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Table 2 Clinical characteristics at initial IPF diagnosis 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. [A] [C] vs. [A]
Comorbidities, N (%)b       
 Gastroesophageal reflux disease 82 (32.8 %) 26 (26.5 %) 45 (31.7 %) 0.999 0.999 0.999
 Cardiac disorder 43 (17.2 %) 28 (28.6 %) 34 (23.9 %) 0.260 0.999 0.053
 Metabolic disorder 38 (15.2 %) 20 (20.4 %) 29 (20.4 %) 0.500 0.999 0.642
 Other vascular disorder 32 (12.8 %) 23 (23.5 %) 27 (19.0 %) 0.300 0.999 0.069
 Pulmonary hypertension 31 (12.4 %) 20 (20.4 %) 16 (11.3 %) 0.999 0.095 0.198
 Emphysema 18 (7.2 %) 8 (8.2 %) 15 (10.6 %) 0.783 0.999 0.999
 Other pulmonary disorder 14 (5.6 %) 7 (7.1 %) 13 (9.2 %) 0.435 0.999 0.999
Symptoms at IPF diagnosis, N (%)b
 Dyspnea/shortness of breath 209 (83.6 %) 88 (89.8 %) 132 (93.0 %) 0.030* 0.999 0.668
 Cough 175 (70.0 %) 71 (72.4 %) 110 (77.5 %) 0.428 0.999 0.999
 Fatigue or malaise 107 (42.8 %) 47 (48.0 %) 78 (54.9 %) 0.145 0.999 0.999
 Rapid, shallow breathing 25 (10.0 %) 11 (11.2 %) 14 (9.9 %) 0.999 0.999 0.999
 Gradual, unintended weight loss 17 (6.8 %) 9 (9.2 %) 24 (16.9 %) 0.035* 0.317 0.999
 Clubbing 14 (5.6 %) 11 (11.2 %) 17 (12.0 %) 0.309 0.999 0.321
 Other 1 (0.4 %) 0 (0.0 %) 2 (1.4 %) - - -
GAP index, mean (SD)c 3.3 (1.5) 3.5 (1.5) 3.7 (1.4) 0.149 0.999 0.774
Lung-function measures at IPF diagnosis, mean [median] (SD)
 FVC (liters) 2.6 (1.1) 2.4 (0.9) 2.4 (1.0) 0.821 0.999 0.796
 FVC% 61.7 %(26.1 %) 58.5 % (24.0 %) 59.5 % (27.6 %) 0.999 0.999 0.999
 FEV1 (liters) 2.0 (0.9) 1.8 (0.7) 1.7 (0.6) 0.021* 0.901 0.395
 FEV1/FVC 79.6 % (12.6 %) 79.9 % (11.8 %) 80.7 % (12.5 %) 0.999 0.999 0.999
 DLCO percent predicted 53.4 % (14.4 %) 51.2 % (16.1 %) 47.7 % (16.5 %) 0.033* 0.583 0.962
  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 comorbidities and symptoms, so counts and percentages may not sum to the total N or 100 %
  3. cMissing values for DLCO were imputed using a single imputation method in which observed DLCO was regressed on patient's index FVC%, age, gender, BMI, smoking status at diagnosis, exposure to environmental agents, comorbidities (including cardiac disorder, pulmonary hypertension, emphysema, and gastroesophageal reflux disease), and symptoms at IPF diagnosis (including dyspnea/shortness of breath and gradual, unintended weight loss)
  4. *All p-values were adjusted for multiple comparisons using the Bonferroni correction