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Table 1 Baseline characteristics by FVC% change group

From: Change in forced vital capacity and associated subsequent outcomes in patients with newly diagnosed idiopathic pulmonary fibrosis

  By lung-function change category (based on relative change in FVC%)a
  Stable [A] Marginal [B] Significant [C] P-value*
  (N = 250) (N = 98) (N = 142) [C] vs. [A] [C] vs. [B] [B] vs. [A]
Male, N (%) 167 (66.8 %) 70 (71.4 %) 98 (69.0 %) 0.999 0.999 0.999
Age (years), mean (SD) 60.8 (10.8) 62.1 (9.6) 60.9 (11.5) 0.999 0.999 0.930
BMI, mean (SD) 26.7 (4.9) 26.5 (4.4) 26.3 (4.6) 0.999 0.999 0.999
Race, N (%)b
 White 183 (73.2 %) 82 (83.7 %) 104 (73.2 %) 0.999 0.193 0.098
 Black or African American 34 (13.6 %) 11 (11.2 %) 24 (16.9 %) 0.999 0.650 0.999
 Hispanic, Latino, or Spanish Origin 26 (10.4 %) 5 (5.1 %) 13 (9.2 %) 0.999 0.646 0.295
 Asian 7 (2.8 %) 1 (1.0 %) 1 (0.7 %) 0.479 0.999 0.952
 Other 2 (0.8 %) 0 (0.0 %) 0 (0.0 %)    
Insurance type, N (%)b
 Commercial/private insurance 113 (45.2 %) 45 (45.9 %) 80 (56.3 %) 0.193 0.502 0.999
 Medicare 109 (43.6 %) 44 (44.9 %) 61 (43.0 %) 0.999 0.999 0.999
 Medicaid 26 (10.4 %) 12 (12.2 %) 17 (12.0 %) 0.999 0.999 0.999
 Military insurance (VA or active military) 9 (3.6 %) 2 (2.0 %) 3 (2.1 %) 0.999 0.999 0.999
 Other 0 (0.0 %) 1 (1.0 %) 0 (0.0 %) - - -
 No insurance 8 (3.2 %) 1 (1.0 %) 1 (0.7 %) 0.228 0.999 0.584
Smoking status at diagnosis, N (%)     0.789 0.999 0.999
 Never smoked 98 (39.2 %) 44 (44.9 %) 48 (33.8 %)    
 Former smoker 124 (49.6 %) 42 (42.9 %) 77 (54.2 %)    
 Current smoker 21 (8.4 %) 11 (11.2 %) 16 (11.3 %)    
 Unknown/not sure 7 (2.8 %) 1 (1.0 %) 1 (0.7 %)    
Exposure to activities/ environmental agents, N (%)b
 Asbestos 10 (4.0 %) 3 (3.1 %) 11 (7.7 %) 0.336 0.650 0.999
 Farming/agriculture 27 (10.8 %) 9 (9.2 %) 25 (17.6 %) 0.213 0.131 0.999
 Hairdressing 12 (4.8 %) 4 (4.1 %) 4 (2.8 %) 0.999 0.999 0.999
 Metal dust 18 (7.2 %) 2 (2.0 %) 10 (7.0 %) 0.999 0.172 0.154
 Stone cutting/polishing 7 (2.8 %) 0 (0.0 %) 6 (4.2 %) 0.999 <0.001* <0.001*
 Coal mining 5 (2.0 %) 1 (1.0 %) 2 (1.4 %) 0.999 0.999 0.999
 Other 3 (1.2 %) 3 (3.1 %) 2 (1.4 %) 0.999 0.999 0.669
 None 182 (72.8 %) 78 (79.6 %) 92 (64.8 %) 0.340 0.037* 0.598
Family history of pulmonary fibrosis, N (%) 16 (6.4 %) 6 (6.1 %) 5 (3.5 %) 0.564 0.923 0.999
Measurement period (days)
 Concurrent, mean (SD) 172.8 (55.5) 174.9 (53.7) 181.6 (56.8) 0.575 0.999 0.999
 Subsequent, mean (SD) 438.3 (283.1) 423.0 (280.0) 340.1 (275.9) 0.013* 0.118 0.999
 Total follow-up, mean (SD) 611.1 (282.7) 597.9 (285.8) 521.7 (286.6) 0.036* 0.225 0.999
  1. aLung-function change categories were defined as the relative change in FVC% from index to approximately 6 months following IPF diagnosis. "Stable" was defined as decline <5 %. "Marginal" was defined as decline ≥5 % and <10 %, while "Significant" was defined as decline ≥10 %
  2. bPhysicians were allowed to select multiple values for race, insurance type, and exposure to activities/environmental agents, so counts and percentages may not sum to the total N or 100 %
  3. *All p-values were adjusted for multiple comparisons using the Bonferroni correction