Characteristics and outcomes of patients defined as adherent users, nonadherent users, and nonadherent nonusers. Values are mean ± SD or n (%).
| Characteristics | Adherence Classification 1: Main Analysis | Adherence Classification 2: Sensitivity Analysis | ||||
|---|---|---|---|---|---|---|
| Adherent User: Timely Anti-TNF Use, n = 135 | Nonadherent User: Late Anti-TNF Use, n = 29 | Nonadherent Nonuser: Unmet Anti-TNF Need, n = 67 | Adherent User: Timely Anti-TNF Use, n = 115 | Nonadherent User: Late Anti-TNF Use, n = 49 | Nonadherent Nonuser: Unmet Anti-TNF Need, n = 67 | |
| Baseline age, yrs | 33.8 ± 9.7 | 33.8 ± 7.5 | 33.7 ± 7.9 | 33.5 ± 10.0 | 34.7 ± 7.8 | 33.7 ± 7.9 |
| Male | 64 (50.0) | 9 (37.5) | 24 (37.5) | 57 (52.8) | 16 (36.4) | 24 (37.5) |
| Postsecondary education | 65 (50.8) | 11 (45.8) | 34 (53.1) | 58 (53.7) | 18 (40.9) | 34 (53.1) |
| Married | 74 (57.8) | 18 (75.0) | 43 (67.2) | 59 (54.6) | 33 (75.0) | 43 (67.2) |
| Academic or executive-level occupation | 18 (14.1) | 4 (16.7) | 11 (17.2) | 16 (14.8) | 6 (13.6) | 11 (17.2) |
| Peripheral arthritis | 90 (70.3) | 17 (70.8) | 35 (54.7) | 73 (67.6) | 34 (77.3) | 35 (54.7) |
| Baseline disease duration | 1.6 ± 0.9 | 1.6 ± 1.0 | 1.5 ± 0.9 | 1.6 ± 0.8 | 1.6 ± 0.9 | 1.5 ± 0.9 |
| Baseline sacroiliitis or spinal inflammation on radiograph, CT, or MRI | 94 (73.4) | 14 (58.3) | 32 (50.0) | 84 (77.8) | 24 (54.5) | 32 (50.0) |
| Baseline CRP | 17.8 ± 21.2 | 10.2 ± 12.0 | 7.0 ± 10.7 | 19.2 ± 22.2 | 9.8 ± 11.2 | 7.0 ± 10.7 |
| Baseline HLA-B27–positive | 97 (75.8) | 20 (83.3) | 47 (73.4) | 81 (75.0) | 36 (81.8) | 47 (73.4) |
| No comorbidities at baseline | 99 (77.3) | 19 (79.2) | 46 (71.9) | 81 (75.0) | 37 (84.1) | 46 (71.9) |
| Mean BASDAI pre-index | 53.6 ± 17.4 | 64.5 ± 10.5 | 58.2 ± 11.0 | 51.3 ± 17.7 | 64.5 ± 10.3 | 58.2 ± 11.0 |
| Mean BASFI pre-index | 39.5 ± 20.8 | 48.6 ± 21.0 | 40.9 ± 21.4 | 37.0 ± 19.8 | 50.0 ± 21.0 | 40.9 ± 21.4 |
| Baseline physician’s assessment of disease activity | 3.4 ± 2.7 | 3.9 ± 2.4 | 5.5 ± 1.3 | 2.8 ± 2.5 | 5.0 ± 2.3 | 5.5 ± 1.3 |
| Nonadherent on physiotherapy recommendations | 48 (37.5) | 12 (50.0) | 21 (32.8) | 42 (38.9) | 18 (40.9) | 21 (32.8) |
| Nonadherent on nonbiologic drug recommendations | 15 (11.7) | 5 (20.8) | 3 (4.7) | 13 (12.0) | 7 (15.9) | 3 (4.7) |
| Nonadherent on specialist care for uveitis | 0 (0) | 1 (4.2) | 0 (0) | 0 (0) | 1 (2.3) | 0 (0) |
| Nonadherent on specialist care for psoriasis | 7 (5.5) | 0 (0) | 2 (3.1) | 7 (6.5) | 0 (0) | 2 (3.1) |
| Nonadherent on specialist care for IBD | 1 (0.8) | 0 (0) | 0 (0) | 1 (0.9) | 0 (0) | 0 (0) |
| Positive response to anti-TNF therapy | 60 (46.9) | 12 (50.0) | NA | 59 (54.6) | 13 (29.5) | NA |
| Time on anti-TNF, mos, 1 yr from index | 10.3 ± 3.3 | 10.0 ± 3.9 | NA | 10.5 ± 3.2 | 9.7 ± 3.7 | NA |
| QALY | 0.586 ± 0.155 | 0.595 ± 0.122 | 0.572 ± 0.135 | 0.604 ± 0.153 | 0.548 ± 0.136 | 0.572 ± 0.135 |
| Total costs | 16,061 ± 7686 | 14,281 ± 8529 | 2092 ± 2880 | 15,408 ± 7433 | 16,692 ± 8730 | 2092 ± 2880 |
| Nonbiologic costs | 3341 ± 4835 | 2350 ± 2607 | 2092 ± 2880 | 2481 ± 3796 | 4913 ± 5742 | 2092 ± 2880 |
| Nonbiologic HR costs | 2014 ± 2384 | 1717 ± 1689 | 1265 ± 1392 | 1739 ± 2127 | 2527 ± 2579 | 1265 ± 1392 |
| Work productivity costs | 1327 ± 4215 | 633 ± 1169 | 827 ± 2234 | 742 ± 3112 | 2385 ± 5232 | 827 ± 2234 |
Anti-TNF: antitumor necrosis factor; CT: computed tomography; MRI: magnetic resonance imaging; CRP: C-reactive protein; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; BASFI: Bath Ankylosing Spondylitis Functional Index; IBD: inflammatory bowel disease; QALY: quality-adjusted life-years; HR: health resource; NA: not applicable.