Don't Allow Statistics To Dictate Your Treatment Choices - Understanding What Is Meant By Median Survival Statistics
When your doctor talks to you or you read about survival rates, for a type of cancer or a type of treatment you are being given a statistic. It is important to understand what statistics are and what they are not. They are nothing more than information about a group trend; they are NOT about you, an individual.
Never assume that a statistic will foretell your experience. It will not. You are one, an individual; you are not a group trend.
Researchers and the medical community talk about survival statistics, especially when they try to convey information to their patients and other professionals. They often do this by using a statistical term, or a group trend, including one, called the median.
Many people believe that a median is a different word for the average. Don’t be confused as a median is not the average, and more importantly, it does not predict what will be the experience of an individual, in this case, you!
A median is nothing more than the number that falls in the exact middle of a list of numbers. One-half of the numbers are lower than the median and one-half of them are higher.
To illustrate this concept, take the following list of numbers representing how many months a group of nine people lived after receiving a cancer diagnosis: 1, 1, 3, 4, 6, 14, 20, 40, 65.
The survival number in the middle or the statistical median is six months because there are four numbers lower (1, 2, 3 and 4) and four numbers higher (14, 20, 40 and 65). The median survival for people in this example after having received a diagnosis was six months, but the average survival was 17.1 months.
Note that there are four individuals (one-half of the group) of the nine who lived for many months beyond the median and three people lived well beyond the average of 17.1 months. Statistics do not tell you if you will be one of the 1-month survivors or if you will be the outlier of 65 months.
Scientists report the median, in this case, a 6-month survival, but the four individuals who beat the median lived much longer.
Survival curves are often characterized by a long tail just like the number set presented earlier in this article. Neither you nor your doctor knows where on the curve you will lie. Don't let median survival numbers convince you that you will have a limited life or discourage you from having a treatment.
