Methodological assumptions of the CASSANDRA – REGICOR method

The CASSANDRA – REGICOR method for projection of coronary disease events at 10 years combines incidence and prevalence data obtained by the REGICOR investigators for Girona (Spain), extrapolated to the population of Catalonia, and the best Spanish data available. It is also possible to incorporate data from other Spanish sites.

The predictions include the number of expected cases of fatal and non-fatal acute myocardial infarction (AMI) and angina, and the incidence rate per 100,000 inhabitants by sex in the population aged 35-74 years in Girona, Catalonia and Spain.

The type of AMI considered in the projections is diagnosed without troponins; however, the prediction is expected to be sufficiently accurate because angina of all types is included.

The trends in AMI incidence rate are based on those observed in the REGICOR AMI register in Girona, Spain.

The extrapolation to the rest of Spain is based on the IBERICA study of AMI incidence and DARIOS study of cardiovascular risk factor prevalence in Spain.

The system extrapolates on the basis of the predictions for 2010 to 2020 with the Framingham-REGICOR adapted cardiovascular function, fitted with actual data from 1990 to 2006 in Girona, Spain.

The population demographic projections are provided by the official Catalan (IDESCAT) and Spanish (INE) institutes for government statistics.

The changes that users enter in the CASSANDRA – REGICOR electronic form refer to the expected / desired risk factor prevalence in 2020 by sex, and are expressed in percent units as follows:

1. Total cholesterol is categorized in 5 groups and the proposed change (only reductions are allowed) is assumed to occur in people with total cholesterol > 240 mg/dl following the proportion of population with total cholesterol observed in the 240 to 279 mg/dl and ≥280 mg/dl categories. The proposed reduction is assumed to result in an increase of the 200-239 mg/dl category alone. HDL cholesterol is assumed not to be susceptible to intervention.
2. Blood pressure (BP) is categorized in 5 groups and the proposed change (only reductions are allowed) is assumed to occur in people with BP ≥140-159/90-99 and ≥160/100 mmHg. The proposed reduction is assumed to result in an increase of the 130-139/85-89 mmHg category.
3. The proposed change (either a reduction or an increase) in the declared/observed diabetes prevalence is assumed to be applicable to the whole population.
4. Smoking change (either a reduction or an increase) in the declared prevalence is assumed to be applicable to the whole population.

Reductions greater than current risk factor prevalence are not allowed. Increases added to the current prevalence that result in prevalence >100% are not allowed.

AMI incidence is assumed to remain stable according to REGICOR data 1990-2006, and the number of cases as well as incidence in the basal model assuming no changes between 2010 and 2020 are influenced by demographic changes in the population age.

The results of the projections will be displayed in figures and tables with estimates for 2010, 2015 and 2020:

• Scenario assuming no intervention/no change in risk factor prevalence.
• Up to 3 alternative scenarios with interventions that result in prevalence changes entered by the system user and a simplified table with the prevalence evolution, population, and number of coronary disease cases 2010-2020.

Any intervention is assumed to affect and reach all the population aged 35-74 years in a similar manner and to reach 100% of the objectives.

To keep the projections as close to reality as possible, the population demographic projections are updated every 2 years and the incidence data with the periodicity of publication of new data.

Information sources: the following articles relate to the population data employed in the CASSANDRA-REGICOR system of projections:

• Wilson PWF, D’Agostino RB, Levy D et al. Prediction of coronary heart disease using risk factor categories. Circulation 1998; 97:1837-1847.
• D'Agostino RB, Grundy S, Sullivan LM et al. Validation of the Framingham coronary Heart Disease Prediction Scores: Results of a Multiple Ethnic Groups Investigation. JAMA 2001; 286: 180-187.
• Marrugat J, Solanas P, D’Agostino R, Sullivan L, Ordovas J, Cordón F, Ramos R, Sala J, Masià R, Rohlfs I, Elosua R, Kannel WB. Estimación del riesgo coronario en España mediante la ecuación de Framingham calibrada. Rev Esp Cardiol 2003; 56: 253-61.
• Marrugat J, D’Agostino R, Sullivan L, Elosua R, Wilson P, Ordovas J, et al. An adaptation of the Framingham coronary risk function to southern Europe Mediterranean areas. J Epidemiol Comm Health 2003; 57(8): 634-8.
• Ramos R, Solanas P, Cordón F, Rohlf I, Elosua R, Sala J, Masiá, Faixedas MT, Marrugat J, comparación de la función de Framingham original y la calibrada del REGICOR en la predicción del riesgo coronario poblacional. Med Clin (Barc) 2003; 121; 521-6.
• Marrugat J, Subirana I, Comín E, Cabezas C, Vila J, Elosua R, Nam BH, Ramos R, Sala J, Solanas P, Cordón F, Gené-Badia J, D'Agostino RB; VERIFICA Investigators. Validity of an adaptation of the Framingham cardiovascular risk function: the VERIFICA Study. J Epidemiol Community Health. 2007;61:40-7.
• Marrugat J, Sala J, Elosua R, Ramos R, Baena-Díez JM. Prevención cardiovascular: avances y el largo camino por recorrer. Rev Esp Cardiol. 2010; 63(Suppl 2): 49-54.
• Marrugat J, Vila J, Baena-Díez JM, Grau M, Sala J, Ramos R, Subirana I, Fitó M, ElosuaR. Relative Validity of the 10-Year Cardiovascular Risk Estimate in a Population Cohort of the REGICOR Study. Rev Esp Cardiol 2011. (in press)