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The PSQI demonstrates better psychometric performance as a multidimensional measure, particularly a two-factor structure, than as a single global score in young South African women.

In a large sample of 7182 young women in Soweto, South Africa, the PSQI showed modest internal consistency (α=.57, ω=.57) and poor fit for the one-factor model (CFI=.65, RMSEA=.13), but good fit for the two-factor (CFI=.94, RMSEA=.05) and three-factor (CFI=.94, RMSEA=.06) models. The two-factor model was slightly better and recommended for use in this population.

Last updated: Aug 15, 2026•0 RCTs•📖 Read as article →

Evidence Score

Evidence Score32/100
Human RCT☆☆☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★★★☆
Confidencelow

Study Evidence

Study 1. Psychometric evaluation of the Pittsburgh Sleep Quality Index among South African women participating in the Bukhali trial: Healthy Life Trajectories Initiative.

observational

Alcock S, Beukes J, Hart C, Scheuermaier K, Lye SJ, Norris SA · Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine (2026)

Participants: N/A
Duration: Not specified (cross-sectional baseline data)
Intervention: Psychometric evaluation of the PSQI (no intervention)
Outcome: PSQI factor structure, internal consistency, model fit indices (CFI, TLI, RMSEA)
Effect Size: N/A
Population: 7182 young women (mean age not specified) enrolled in the Bukhali trial in Soweto, South Africa

Result:

PubMed: 42547644DOI: 10.1007/s44470-026-00146-z

Mechanism Graph

PSQI items were administered via interviewer-administered surveys
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Internal consistency assessed via Cronbach's alpha, McDonald's omega, item-total correlations
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Confirmatory factor analysis tested one-, two-, and three-factor models
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Two-factor model showed best fit, indicating multidimensional structure

Limitations

  • ⚠Cross-sectional design; no test-retest reliability assessed
  • ⚠Sample limited to young women in an urban South African setting, limiting generalizability
  • ⚠Interviewer-administered surveys may introduce social desirability bias

Frequently Asked Questions

What is the recommended way to score the PSQI in this population?▼

The two-factor model is recommended over the global score, as it showed better fit and provides more meaningful insight into sleep quality.

What were the main sleep problems in this cohort?▼

Sleep problems were driven by fragmented sleep and continuity disruptions rather than insufficient sleep opportunity, with average sleep of 7.8 hours but prolonged onset latency and high fragmentation.

How reliable was the PSQI in this study?▼

Internal consistency was modest with Cronbach's alpha and McDonald's omega both at .57, indicating lower reliability than typically desired.

What factors were associated with poor sleep quality?▼

Poor sleep quality was associated with higher household socioeconomic status, higher education, and single relationship status.

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References

  1. 1.Alcock S, Beukes J, Hart C, Scheuermaier K, Lye SJ, Norris SA. "Psychometric evaluation of the Pittsburgh Sleep Quality Index among South African women participating in the Bukhali trial: Healthy Life Trajectories Initiative.." Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 2026. PMID: 42547644 DOI: 10.1007/s44470-026-00146-z
Disclaimer: This content is for educational purposes only and is not medical advice. Evidence scores reflect the quality and quantity of available research, not clinical recommendations. Always consult a healthcare professional before starting any supplement or intervention.