Table 1.
Equations of medication adherence measures involving secondary database analysis and pill count [15, 19, 27, 28].
| Measures | Equation |
|---|---|
| Medication Possession Ratio (MPR) | Days' supply obtained/refill interval or fixed interval |
|
| |
| Dichotomous variable | N/A (arbitrary cutoff value) |
|
| |
| Continuous, Multiple Interval Measure of Medication Acquisition (CMA) | Cumulative days' supply obtained over a series of intervals/total days from the beginning to the end of the time period |
|
| |
| Continuous, Multiple Interval Measure of Medication Gaps (CMG) | Cumulative days without any medication over a series of intervals/total days from the beginning to the end of the time period |
|
| |
| Continuous, Single Interval Measure of Medication Acquisition (CSA) | Days' supply obtained in each interval/total days in the interval |
|
| |
| Continuous, Single Interval Measure of Medication Gaps (CSG) | Number of days without any medication/total days in the interval |
|
| |
| Pill count | (Number of dosage units dispensed − number of dosage units remained)/(prescribed number of dosage unit per day × number of days between 2 visits) |