Figures
- FIGURE 1
Frequency histogram of the distribution of Pittsburgh Sleep Quality Index (PSQI) for 101 patients. Green shaded columns represent normal PSQI (i.e. ≤5 units), black columns represent increased PSQI (>5 units).
Tables
- TABLE 1
Baseline characteristics of patients with interstitial lung disease
Variable Poor sleep quality (PSQI>5) Good sleep quality (PSQI≤5) p-value Subjects n 67 34 Age years 68.3±10.4 71.6±10.3 0.13 Males n (%) 35 (54%) 21 (62%) 0.52 BMI kg·m−2 28.1 (25.2–32.9) 27.9 (23.8–32.5) 0.57 FEV1 % pred 65.1±19.2 68.7±20.4 0.40 FVC % pred 63.3±18.8 65.9±20.5 0.54 STOP-Bang au 4.0±1.6 3.6±1.4 0.19 ESS au 7 (4–8) 4 (2–7) 0.003 Neck circumference cm 39.7±4.8 39.3±3.7 0.75 mMRC au 2.3±1.1 1.9±1.0 0.08 SGRQ-Symptoms 57.2±20.7 39.4±19.2 <0.0001 SGRQ-Activities 75.8±19.4 66.7±19.0 0.03 SGRQ-Impacts 48.0±20.2 35.7±19.7 0.005 SGRQ-Total au 58.0±16.0 46.1±16.8 0.001 HADS-Anxiety au 7.1±4.6 4.4±3.4 0.004 0–7 n/N (%) 37/65 (57%) 28/34 (82%) 8–21 n/N (%) 28/65 (43%) 6/34 (18%) HADS-Depression au 6.8±3.8 4.4±3.9 0.004 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.
- TABLE 2
Sleep latency, sleep duration and Pittsburgh Sleep Quality Index (PSQI) component score data obtained from PSQI questionnaire
Variable Poor sleep quality (PSQI>5) Good sleep quality (PSQI≤5) p-value Sleep latency min 30 (15–45) 10 (5–15) <0.0001 Sleep duration h 6 (5–7) 8 (7–9) <0.0001 PSQI global score au 9.8±2.9 3.5±1.2 PSQI component scores# Sleep quality 1.43±0.66 0.68±0.64 <0.0001 Sleep latency 1.77±0.90 0.44±0.61 <0.0001 Sleep duration 1.25±1.05 0.12±0.41 <0.0001 Habitual sleep efficiency 1.68±1.09 0.15±0.36 <0.0001 Sleep disturbance 1.97±0.69 1.38±0.55 <0.0001 Use of sleep medications 0.62±1.14 0.03±0.17 0.004 Daytime dysfunction 1.25±0.79 0.71±0.72 0.001 Data are presented as mean±sd or median (interquartile range), unless stated otherwise. au: arbitrary units. #: Each component score ranges from 0 (no difficulty) to 3 (severe difficulty) on a Likert scale.
- TABLE 3
Individual questions for component 5 (sleep disturbance) in the Pittsburgh Sleep Quality Index (PSQI) questionnaire
Variable Poor sleep quality (PSQI>5) Good sleep quality (PSQI≤5) p-value Cannot get to sleep within 30 min 2 (1–3) 0 (0–1) <0.0001 Wake up in the middle of the night or early morning 3 (2–3) 2 (0–3) 0.002 Have to get up to use the bathroom 3 (2–3) 3 (2–3) 0.45 Cannot breathe comfortably 2 (0–3) 0 (0–2) 0.02 Cough or snore loudly 3 (1–3) 1 (0–3) 0.07 Feel too cold 1 (0–3) 1 (0–1.25) 0.02 Feel too hot 1 (0–2.5) 0 (0–0.25) 0.0004 Have bad dreams 1 (0–3) 0 (0–0) 0.14 Have pain 1 (0–3) 0 (0–2) 0.006 Other reasons 1 (0–3) 0 (0–1) 0.001 Data presented as median (interquartile range), unless stated otherwise. Scores are as follows. 0: not during the past month; 1: less than once a week; 2: one or twice a week; 3: three or more times a week.
- TABLE 4
Final model from multivariable logistic regression
Adjusted odds ratio#
(95% CI)Wald χ2 DF p-value HADS-Depression score 0 to 2 1.0¶ 13.78 3 0.003 3 to 4 2.59 (0.69–9.75) 5 to 8 10.05 (2.5–40.0) ≥9 8.91 (2.1–37.8) ESS score 0 to 2 1.0¶ 8.90 3 0.03 3 to 5 1.19 (0.33–4.25) 6 to 8 5.64 (1.2–26.5) ≥8 4.47 (1.2–16.5) HADS: Hospital Anxiety and Depression Scale; ESS: Epworth Sleepiness Scale; DF: degrees of freedom. #: adjusted for HADS-D and ESS; ¶: reference category.
Supplementary Material
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Supplementary tables 1 and 2 00062-2019_Supplementary_material
