Table 2.
Comparing the prevalence, sensitivity, positive predictive value (PPV), and specificity of nine alternative claims-based definitions of antipsychotic polypharmacy
| Source | Parameters | Identified with polypharmacy | Prevalence | Sensitivity | PPV | Specificity |
|---|---|---|---|---|---|---|
| >14 days of polypharmacy | N | (%) | ||||
| Chart | 51 | (30.0%) | ||||
| Medicaid | Allowable gap: 32 days | 50 | (29.4%) | 92.16% | 94.0% | 98.47% |
| Allowable gap: 14 days | 46 | (27.1%) | 82.35% | 91.3% | 96.63% | |
| Allowable gap: none | 45 | (26.5%) | 82.35% | 93.3% | 96.63% | |
| >60 days of polypharmacy | ||||||
| Chart | 48 | (28.9%) | ||||
| Medicaid | Allowable gap: 32 days | 43 | (25.9%) | 83.33% | 93.0% | 97.03% |
| Allowable gap: 14 days | 36 | (21.7%) | 68.75% | 91.7% | 94.57% | |
| Allowable gap: none | 24 | (14.5%) | 50.00% | 96.0% | 91.64% | |
| >90 days of polypharmacy | ||||||
| Chart | 44 | (27.5%) | ||||
| Medicaid | Allowable gap: 32 days | 39 | (24.4%) | 81.82% | 92.3% | 99.25% |
| Allowable gap: 14 days | 32 | (20.0%) | 68.18% | 93.8% | 95.00% | |
| Allowable gap: none | 18 | (11.3%) | 40.91% | 100.0% | 91.16% |
Note: The Medical chart was the criterion standard (n = 312 medical records). The chart-based assessment did not allow for medication gaps in order to capture the duration of antipsychotic medications and polypharmacy as prescribed. Prevalence of the measures is calculated based on nine alternative definitions, using the medical chart-based measure to establish the denominator for individuals on antipsychotics for >14 (n = 170), >60 (n = 166), and >90 days (n = 160).