The health-hazard appraisal is based on statistical tables collected and developed
over the past 20 years by Dr. Lewis C. Robbins of Health Hazard Appraisal, Inc., in Indianapolis, and Dr. Jack H. Hall of Methodist Hospital in Indianapolis.
From the now-famous Framingham study, which involved monitoring the health and
life-styles of 5200 residents of that Boston suburb, and from other long-term studies, they have rated the importance of each major health risk. Analysis of the results showed, for example, that a man with a serum-cholesterol reading of 240 is three times as likely to have a heart attack as one with a reading below 200, and that someone with a systolic blood pressure of 160 runs four times the risk of one below 120.
Next, from national mortality statistics, the doctors obtained the specific probability of death at each age. For every 100,000 men of age 40, for example, 5560 will die of all causes over the next ten years. To put it another way, the risk of dying in the next ten years for an average 4O-year-old man is 5.56 percent.
Finally, from other studies, they gathered facts on the average person's weight,
blood pressure, cholesterol, smoking habits and so on. Using data from all these sources, the doctors could now compute a person's life expectancy—based not just on his age, but also on the health risks present in his life-style. Consider a man of 40 who has high cholesterol, is overweight, had one parent who died young of heart disease, and displays several other factors known to increase the risk of dying. The doctors would first figure just how great his risk is, then compare it with the average risk for that age. Suppose such
calculations show a 14.3-percent chance of death in the next ten years. The tables
show that this is the risk of an average man of age 50. Thus, the 4O-year-old man,
through a combination of factors, has become, in terms of health hazards, a 5O-year-old. Of course, the analysis also shows how the subject could improve his odds and thus add years to his life.
