percent decrease from previous - Pacific Knowledge Systems

percent decrease from previous calculates the percent decrease from the previous value to the current value. For example, given the following case fragment:

           01 Jun 03    20 Jun 03    30 Jun 03    15 Oct 03    02 Nov 03
HDL           2.0          2.1          2.2          2.2          1.7
LDL                        4.5          4.7                       3.1
Trig          3.6                                    3.6
LipidDrug     N                         Y            Y

percent decrease from previous HDL is 23`

percent decrease from previous LDL where LDL is numeric is 34

percent decrease from previous HDL where LipidDrug is “Y” is 0