Relationships Between the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Clinical/Polysomnographic Measures in a Community Sample

Abstract

S leep quality and daytime sleepiness are salient and clinically relevant dimensions of sleep-wake function. Poor sleep quality and insomnia symptoms have been associated with worse health, increased health care costs and utilization, absenteeism from work, and increased risk for psychiatric disorders, including depression. 1 Daytime sleepiness has been associated with increased risk of motor vehicle accidents, worse physical health, and increased mortality risk. 2 Although sleep and sleepiness can be measured by objective means such as polysomnography (PSG) and the multiple sleep latency test (MSLT), these methods are often impractical as clinical screening or research tools. Self-report questionnaires are most commonly used to assess sleep quality and daytime sleepiness. Many different instruments have been developed to measure sleep quality, insom-nia, and daytime sleepiness (for review, see 3 ), but 2 of the most widely-used are the Pittsburgh Sleep Quality Index (PSQI) 4 and the Epworth Sleepiness Scale (ESS). 5,6 A search of the ISI Web of Knowledge Citation Index in January 2008 identified over 900 publications citing the PSQI, and over 1500 citing the ESS. Despite their widespread use, however, relatively little attention has been paid to how the PSQI and ESS relate to each other, or to other clinical and sleep measures.The PSQI is a 19-item self-rated questionnaire for evaluating subjective sleep quality over the previous month. The 19 questions are combined into 7 clinically-derived component scores, each weighted equally from 0-3. The 7 component scores are added to obtain a global score ranging from 0-21, with higher scores indicating worse sleep quality. The clinical and psychometric properties of the PSQI have been formally evaluated by several research groups. 4,[7][8][9] The PSQI has a sensitivity of 89.6% and specificity of 86.5% for identifying cases with sleep disorder, using a cut-off score of 5. Validity is further supported by similar differences between groups using PSQI or polysomnographic sleep measures. The PSQI has been translated into 48

Self‐perceived quality of sleep and mortality in Norwegian dialysis patients

“…These results are in concordance with the present study as neither PSQI nor ESS was related to mortality. However, Buysse et al 17 have pointed out that PSQI and ESS, gauges of quality of sleep and daytime sleepiness respectively, measure orthogonal dimensions of the sleep-wake experience. It is therefore interesting that the single question which assesses sleep quality was related to mortality while the questionnaires which embrace dimensions of daytime sleepiness were not.…”

“…from the sleep subscale from KDQoL-SF are valid instruments for both research and routine clinical practice. [15][16][17] These instruments measure different aspects of sleep quality which are important to assess. The aim of this study was therefore to assess the independent impact of sleep quality and daytime sleepiness on all-cause mortality in prevalent dialysis patients using different validated sleep questionnaires with special focus on the question "on a scale from 0-10, how would you evaluate your sleep?…”

Sleep Disturbance and Affective Comorbidity Among Episodic Migraineurs

“…Pittsburgh Sleep Quality Index 27 .-The Pittsburgh Sleep Quality Index (PSQI) is an 18-item measure of sleep quality that is often used as a means of identifying insomnia. 14 The validity of using PSQI scores >5 to differentiate "poor" from "good" sleepers has been established in multiple studies with both clinical and non-clinical samples. [27][28][29] Epworth Sleepiness Scale 30 .-The Epworth Sleepiness Scale (ESS) is an 8-item measure of daytime sleepiness that quantifies the likelihood of dozing during various activities.…”

“…Poor sleep quality and daytime sleepiness represent orthogonal constructs of sleep disturbance and are associated with poor health, significant functional and cognitive impairment, and psychiatric comorbidity. 14,15 Inadequate sleep hygiene (ISH) involves engaging in behaviors or maintaining a sleep environment not conducive to sleep (eg, frequent daytime napping, variable sleep-wake times, participating in stimulating activities before bed). Poor sleep hygiene appears to be a prominent contributor to sleep disturbance among patients with chronic migraine (CM), 16 and interventions to modify poor sleep hygiene have shown promise in reducing headache frequency among adults with CM 17 and children/adolescents with migraine.…”

Does abuse in late life worsen sleep quality? A two‐year prospective cohort study among rural older adults

“…Olofsson Test, but they are deemed less practical for clinical screening and research. 9 The Pittsburgh Sleep Quality Index (PSQI), on the other hand, is a validated, 19-item questionnaire which is widely used to measure sleep quality. 10 It has seven components-subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction-and has been cross-culturally validated.…”