... coefficient are restricted to the nullhypothesis of zero correlation, not to the strength of the correlation, the magnitude of the correlations between the Sleep Quality Scale and the MOS Sleep Scale ... health-related quality of life, depression, and cogni-tive difficulties [4]. Assessing the effectiveness of new ther-apies therefore requires accurate assessment of a multi-dimensional array of symptoms ... reports the psychometric properties of the dailydiary Sleep Quality Scale using data from two rand-omized, double-blind, placebo-controlled clinical trials of pregabalin conducted in the United...