TABLE 1

Baseline characteristics of patients with interstitial lung disease

VariablePoor sleep quality (PSQI>5)Good sleep quality (PSQI≤5)p-value
Subjects n6734
Age years68.3±10.471.6±10.30.13
Males n (%)35 (54%)21 (62%)0.52
BMI kg·m−228.1 (25.2–32.9)27.9 (23.8–32.5)0.57
FEV1 % pred65.1±19.268.7±20.40.40
FVC % pred63.3±18.865.9±20.50.54
STOP-Bang au4.0±1.63.6±1.40.19
ESS au7 (4–8)4 (2–7)0.003
Neck circumference cm39.7±4.839.3±3.70.75
mMRC au2.3±1.11.9±1.00.08
SGRQ-Symptoms57.2±20.739.4±19.2<0.0001
SGRQ-Activities75.8±19.466.7±19.00.03
SGRQ-Impacts48.0±20.235.7±19.70.005
SGRQ-Total au58.0±16.046.1±16.80.001
HADS-Anxiety au7.1±4.64.4±3.40.004
 0–7 n/N (%)37/65 (57%)28/34 (82%)
 8–21 n/N (%)28/65 (43%)6/34 (18%)
HADS-Depression au6.8±3.84.4±3.90.004
 0–7 n/N (%)37/65 (57%)29/34 (85%)
 8–21 n/N (%)28/65 (43%)5/34 (15%)

Data are presented as mean±sd or median (interquartile range), unless stated otherwise. PSQI: Pittsburgh Sleep Quality Index; BMI: body mass index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; ESS: Epworth Sleepiness Scale; mMRC: modified Medical Research Council Dyspnoea Scale; SGRQ: St George's Respiratory Questionnaire; HADS: Hospital Anxiety and Depression Scale (0–7=normal, 8–10=borderline abnormal, 11–21=abnormal); au: arbitrary units.