Subjective assessment of sleep by Sleep Questionnaire

A 55-item Sleep Questionnaire is presented for possible use as a standardized instrument in psychological studies of sleep. A factor analysis of responses from 145 adults to the questionnaire indicated 7 factors accounted for 71.7% of the total variance. These factors are congruent with sleep dimensions discussed in the literature and with other factor analytic investigations. A set of 11 clinical judgment scales are also presented. The reliabilities of both factor and clinical scales are adequate as judged by test-retest, internal consistency, and comparisons of self vs spouse ratings. The construct validity is supported by three studies showing significant differences between (a) medical patients with and without sleep disturbances, (b) psychiatric patients with and without symptoms of depression, and (c) short and long sleepers.