Authors: Mark Woodw ard and Hugh Tunstall Pedoe,
SHHEC ASSIGN Age last birthday: 58 years Sex : enter "M" or "F" f 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 25 Authors: Mark Woodw ard and Hugh Tunstall Pedoe,
SHHEC ASSIGN Age last birthday: 58 years Sex : enter "M" or "F" f SIMD score 1.1 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 16 FramCV 25 Authors: Mark Woodw ard and Hugh Tunstall Pedoe,
SHHEC ASSIGN Age last birthday: 58 years Sex : enter "M" or "F" f SIMD score 85 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 31 FramCV 25 Authors: Mark Woodw ard and Hugh Tunstall Pedoe,