| Abstract |
The objective of a medical follow-up study is generally to determine the effectiveness of each of several treatments by analyzing the responses of the patients. Frequently the response data coming out of these investigations is time to death of patients who are not otherwise lost to the follow-up of our investigation. The statistical nature of this data are characterized in this report. By definition the, 'Force of mortality or mortality rate function', is the rate associated with the probability of the patients' death in a specified short interval of time, given that the patient has survived to this instant in time. Mathematical models are presented which, as special cases, represent constant, increasing and decreasing mortality rates, along with combinations of these properties. Usually, these mortality rate curves are 'U' shape. The first part of the curve corresponds to infantile mortality, the second part corresponds to useful life, and finally, the last part corresponds to decay, aging, etc., culminating in death. |
