PSQI Sleep Quality Assessment
The Pittsburgh Sleep Quality Index (PSQI) is a widely used, validated self-report questionnaire that assesses sleep quality and disturbances over a one-month retrospective interval. Developed by Buysse et al. (1989), the instrument evaluates seven clinically derived components of sleep: subjective sleep quality, sleep latency (time to fall asleep), sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each component is scored on a 0–3 scale, yielding a global PSQI score ranging from 0 (no sleep difficulty) to 21 (severe sleep difficulties). A cutoff global score greater than 5 has been shown to identify clinical sleep disorders with a sensitivity of 89.6% and a specificity of 86.5% in the original validation study. This abbreviated implementation preserves all seven PSQI component scoring rules in a structured four-step interface.
Sleep Quality Assessment
Answer the following questions based on your sleep patterns during the past month. Click an option to select it.
Data Source and References
- [1] Buysse DJ, Reynolds CF III, Monk TH, Berman SR, Kupfer DJ (1989). The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Research, 28(2):193–213. doi.org
- [2] Mollaye M, Hossein Zadeh R, Rajabi S, Abdollahi M, Ghayyem V, Mollayeva T (2016). The Pittsburgh Sleep Quality Index as a measure of sleep quality: a systematic review of the literature. Journal of Clinical Sleep Medicine, 12(1):129–138. (Cross-cultural validation review)
- [3] American Academy of Sleep Medicine. International Classification of Sleep Disorders, 3rd ed. (ICSD-3). Darien, IL: AASM; 2014.
PSQI Scoring: Component Rules and Clinical Interpretation
The Pittsburgh Sleep Quality Index operationalizes the construct of sleep quality into seven weighted (0–3) component scores that are summed to produce a global score ranging from 0 to 21. Lower scores indicate better sleep quality. Component 1 (Subjective Sleep Quality) is the self-report global rating (Q9) scored directly. Component 2 (Sleep Latency) combines the self-reported time to fall asleep (Q2) with the frequency of delayed sleep onset beyond 30 minutes (Q5a): the raw item sum of these two items is mapped into component scores of 0 (sum = 0), 1 (sum = 1–2), 2 (sum = 3–4), or 3 (sum = 5–6). Component 3 (Sleep Duration) is scored from nightly sleep hours: > 7 h = 0, 6–7 h = 1, 5–6 h = 2, < 5 h = 3. Component 4 (Habitual Sleep Efficiency) is computed as the ratio of hours actually slept to hours spent in bed (derived from bedtime minus wake time), scored as > 85% = 0, 75–84% = 1, 65–74% = 2, < 65% = 3. Component 5 (Sleep Disturbances) sums the nine Q5 subitems (b through j) rated on 0–3 frequency scales; the summed aggregate is rebinned: 0 → 0, 1–9 → 1, 10–18 → 2, 19–27 → 3. Component 6 (Sleep Medication) scores Q6 directly. Component 7 (Daytime Dysfunction) sums the 0–3 ratings of daytime sleepiness (Q7) and enthusiasm deficit (Q8) and rebins identically to the latency component: 0 → 0, 1–2 → 1, 3–4 → 2, 5–6 → 3.
PSQI Score Categories
| Score Range | Category | Color | Interpretation |
|---|---|---|---|
| 0 – 5 | Good sleep quality | Green | Sleep is generally restorative; no clinically significant sleep disturbance indicated. |
| 6 – 10 | Mild / Fair sleep quality | Yellow | Noticeable sleep complaints that may affect daytime function. Consider sleep hygiene review. |
| 11 – 15 | Moderate / Poor sleep quality | Red | Significant sleep impairment likely. Clinical evaluation recommended. |
| 16 – 21 | Severe / Very poor sleep quality | Dark Red | Severe sleep disturbance with marked daytime impact. Prompt specialist consultation advised. |
Validation Characteristics
The original Buysse et al. (1989) validation compared 52 patients with confirmed psychiatric or sleep disorders against 167 self-described "good sleepers." At the conventional cutoff of a global PSQI score greater than 5, the instrument correctly classified 89.6% of clinical cases (sensitivity) and 86.5% of controls (specificity). The positive likelihood ratio at this cutoff is approximately 6.6, and the negative likelihood ratio is approximately 0.12, producing a diagnostic odds ratio of about 55 — indicating substantial discriminative utility. Test–retest reliability (r = 0.85 over 2–3 days) and internal consistency (Cronbach's alpha = 0.83) support the instrument's psychometric properties. The PSQI has been translated and validated in over 50 linguistic and cultural populations (Mollaye et al. 2016).
Frequently Asked Questions
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The original Buysse et al. (1989) validation study established a global PSQI cutoff score greater than 5 as the optimal threshold for discriminating between individuals with clinical sleep or psychiatric disorders and good sleepers. At this cutoff, the PSQI achieves a sensitivity of 89.6% (correctly identifying 89.6% of true cases) and a specificity of 86.5% (correctly classifying 86.5% of controls). Scoring above this threshold does not constitute a diagnosis but does warrant further clinical evaluation, particularly if daytime impairment is present.
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Each of the seven PSQI components ranges from 0 to 3. C1 (Subjective Quality) is Q9 scored directly (very good→0 to very bad→3). C2 (Sleep Latency) sums Q2 and Q5a raw scores: 0→0, 1–2→1, 3–4→2, 5–6→3. C3 (Duration) scores Q4 by hours: >7h→0, 6–7h→1, 5–6h→2, <5h→3. C4 (Efficiency) scores (asleep hours ÷ in-bed hours×100): >85%→0, 75–84%→1, 65–74%→2, <65%→3. C5 (Disturbances) sums all nine Q5b–j items: 0→0, 1–9→1, 10–18→2, 19–27→3. C6 (Medication) is Q6 scored directly. C7 (Daytime) sums Q7 and Q8 raw scores: 0→0, 1–2→1, 3–4→2, 5–6→3. Total = C1+C2+C3+C4+C5+C6+C7.
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The PSQI is explicitly designed for a one-month retrospective reporting window. All questions should be answered by considering your sleep patterns "during the past month" — averaging across both typical and atypical nights within that interval. This intentional design smooths day-to-day variability and better captures persistent, clinically meaningful sleep patterns rather than transient fluctuations caused by isolated stress, travel, or acute illness.
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No. The PSQI is a broad screening instrument for overall sleep quality and disturbance severity; it is not a diagnostic test for any specific sleep disorder per the International Classification of Sleep Disorders (ICSD-3). An elevated PSQI score cannot differentiate insomnia disorder, obstructive sleep apnea, restless legs syndrome, circadian rhythm sleep–wake disorder, or narcolepsy from one another. Differential diagnosis requires targeted history, polysomnography, actigraphy, or other specialized assessments directed by a qualified sleep medicine clinician.