Table 2.
Baseline HCRU and costs in the matched cohorts (subset with complete pharmacy cost capture)
| HCRU and costs | Synthroid persistent users (n = 14,140) |
Generic levothyroxine persistent users (n = 15,891) |
Standardized differencea |
|---|---|---|---|
| n (%)/mean (SD) | n (%)/mean (SD) | ||
| All-cause HCRU | |||
| Inpatient hospitalizations, n (%) | 826 (5.8) | 918 (5.8) | 0.003 |
| ED visits, n (%) | 1088 (7.7) | 1181 (7.4) | 0.010 |
| Outpatient services, n (%) | 13,942 (98.6) | 15,661 (98.6) | 0.004 |
| Pharmacy fills, n (%) | 13,354 (94.4) | 15,187 (95.6) | –0.052 |
| Fills per patient, mean (SD) | 9.2 (7.45) | 9.3 (7.58) | –0.020 |
| Hypothyroidism-related HCRUb | |||
| Inpatient hospitalizations, n (%) | 456 (3.2) | 503 (3.2) | 0.003 |
| ED visits, n (%) | 299 (2.1) | 240 (1.5) | 0.045 |
| Outpatient services, n (%) | 11,511 (81.4) | 13,072 (82.3) | –0.022 |
| Pharmacy fills, n (%) | 9325 (65.9) | 10,779 (67.8) | –0.040 |
| Fills per patient, mean (SD) | 2.3 (2.27) | 2.2 (2.18) | 0.032 |
| All-cause healthcare costs, per patient in 2017 USD | |||
| Inpatient hospitalizations, mean (SD) | 1288 (9910) | 1695 (16,956) | –0.029 |
| ED visits, mean (SD) | 162 (863) | 165 (984) | –0.003 |
| Outpatient services, mean (SD) [median] | 2861 (6395) [1099] | 2668 (5754) [1024] | 0.032 |
| Pharmacy fills, mean (SD) [median] | 1478 (3618) [613] | 1448 (3332) [585] | 0.008 |
| Total medical costsc, mean (SD) [median] | 4311 (12,585) [1,215] | 4528 (18,492) [1,121] | –0.014 |
| Total costsd, mean (SD) [median] | 5788 (13,534) [2346] | 5976 (19,143) [2211] | –0.011 |
| Hypothyroidism-related costsb, per patient in 2017 USD | |||
| Inpatient hospitalizations, mean (SD) | 631 (5061) | 786 (8722) | –0.022 |
| ED visits, mean (SD) | 49 (539) | 34 (501) | 0.029 |
| Outpatient services, mean (SD) [median] | 291 (1352) [102] | 277 (1166) [100] | 0.011 |
| Pharmacy fills, mean (SD) [median] | 77 (76) [67] | 35 (41) [25] | 0.697 |
| Total medical costsc, mean (SD) [median] | 971 (5271) [114] | 1097 (8820) [109] | –0.017 |
| Total costsd, mean (SD) [median] | 1049 (5272) [211] | 1132 (8819) [148] | –0.011 |
ED emergency department, HCRU healthcare resource utilization, SD standard deviation, USD US Dollars
aStandardized difference = difference in means or proportions divided by the pooled standard deviation. An absolute value of the standardized difference < 0.1 was used to indicate balance in a variable across the cohorts
bHypothyroidism-related healthcare utilization and cost were based on medical claims with an ICD-9-CM diagnosis code of (244.0x, 244.1x, 244.8x, or 244.9x) or ICD-10-CM diagnosis code of (E01.8%, E03.8%, E89.0%, or E03.9%) and pharmacy claims for hypothyroidism medications (including levothyroxine, liothyronine, desiccated thyroid, liotrix, and thyroglobulin)
cTotal medical costs included inpatient, ED, and outpatient costs
dTotal costs were the sum of medical and pharmacy costs