CLINICAL
Table 1 Sociodemographic Characteristics TNF-alpha blocker nonusers Mild RA Moderate RA Severe RA
Variable 720 (62.50) 159 (13.81) 208 (18.05) Sample size, N (%) 59.0 (0.83) 60.5 (1.65) 58.6 (0.95) Age (mean SE) 205 (29.11) 41 (27.23) 45 (24.20) Sex, N (% male) Race 578 (85.05) 126 (86.55) 160 (81.58) White, N (%) 106 (10.22) 27 (11.06) 30 (9.61) Black, N (%) 86 (7.16) 31 (9.88) 27 (6.52) Hispanic, N (%) 10 (1.06) 3 (0.73) 4 (1.11) American Indian, N (%) 26 (3.67) 3 (1.66) 14 (7.70) Other, N (%) Region 286 (37.12) 67 (35.72) 90 (38.43) South, N (%) 159 (24.03) 33 (22.39) 52 (28.72) Midwest, N (%) 167 (21.79) 42 (31.31) 48 (21.42) West, N (%) 108 (16.99) 17 (10.58) 18 (11.44) Northeast, N (%) Education 134 (13.97) 63 (33.42) 71 (28.60) No degree, N (%) 430 (64.19) 76 (53.83) 110 (57.71) Completed high school, N (%) 83 (12.62) 13 (8.70) 8 (3.73) Bachelor’s degree, N (%) 23 (3.28) 1 (0.45) 3 (1.30) MA/PhD, N (%) 48 (5.94) 6 (3.60) 16 (8.70) Other degree, N (%) Income 95 (10.73) 55 (28.09) 70 (27.01) Poor, N (%) 45 (4.68) 17 (12.76) 24 (10.75) Near poor, N (%) 117 (14.77) 31 (21.30) 35 (15.10) Low income, N (%) 236 (35.20) 43 (27.32) 54 (30.80) Medium income, N (%) 227 (34.62) 13 (10.52) 25 (16.32) High income, N (%) Insurance status 461 (68.44) 61 (47.36) 66 (37.32) Private insurance, N (%) 203 (25.21) 82 (44.15) 125 (54.98) Public insurance, N (%) 56 (6.34) 16 (8.48) 17 (7.69) Uninsured, N (%) RA indicates rheumatoid arthritis; SE, standard error; TNF, tumor necrosis factor. or severe RA) on healthcare utilization outcomes and missed workdays. A generalized linear model with log link and gamma distribution was used to estimate the impact of the type of RA group on healthcare expenditures. The Heckman selection model, which is a 2-stage model that is used to estimate the costs for populations that may include individuals with zero costs as well, was used to estimate the impact of the type of RA group on
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TNF-alpha blocker users 65 (5.6) 55.9 (2.14) 17 (28.03) 55 (90.85) 8 (5.87) 7 (5.30) 0 (0.00) 2 (3.28) 20 (20.55) 18 (30.19) 17 (31.48) 10 (17.79) 10 (12.86) 35 (56.93) 15 (22.81) 2 (4.22) 3 (3.17) 11 (13.96) 3 (2.15) 7 (13.12) 19 (28.50) 25 (42.27) 45 (71.29) 19 (27.95) 1 (0.75)
the annual wage. These outcome variables were regressed using the type of RA group (ie, “mild RA” as the reference group), controlling for age, sex, race, ethnicity, region of residence, education, income, type of insurance coverage, and comorbidity. To estimate wages and employment, income was excluded from the models. All analyses were conducted with STATA version 11 (Stata Corporation, College Station, TX).
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March/April 2013
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Vol 6, No 2