Table 1. Characteristics of Prescription Drugs by Manufacturer Coupon Use Levela.
| Variable | All (n = 2501) | None (n = 1234) | Any (n = 1267) | t Test P value | Group by manufacturer coupon use frequency | |||
|---|---|---|---|---|---|---|---|---|
| 1st Quartile (n = 317) | 2nd Quartile (n = 317) | 3rd Quartile (n = 317) | 4th Quartile (n = 316) | |||||
| Mean percentage of claims with coupon use per drug, %, mean (SD) | 8.2 (16.6) | 0 | 16.3 (20.3) | NA | 0.6 (0.4) | 3.4 (1.5) | 14.9 (5.5) | 46.3 (17.3) |
| Patient-cost characteristics | ||||||||
| Mean total cost per patient per drug, mean (SD), $ | 10 002 (35 939)b | 7649 (33 901)b | 12 165 (37 601)b | .003b | 3593 (11 449) | 8115 (20 897) | 15 892 (43 077) | 21 533 (56 142) |
| Mean patient copay per claim before offset, mean (SD), $ | 222 (431)c | 247 (542)c | 205 (331)c | .03c | 142 (237) | 268 (1305) | 249 (376) | 267 (547) |
| 0 to ≤100, % | 51.1 | 56.3 | 47.4 | NA | 59.9 | 47.9 | 43.6 | 37.8 |
| 100 to ≤250, % | 28.0 | 22.1 | 32.3 | NA | 29.0 | 31.1 | 28.7 | 40.4 |
| 250 to ≤500, % | 11.0 | 9.7 | 12.0 | NA | 6.9 | 13.7 | 16.5 | 11.1 |
| >500 or more, % | 9.8 | 11.9 | 8.3 | NA | 4.1 | 7.3 | 11.3 | 10.8 |
| Drug characteristics | ||||||||
| Single-source drugs, No. (%) | 1426 (57.0) | 628 (50.9) | 798 (63.0) | <.001 | 154 (48.6) | 185 (58.4) | 227 (71.6) | 232 (73.4) |
| Me-too single-source drugs, No. (%) | 994 (39.7) | 434 (35.2) | 560 (44.2) | <.001 | 104 (32.8) | 133 (42.0) | 164 (51.7) | 159 (50.3) |
| Mean years since the FDA approval, mean (SD), y | 14.1 (9.1) | 17.0 (10.2) | 13.4 (8.6) | <.001 | 16.3 (9.3) | 15.0 (9.0) | 11.7 (7.5) | 11.6 (8.1) |
| Drug-class characteristics | ||||||||
| Mean prevalence of coupons among in-class competitors, mean (SD), % | 16.3 (15.3) | 15.0 (15.0) | 18.6 (15.1) | <.001 | 16.2(14.0) | 15.3 (13.8) | 18.3 (15.2) | 24.2 (16.1) |
| Drugs in classes without generic competition, No. (%) | 425 (17.0) | 185 (15.0) | 240 (18.9) | .009 | 29 (9.2) | 74 (23.3) | 75 (23.7) | 62 (19.6) |
| Relative total cost per patient per drug to the class, mean, (SD)b | 1.00 (1.41) | 0.86 (1.62) | 1.13 (1.16) | <.001 | 1.05 (1.20) | 1.05 (1.01) | 1.17 (1.32) | 1.27 (1.06) |
| Relative patient copay to the drug class, mean (SD)b | 1.00 (1.21) | 1.12 (1.69) | 0.92 (0.69) | .001 | 0.80 (0.65) | 0.97 (0.81) | 0.97 (0.66) | 0.91 (0.57) |
Abbreviation: NA, not applicable.
a
Analysis of data for October 2017 through September 2019 from IQVIA Formulary Impact Analyzer.
b
Calculated without drugs that cost more than $600 000 (0 in “any” group, 5 in “none” group) to mitigate the influence of extreme outlying values on the mean. Before exclusion: 12 164 [SD, 37 601, any] vs 11 019 [SD, 61 030, none], P = .59.
c
Calculated without drugs that had mean copay more than $5000 (3 in “any” group, 7 in “none” group) to mitigate the influence of extreme outlying values on the mean. Before exclusion: 231 [SD, 744, any] vs 411 [SD, 277, none], P = .03.