Table 2

Baseline mean (SD) physiologic and quality-of-life measurements in four subgroups based on disease severity at the time of diagnosis and the length of total diagnostic delay

Moderate-to-severe disease at diagnosis (FVC≤80% predicted)Mild disease at diagnosis (FVC>80% predicted)
Diagnostic delay<1 year (N=29)Diagnostic delay>1 year (N=58)P valueDiagnostic delay<1 year (N=47)Diagnostic delay>1 year (N=126)P value
FVC (% predicted)69.55 (7.17)68.34 (9.11)0.53104.43 (16.46)98.19 (12.82)<0.01
DLCO (% predicted)47.19 (11.10)51.12 (14.59)0.2254.40 (14.50)52.86 (12.67)0.50
6MWT distance (m)425.40 (116.53)434.68 (107.12)0.73433.48 (119.36)447.59 (102.86)0.47
SpO2 after 6MWT*83.88 (11.67)86.81 (6.80)0.1790.60 (5.41)89.04 (6.38)0.16
SGRQ, total score53.22 (16.72)51.72 (17.62)0.8040.91 (14.63)49.33 (17.65)0.03
SGRQ-Ider, total score50.29 (18.34)47.01 (21.99)0.6334.37 (19.97)45.41 (22.26)0.02
CAT, total score16.78 (6.46)17.02 (7.14)0.8814.07 (7.46)16.08 (6.75)0.11
CAT, dyspnoea score3.75 (1.46)3.68 (1.26)0.832.72 (1.69)3.35 (1.43)0.02
CAT, cough score2.79 (1.29)2.42 (1.12)0.182.26 (1.31)2.42 (1.24)0.48
  • P values based on univariate analysis.

  • *On room air.

  • CAT, COPD assessment test; DLCO, diffusing capacity for carbon monoxide; FVC, forced vital capacity; 6MWT, six min walk test; SGRQ, St. George’s Respiratory Questionnaire; SGRQ-Ider, IPF-specific SGRQ, derived from the original SGRQ; SpO2, peripheral capillary oxygen saturation.