Table. Demographic Characteristics of Filgrastim Usersa.
| Characteristics | No. (%) | Maximum SMDb | ||
|---|---|---|---|---|
| Filgrastim (originator) | Tbo-filgrastim | Filgrastim-sndz | ||
| No. of eligible beneficiaries | 86 040 | 19 083 | 9955 | |
| Age, y | ||||
| Mean (SD) | 71.0 (9.8) | 70.6 (10.1) | 72.0 (8.9) | 0.16c |
| <65 | 11 830 (14) | 3019 (16) | 1098 (11) | 0.14c |
| 65-74 | 44 009 (51) | 9675 (51) | 5096 (51) | 0.01 |
| 75-84 | 25 077 (29) | 5291 (28) | 3071 (31) | 0.07 |
| ≥85 | 5124 (6) | 1098 (6) | 690 (7) | 0.05 |
| Sex | ||||
| Male | 39 497 (46) | 8622 (45) | 4428 (44) | 0.03 |
| Female | 46 543 (54) | 10 461 (55) | 5527 (56) | 0.03 |
| Raced | ||||
| White | 72 421 (84) | 16 063 (84) | 8538 (86) | 0.04 |
| Black | 8052 (9) | 1735 (9) | 779 (8) | 0.05 |
| Other | 5567 (6) | 1285 (7) | 638 (6) | 0.01 |
| Census regione | ||||
| West | 15 640 (18) | 4567 (24) | 2187 (22) | 0.14c |
| Midwest | 18 395 (21) | 4725 (25) | 2122 (21) | 0.08 |
| South | 35 763 (42) | 6036 (32) | 4409 (44) | 0.26c |
| Northeast | 15 907 (18) | 3742 (20) | 1234 (12) | 0.20c |
| Unknown/other | 335 (<1) | 13 (<1) | 3 (<1) | 0.08 |
| Original Medicare statusf | ||||
| Aged (without ESRD) | 66 602 (77) | 14 129 (74) | 7984 (80) | 0.15c |
| Disabled (without ESRD) | 17 057 (20) | 4158 (22) | 1832 (18) | 0.08 |
| ESRD | 2381 (3) | 796 (4) | 139 (1) | 0.17c |
| Dual Medicare/Medicaid status | ||||
| Dual eligible | 13 319 (15) | 3260 (17) | 1406 (14) | 0.08 |
| Not dual eligible | 72 721 (85) | 15 823 (83) | 8549 (86) | 0.08 |
| Associated filgrastim indicationsg | ||||
| Nonmyeloid malignancy and chemotherapy | 61 863 (72) | 13 315 (70) | 7278 (73) | 0.07 |
| Acute myeloid leukemia and chemotherapy | 838 (1) | 204 (1) | 106 (1) | 0.01 |
| Nonmyeloid malignancy, chemotherapy, and bone marrow transplantation | 42 (<1) | 16 (<1) | 4 (<1) | 0.02 |
| Bone marrow harvest | 1940 (2) | 282 (1) | 111 (1) | 0.09 |
| Neutropenia | 7357 (9) | 2303 (12) | 1063 (11) | 0.12c |
| No labeled indication observed | 14 000 (16) | 2963 (16) | 1393 (14) | 0.06 |
| Previous filgrastim use | ||||
| None | 84 059 (98) | 14 470 (76) | 7274 (73) | 0.74c |
| Filgrastim originator | 4305 (23) | 2217 (22) | 0.01 | |
| Tbo-filgrastim | 1475 (2) | 277 (3) | 0.07 | |
| Filgrastim-sndz | 479 (1) | 242 (1) | 0.07 | |
| Multiple filgrastim types | 27 (<1) | 66 (<1) | 187 (2) | 0.19c |
Beneficiaries were included if they (1) received a filgrastim injection between January 1, 2014, and December 31, 2016; (2) were continuously enrolled in Medicare Parts A/B fee for service from 6 months prior to administration through 10 days after administration, and (3) did not receive the cohort-defining drug for 6 months prior to filgrastim administration. The first of each type of filgrastim administration satisfying these requirements was selected as the beneficiary’s index administration. These eligibility requirements allow beneficiaries to enter multiple filgrastim product cohorts.
The standardized mean difference (SMD) standardizes comparisons by describing differences in means using units of the pooled standard deviation. A threshold of 0.1 was used to identify larger differences. Only the largest SMDs comparing differences across filgrastim product groups are reported.
SMD >0.1.
Race information is taken from the beneficiary race code variable in the Medicare Beneficiary Summary file.
Region is defined by the US Census Bureau’s census regions.
Beneficiaries can enter Medicare because of end-stage renal disease (ESRD), age (≥65 years), or disability.
Identification of each filgrastim indication was based on the best available definition using Medicare claims data; medical record confirmation for presence of each indication was not included in the study scope.