fractional days (also years) between first and subsequent ... episodes

The period between the first episode and subsequent ones for specified episodes in a case. The units can be in years, days, hours or minutes.

For example, we might define a Calculated Value attribute:

DaysSinceFirstHDL = fractional days between first and subsequent numeric HDL episodes

This would appear in a case as follows:

                   01 Jun 03    20 Jun 03    30 Jun 03    15 Oct 03    02 Nov 03
                     17:29        17:33        20:06        20:06        17:33

HDL                   2.0          2.1          2.2                       1.9

DaysSinceFirstHDL                 19           29.11                    153.96

Trig                  3.6                                    3.6

LipidDrug             N                         Y            Y

This function can also be used for determining rates of change.

Note: You need to qualify the attribute name with ‘numeric’, ‘available’ or a similar expression.