Absolute Risk Prediction of Subsequent Cardiovascular Events in a Large Cohort of Elderly Australians with Hypertension
Estimating absolute risk, the risk of having an event over a specified period of time (usually five or ten years), is the best way to identify those most at risk of having a heart attack and stroke and therefore who would most likely benefit from lifestyle change or drug therapy. The commonly used calculators used for this purpose are based on the equations generated from observing since the late 1940s, the heart attack and stroke rates of citizens in the town of Framingham, Massachusetts, USA. These scores have been proven to be very useful but do have problems in special groups not represented in that population, for example Australian aborigines whose risk is under-estimated. Another more common problem is that no persons over 70 years were included in the study population. Indeed more than 50 per cent of this population were aged less than 50 years.
The Second Australian National Blood Pressure study (ANBP2) was conducted by us and others between 1995 and 2001. Most of the 6083 participants were followed for four years. These participants were aged 65-84 years at the time of trial entry. During the study period 1431 of the participants had a heart attack or stroke or died.
Using available risk calculators and the results of the ANBP2 trial we wish to calculate the heart attack and stroke risk of all ANBP2 participants at study entry and see how this fits with the actual events observed at the end of the clinical trial and at ten years follow-up. Given that we have already collected much of the data necessary and we can develop a preliminary risk calculator from a post hoc analysis of ANBP2, the cohort study would provide the perfect opportunity to test and refine this calculator with a longer follow-up period. The end would result in a more appropriate risk assessment based on an older, contemporary population from Australia.
This project is a participant based study
- Associate Professor Chris Reid - Monash University
- Associate Professor Philip Ryan - University of Adelaide
- Dr Andrew Tonkin - Monash University
- Professor Lindon Wing - Flinders University, South Australia