Table 4.
Summary of studies that used the Epworth Sleepiness Scale
| Reference | Study focus | COPD study sample | Measures of COPD severity | ESS (mean ± SD/median and range) | ESS >10 (%) | Associations with ESS score |
|---|---|---|---|---|---|---|
| Aras et al36 | RLS symptoms in COPD patients during an exacerbation period | 22 male inpatients | GOLD stage IV: FEV1 30% or 50% plus chronic respiratory failure; mean FEV1 39.4%±9.97% | Not reported | Not reported | Free thyroxine values negatively correlated with ESS (rs =−0.481 P=0.043) |
| Bednarek et al46 | Prevalence of SDB and COPD in a representative urban sample aged 41–72 years | 676 participants from the electoral register | FEV1/FEV <0.7, 10.6% | 6.4±3.9 | Not reported | Mean ESS in people with excessive sleep disorder: men 12.6±2.0 versus women 12.9±2.4 (P>0.05) |
| Budhiraja et al11 | Prevalence of insomnia in patients with COPD, and characteristics associated with insomnia in COPD patients | 183 hospital patients | GOLD stage I, 3%; stage II, 39%; stage III, 29%; stage IV, 28%; % predicted post-bronchodilator FEV 45.9±18.6. FEV1/FVC ratio 49.6±12.5 | Not reported | Not reported | Daytime sleepiness (ESS >10) greater in patients with insomnia (36.5% versus 14.6%, P=0.004) |
| Cavalcante et al35 | Occurrence and associations with RLS in a COPD population | 104 hospital outpatient attenders | mMRC 0 (4.8%); 1 and 2 (48.1%); 3 (34.6%); 4 (12.5%) | 6.9±5.1 | 20.2 | No difference in mean values between patients without RLS (6.6±4) versus with RLS (7.7±6.0). ESS positively correlated with BMI (P<0.003) |
| De Lima et al47 | Whether clinically stable COPD patients without cognitive symptoms may present with subtle cognitive impairments | 30 hospital outpatients | Mean FEV1 42.1±15.9 | 6.7±3.7 | Not reported | Not reported |
| Kapella et al39 | Feasibility and assessment of the impact of a CBT intervention for people with COPD and insomnia | 23 patients recruited from advertisements and word of mouth | FEV1/FVC ratio <70% 1 | 9.2±5.0 | Not reported | Not reported |
| Karachaliou et al32 | Association between OSAHS-related symptoms and physician-diagnosed asthma and COPD | 1,501 primary care patients (323 with COPD) | GOLD stage I, 28.8%; stage II, 53.3%; stage III, 15.2%; stage IV, 2.8% | Not reported | Not reported | Increased odds of people with COPD having an ESS score ≥10; OR 2.04, 95% CI (1.33–3.14) |
| Lewis et al48 | Variability of nocturnal desaturation in COPD over a 3-week period and impact the variability may have on clinical decision-making | 26 stable COPD hospital outpatients | Mean post-bronchodilator FEV1 28.6% | 4.1±6.2; range 0–11 | Not reported | Not reported |
| Lewis et al49 | Prevalence and clinical impact of nocturnal desaturation in a typical outpatient population with COPD | 59 COPD outpatients | Mean predicted FEV1 37.2±14.9; FVC 1.9 ±0.9; FVC predicted 62.1±17.6; TB90% 38.4±34.9 | 5.0; range 2.0–8.0 | Not reported | No significant difference between desaturators and nondesaturators (P=0.88) |
| Lo Coco et al33 | Prevalence, severity, and associations with RLS in COPD patients | 87 COPD outpatients | GOLD stage II, 42.5%; stage III, 40.2%; stage IV, 17.3% | 8.98±3.89 | Not reported | Significant difference in mean ESS score between COPD with RLS and controls with RLS 11.81±1.09 versus 8.62±3.66 (P=0.009) |
| McNicholas et al50 | Placebo-controlled, double-blind trial of severe, stable COPD patients comparing the effect of tiotropium on sleeping oxygen saturation | 56 hospital outpatients | FEV1 <65% predicted; FEV1/FVC <70%; Awake paO2 <9.98 kPa (75 mmHg) prior to entry | 5.7 in intervention group versus 6.4 in control group | Not reported | None reported |
| Nunes et al51 | Sleep quality in COPD patients at home using actigraphy and association between sleep quality and daytime somnolence | 26 hospital patients | GOLD stage II, 50%; stage III, 3 8.5%; stage IV, 11.5%; FEV1% predicted 47.62±16.04 | 8.27±4.4 | 61.5 | No difference between COPD and controls (8.27±4.4 versus 6.07±3.9, P=0.12). No difference in proportion with ESS ≥10 COPD (61% versus controls 86%; P=0.09) |
| Oliveira et al52 | Evaluate accuracy of a portable monitoring device in detection of OSA in patients with COPD | 26 hospital outpatients | FEV1/FVC 0.6±0.10; FEV1 (%) post-BD 55±0.08; FVC (%) post-BD 77±8.9 | 10.5±4.1 | Not reported | None reported |
| Scharf et al53 | Correlation between disturbed sleep and COPD | 180 pulmonary clinic patients | GOLD stage I, 10.6%; stage II, 3 0.6%; stage III, 46.1%; stage IV, 12.8%. FEV1 % predicted 47.6±15.2 | 7.0±4.8 | 24.7 | No associations with ESS and other symptoms |
| Soriano et al54 | Natural history of the most common respiratory chronic conditions, including COPD and OSA | 500 primary care patients | GOLD stage I (27%); stage II (58%); stage III (15%) | Not reported | 29.2 | None reported |
| Stege et al34 | Effects of long-term use of a benzodiazepine (temazepam) on breathing, dyspnea, and gas exchange during sleep, sleep quality, and sleepiness | 14 respiratory clinic patients | FEV1 % predicted 33.5±9.2; FEV1/FVC% 32.7±13.0; FEV1 (L) 0.99 ±0.30 | 6.0±4.0 | 50.0 | No difference between temazepam (5.0±4.0) and controls (6.0±4.0; P=0.13) |
| Toraldo et al55 | Pattern of daytime clinical variables that distinguish desaturator patients from nondesaturator COPD patients using cluster analysis | 51 consecutive hospital patients | FEV1 % predicted 53 (SE 1.5); FEV1/FVC ratio 37.6 (SE 0.5); FVC % predicted 81.5 (SE 1.2); AHI 2.8 (SE 0.1). Daytime paO2 values 60–70 mmHg |
3.9 (SE ±0.1) | None | No difference between desaturators and nondesaturators, both 3.8 (± SE 0.4) |
| Toraldo et al56 | Effect of regular use of nCPAP in patients with overlap syndrome | 12 hospital outpatients | FEV1 (%) 60.3±1.3; FEV1/FVC (%) 69.5±0.7 | 16.58±0.86 | Not reported | Reductions in ESS score between baseline and 3 months (16.6±0.86 versus 11.7±0.46; P=0.0001); 3 months and 12 months (11.7±0.46 versus 5.7±0.4; P=0.0001), and 12 and 24 months (5.67±0.4 versus 4.75±0.49; P=0.033) |
| Trauer et al57 | Relationship between 24-hour oximetry and resting partial pressure of oxygen | 35 community-living patients | GOLD stage II, 20%; stage III, 4 9%; and stage IV, 31%; FEV1 % predicted 37.5±13.2 | Median 4 (IQR 2, 8) | Not reported | Negative correlation between ESS and time below 90% SpO2 −24 hours −0.18 (0.29); waking hours −0.13 (0.46); sleeping hours −0.17 (0.24) |
| Tsolaki et al58 | Effect of non-invasive ventilation as an additional treatment for severe COPD patients | 24 hospital outpatients | FEV1 (%) 34.7±11.3; FVC (%) 50.8±15.7 | 9.2±3.7 | Not reported | Significant reductions in ESS score between baseline and 1 month in patients who received noninvasive ventilation (10.3 versus 4.9; P=0.0001). ESS was an independent predictor of the Mental Component Score of the SF-36 (P<0.001) |
Abbreviations: AHI, apnea-hypopnea index; BD, bronchodilator; BMI, body mass index; CI, confidence interval; OR, odds ratio; COPD, chronic obstructive pulmonary disease; RLS, restless legs syndrome; SDB, sleep-disordered breathing; CBT, cognitive behavioral therapy; OSAHS, obstructive sleep apnea/hypopnea syndrome; mMRC, modified Medical Research Council Dyspnoea scale; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second; GOLD, Global initiative for chronic Obstructive Lung Disease; SpO2, oxygen saturation; ESS, Epworth Sleepiness Scale; SE, standard error; pO2, oxygen partial pressure; paO2, arterial oxygen tension; IQR, interquartile range; TB90%, time spent with saturation below 90%; SF-36, Short-Form 36 Health Survey; nCPAP, nasal continuous positive airway pressure; SD, standard deviation; OSA, obstructive sleep apnea.