Fig. 3

SGRQ-I total score in (a) the lower and upper quartile of FVC % predicted, (b) the lower and upper quartile of DLCO % predicted, (c) long-term oxygen therapy and (d) GAP index. The midlines in the boxes are the median values and the boundaries are the 25th and 75th percentiles; the whiskers are the upper adjacent values (1.5 interquartile range above the 75th percentile) and lower adjacent values (1.5 interquartile range below the 25th percentile). The dots are outlying values. SGRQ-I: IPF-specific version of the St. George’s Respiratory Questionnaire. FVC: Forced vital capacity; DLCO: Diffusing capacity of the lung for carbon monoxide; LTOT: Long-term oxygen therapy; GAP: Gender, age, physiology