Table 3. Price Differentials and Savings Estimates From Cost-Saving Generic-Generic Therapeutic Substitutionsa.
| Substitution type | Pairs, No. | Price differential, median (IQR) | Discount per drug pair, mean (SD), % | US dollars | ||
|---|---|---|---|---|---|---|
| Total spending, thousands (% of total) | Would-be spending, thousands (% discount) | Total savings, thousands (% of total savings) | ||||
| Same drug | ||||||
| Different manufacturer | 2 | 1.4 (1.1-1.6) | 23.5 (21.4) | 329.8 (4.4) | 255.3 (22.6) | 74.4 (1.1) |
| Different strength | 11 | 4.3 (2.2-26.7) | 77.1 (19.9) | 1372 (18) | 293.4 (78.6) | 1078.6 (16.3) |
| Different dosage form | 17 | 20.2 (13.7-70.9) | 94.9 (3.8) | 3006 (40) | 106.4 (96.5) | 2899.6 (43.8) |
| Different drug, same therapeutic class | 15 | 20.6 (11.3-45.5) | 93.9 (4.9) | 2789 (37) | 218.4 (92.2) | 2570.6 (38.8) |
| Overall | 45 | 15.6 (9.5-45.5) | 87.0 (19.0) | 7496 (100) | 873.7 (88.3) | 6622.3 (100) |
a
Source: Authors' analysis of the top-1000 generic drugs in the Colorado All Payer Claims Database and corresponding therapeutic alternatives. A total of drug pairs representing 45 high-cost generics and 64 therapeutic alternatives were examined. Would-be spending represents the estimated spending using the transaction prices of the therapeutic alternatives, assuming that all patients taking a high-cost generic would switch to the therapeutic alternative. When more than 1 therapeutic alternative was available for the same high-cost generic, we assumed that an equal proportion of people would switch to each alternative. Percentages may not add to 100% due to rounding.