Table 2 Associations between IRT-derived disability scores and prevalence of unemployment after adjustment for patient characteristics
Characteristic | Bifactor model | Unidimensional model | ||
|---|---|---|---|---|
N (%) | PRa(95% CI) | PRa(95% CI) | PRa(95% CI) | |
Global disability (scaled score, S)b | ||||
S ≤ 33.3 | 562 (14.3) | 1.0c,d | 1.0c,d | 1.0c,e |
33.3 < S ≤ 50 | 1390 (35.4) | 1.50 (1.28, 1.77) | 1.83 (1.55, 2.17) | 1.73 (1.46, 2.04) |
50 < S ≤ 66.7 | 1428 (36.4) | 2.14 (1.83, 2.51) | 2.75 (2.34, 3.23) | 2.87 (2.46, 3.36) |
S > 66.7 | 546 (13.9) | 2.74 (2.33, 3.22) | 3.66 (3.12, 4.30) | 3.79 (3.24, 4.43) |
Residual physical disability (scaled score, S)b | ||||
S ≤ 33.3 | 257 (6.5) | 1.0c,d | ||
33.3 < S ≤ 50 | 1876 (47.8) | 1.17 (.99, 1.38) | ||
50 < S ≤ 66.7 | 1339 (34.1) | 1.56 (1.32, 1.84) | ||
S > 66.7 | 454 (11.6) | 2.02 (1.70, 2.40) | ||
Residual mental disability (scaled score, S)b | ||||
S ≤ 33.3 | 236 (6.0) | 1.0c,d | ||
33.3 < S ≤ 50 | 1678 (42.7) | 1.11 (.98, 1.26) | ||
50 < S ≤ 66.7 | 1783 (45.5) | 1.35 (1.19, 1.52) | ||
S > 66.7 | 229 (5.8) | 1.53 (1.32, 1.78) | ||
Disease duration (y.) | ||||
≤ 10 | 1713 (43.6) | 1.0c | 1.0c | 1.0c |
11 – 20 | 1109 (28.3) | 1.06 (.98, 1.14) | 1.10 (1.02, 1.19) | 1.09 (1.01, 1.18) |
≥ 21 | 1104 (28.1) | 1.21 (1.13, 1.30) | 1.27 (1.18, 1.37) | 1.25 (1.16, 1.34) |
Age at assessment (y.) | ||||
≤ 35 | 749 (19.1) | 1.0c | 1.0c | 1.0c |
36 – 55 | 1760 (44.8) | 1.01 (.91, 1.11) | 1.03 (.93, 1.14) | 1.02 (.92, 1.13) |
≥ 56 | 1417 (36.1) | 1.22 (1.10, 1.35) | 1.31 (1.18, 1.45) | 1.28 (1.16, 1.42) |
Gender | ||||
Female | 3102 (79.4) | 1.0c | 1.0c | 1.0c |
Male | 803 (20.6) | 1.04 (.98, 1.10) | 1.08 (1.02, 1.15) | 1.08 (1.01, 1.14) |
Race/Ethnicity | ||||
White | 3491 (90.2) | 1.0c | 1.0c | 1.0c |
African American | 132 (3.4) | 1.14 (.99, 1.31) | 1.16 (1.00, 1.33) | 1.14 (.99, 1.31) |
Hispanic/Latino | 120 (3.1) | 1.14 (.97, 1.34) | 1.11 (.95, 1.31) | 1.12 (.94, 1.31) |
Native American | 76 (2.0) | 1.11 (.95, 1.30) | 1.10 (.95, 1.28) | 1.09 (.94, 1.25) |
Other | 49 (1.3) | 1.23 (1.00, 1.52) | 1.24 (1.00, 1.52) | 1.16 (.94, 1.43) |
Disease modifying therapy | ||||
Yes | 2614 (66.6) | 1.0c | 1.0c | 1.0c |
No | 1312 (33.4) | 1.05 (.99, 1.11) | 1.08 (1.02, 1.14) | 1.06 (1.01, 1.13) |
Year of assessment | ||||
2003-2005 | 1640 (41.8) | 1.0c | 1.0c | 1.0c |
2006-2008 | 957 (24.4) | 1.01 (.94, 1.08) | 1.01 (.94, 1.09) | 1.02 (.95, 1.09) |
2009-2011 | 1329 (33.8) | 1.04 (.98, 1.11) | 1.01 (.94, 1.07) | 1.01 (.95, 1.08) |