For right-censored or complete data, you can use survival probabilities in nonparametric
distribution analysis with the Kaplan-Meier estimates to calculate the
median, the first quartile (Q1), and the third quartile (Q3):
- The median is the time associated with the first survival
probability in the table less than or equal to 0.50.
- Q1 is the time associated with the first survival probability in
the table less than or equal to 0.75.
- Q3 is the time associated with the first survival probability in
the table less than or equal to 0.25.
For example, suppose you have the following output:
Nonparametric Distribution Analysis: Temp100
Censoring
| Uncensored value | 34 |
|---|
| Right censored value | 6 |
|---|
Characteristics of Variable
| 95.0% Normal CI |
|
|
|
|
|---|
| 44.7813 | 4.43366 | 36.0914 | 53.4711 | 24 | 38 | 54 | 30 |
|---|
- Median = 38
- The first survival probability in the table that is less than or equal to 0.50 is 0.475. The time associated with this survival probability is 38; therefore, the median is 38.
- Q1 = 24
- The first survival probability in the table that is less than or equal to 0.75 is 0.75. The time associated with this survival probability is 24; therefore, Q1 is 24.
- Q3 = 54
- The first survival probability in the table that is less than or equal to 0.25 is 0.25. The time associated with this survival probability is 54; therefore, Q3 is 54.
If the survival probability cannot be found in the table, then the quartile or median value is displayed as an *. For example, in the following table, there is no survival probability less than or equal to 0.25, so Q3 is *.
Nonparametric Distribution Analysis: Temp80
Censoring
| Uncensored value | 37 |
|---|
| Right censored value | 13 |
|---|
Characteristics of Variable
| 95.0% Normal CI |
|
|
|
|
|---|
| 63.7123 | 3.83453 | 56.1968 | 71.2279 | 48 | 55 | * | * |
|---|
