fractional days (also years) between ... episodes

The period between specified episodes of a case. The units can be in years, days, hours or minutes. For example, we might define the Calculated Value attributes:

DaysBtwnNumericHDL = fractional days between numeric HDL episodes

DaysBtwnAvailLDL = fractional days between available LDL 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          2.5          1.9

DaysBtwnNumericHDL                    19           10.11       107           17.85

LDL                       4.2          4.0          4.5                       3.8

DaysBtwnAvailLDL                      19           10.11                    124.85

Trig                      3.6                                    3.6

LipidDrug                 N                         Y            Y

This expression is useful for determining rates of change.

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

See also: Fractional days between first and subsequent … episodes.