Comparison of pharmacy-based measures of medication adherence

Table 1 Summary of study measures

Defn	start of window to first dispensing	last dispensing to end of window	Timing^{^}	Description of Measure
CMA1	ignored	ignored	ignored	(# days dispensed, excluding last) / (first to last dispensing)
CMA2	ignored	counted	ignored	(# days dispensed, including last) / (first dispensing to end of window)
CMA3	ignored	ignored	ignored	minimum (CMA1, 1)
CMA4	ignored	counted	ignored	minimum (CMA2, 1)
CMA5	ignored	ignored	counted	(# days theoretical use^#) / (first to last dispensing)
CMA6	ignored	counted	counted	(# days theoretical use^#) / (first dispensing to end of window)
CMA7	counted	counted	counted	(# days theoretical use^#) / (start to end of observation window), includes in numerator meds carried into observation window
CMA8	counted	counted	counted	(# days theoretical use^#) / (lagged* start of obs’n window to end of window), numerator and denominator ignore intial lag period

^{^}refers to whether the timing of the dispensing (actual date dispensed) is taken into account in the calculations or is ignored.
^#assumes medications taken as directed and new medications “banked” until needed.
*lag refers to initial period covered by medication supply on hand at start of observation window. Medications dispensed during lag interval are “banked” and counted starting with end of lag.

ISSN: 1472-6963