Evaluating subjective sleep quality over a 1-month period.
Assessing the nature and severity of sleep disturbances in psychiatric and medical patients.
Monitoring the impact of interventions on sleep architecture and quality.
Screening for "poor sleepers" in epidemiological and clinical research.
Section 2
Formula & Logic
Scoring Component
The PSQI consists of 19 self-rated items which generate 7 component scores: Subjective Sleep Quality, Sleep Latency, Sleep Duration, Habitual Sleep Efficiency, Sleep Disturbances, Use of Sleeping Medication, and Daytime Dysfunction.
Global Score Interpretation
Score ≤ 5
Good sleeper
Score > 5
Poor sleeper (significant sleep difficulty)
Maximum Score
21
Section 3
Pearls/Pitfalls
Multi-Dimensional Data
The PSQI is superior to simpler tools like the ESS because it captures "Sleep Efficiency"—the ratio of time asleep to time in bed—which is a primary marker of insomnia severity.
Clinical Pearls
A global score of 5 has a sensitivity of 89.6% and specificity of 86.5% for identifying "poor" vs "good" sleepers.
Look specifically at Component 6 (Medication use); frequent use of sedatives may mask the underlying severity of components 1 and 2.
In patients with chronic pain or psychiatric disorders, the PSQI is often more sensitive than objective polysomnography to the patient's perceived level of suffering.
Section 4
Next Steps
Intervention Guidelines
01
Score > 5: Initiate a sleep log for 2 weeks. Screen for underlying medical causes (e.g., GERD, nocturia, chronic pain).
02
Low Efficiency (< 85%): Implement Sleep Restriction Therapy as part of a CBT-I program.
03
High Latency (> 30 min): Focus on Stimulus Control and pre-sleep relaxation techniques.
Section 5
Evidence Appraisal
Primary Reference
The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research
Buysse DJ et al. • Psychiatry Research. 1989;Vol 28, Issue 2. pp. 193-213. The original foundational paper.
Section 6
Literature
Daniel J. Buysse
Developed by Dr. Daniel Buysse and colleagues at the University of Pittsburgh. It remains the most widely cited and utilized tool for assessing subjective sleep quality globally.
