TABLE 3.
C-statistics from Models Predicting High Statin Adherence (PDC ≥ 80%) Including Combinations of Measures of Previous Adherence and Patient Baseline Information in the Testing Cohort
| Variables Included in Each Model | C-statistics (95% CI) |
|---|---|
| Univariable models | |
| Refill count measures | |
| Any “no second fill” | 0.533 (0.529-0.537) |
| Median refills | 0.574 (0.569-0.580) |
| Mean refills | 0.575 (0.569-0.580) |
| Discontinuation measures | |
| Any discontinuation | 0.587 (0.583-0.592) |
| Mean TTD | 0.625 (0.620-0.630) |
| Coverage measures | |
| Min CMA | 0.614 (0.608-0.619) |
| Max CMA | 0.640 (0.635-0.646) |
| Median CMA | 0.639 (0.634-0.644) |
| Mean CMA | 0.640 (0.635-0.646) |
| Min CMG | 0.661 (0.656-0.666) |
| Max CMG | 0.629 (0.623-0.634) |
| Median CMG | 0.659 (0.654-0.665) |
| Mean CMG | 0.657 (0.651-0.662) |
| Min PDC | 0.633 (0.628-0.639) |
| Max PDC | 0.666 (0.661-0.671) |
| Median PDC | 0.665 (0.659-0.670) |
| Mean PDC | 0.663 (0.658-0.668) |
| Clinical variables + previous adherence measuresa | |
| a. All baseline information + median CMA | 0.684 (0.679-0.689) |
| b. All baseline information + mean CMA | 0.685 (0.680-0.690) |
| c. All baseline information + median PDC | 0.694 (0.689-0.699) |
| d. All baseline information + mean PDC | 0.695 (0.690-0.700) |
| e. All baseline information + mean PDC + mean refills | 0.696 (0.691-0.701) |
| f. All baseline information + mean PDC + DD | 0.695 (0.690-0.700) |
| g. All baseline information + mean PDC + DD + no second fill + mean TTD + mean CMA | 0.696 (0.691-0.701) |
| Pharmacy-based data components | |
| h. Demographics + medication use + index statin information + medication burden + mean PDC | 0.687 (0.682-0.692) |
a “All baseline information” includes all variables listed in Table 2: patient demographics, health services use, comorbidities, medication use, index statin information, medication burden, and financial burden.
c-statistics = concordance statistics; CI = confidence interval; CMA = continuous measure of medication acquisition; CMG = continuous measure of medication gaps; DD = discontinuation (dichotomous); max = maximum; min = minimum; PDC = proportion of days covered; TTD = time to discontinuation.