The Framingham Risk Equation is a predictive equation borne out of the Framingham Heart Study, which started in 1948 and has been operational for more than 60 years. You can read about the Framingham Heart Study by clicking here
The Framingham Risk Equation was developed for several cardiovascular disease endpoints by Anderson and colleagues in 1991. The citations for the relevant scientific papers are:Anderson KM, Odell PM, Wilson PW, Kannel WB. Cardiovascular disease risk profiles. Am Heart J 1991; 121 (1 Pt 2): 293-298.Anderson KM, Wilson PW, Odell PM, et al. An updated coronary risk profile. A statement for professionals. Circulation 1991; 83: 356-362.
The Framingham Risk Equation that the NVDPA web calculator and paper-based risk charts are based on can be viewed in Appendix IV (page 113) of the systematic review report Technical report: review of the evidence and evidence-based recommendations for practice.