THE NEW ZEALAND MEDICAL JOURNAL Vol 116 No 1185 ISSN 1175 8716 NZMJ 7 November 2003, Vol 116 No 1185 Page 1 of 9 URL: http://www.nzma.org.nz/journal/116-1185/662/ © NZMA Framingham Heart Study risk equation predicts first cardiovascular event rates in New Zealanders at the population level Richard Milne, Gregory Gamble, Gary Whitlock and Rodney Jackson Abstract Aim To establish the population-level predictive validity of the Framingham Heart Study risk equation used to derive cardiovascular disease risk-prediction charts for New Zealand management guidelines on raised blood pressure and dyslipidaemia. Methods During 1992–3, standard cardiovascular risk factors were measured in a cohort of 6354 people (4638 men and 1716 women) aged 35–74 years with no history of cardiovascular disease, who were either enrolled on Auckland general electoral rolls or employed by a nationwide multi-industry corporation. Five-year cardiovascular event rates were predicted for the cohort using a Framingham risk equation and were compared with observed five-year cardiovascular event rates for hospitalisation and mortality. Results Incident cardiovascular hospitalisations or death were reported for 411 cohort participants (325 men and 86 women) during five years of follow up. There was good agreement between observed and predicted five-year cardiovascular event rates in all five-year age/sex categories up to 69 years. The risk equation tended to underestimate risk slightly in men and overestimate risk slightly in women up to 69 years, while in 70- to 74-year-olds it was accurate for men. Its accuracy in older women is uncertain. Conclusion A Framingham Heart Study risk equation used to estimate incident cardiovascular events in individuals without previous cardiovascular disease accurately predicts five-year risk of hospitalisation or death from a first cardiovascular event in New Zealand men aged 35–74 and women aged 35–69 years at the population level. Cardiovascular disease risk charts, based on a risk-prediction equation developed by the Framingham Heart Study collaborators, 1 are integral to New Zealand guidelines on the management of dyslipidaemia and raised blood pressure. 2,3 This risk equation was designed to predict incident cardiovascular end points and was developed from biennial medical examinations of a cohort of mainly white Americans living in the town of Framingham, Massachusetts in the 1970s and 1980s. 1 Although the risk charts have been used in New Zealand since 1992 and various Framingham risk equations and associated risk scores have been validated in several populations and ethnic groups internationally, 4,5 it is not known how well the equations predict population risk in New Zealand. The objective of this study was to establish the accuracy of the Framingham risk equation at a population level, by applying the equation to a New Zealand cohort and comparing predicted event rates with observed event rates by five-year age groups in men and women.