The Pittsburgh Sleep Quality Index (PSQI) is widely used, but can be impractical in large studies due to its length. The two-item version (PSQI-2) is a promising alternative, with underexplored longitudinal properties in older adults. We evaluated its validity against the full PSQI in the MrOS Sleep Study cohort of older men. Cross-sectional validity (Bland-Altman, ROC curves for PSQI > 5) and longitudinal properties (ICC, change score correlation, accuracy for ΔPSQI > 3) were assessed. The PSQI-2 showed a strong cross-sectional association with the full PSQI (b = 2.167, p 3). The PSQI-2 is a valid and reliable tool for cross-sectional screening of poor sleep quality in older men at the cutoff of ≥2. It is also responsive to directional change over time and can identify individuals with clinically significant changes in sleep.
Luiz Menezes-Júnior (Mon,) studied this question.