REPRODUCIBILITY OF NORDIC SLEEP QUESTIONNAIRE IN SPINAL-CORD INJURED

A recently proposed Nordic Sleep Questionnaire (NSQ) comprises 26 ques tions concerning qualitative and quantitative aspects of the responden t's sleep habits. Its reproducibility was evaluated in 32 spinal cord injured individuals (SCI), 24 men and eight women (23-72 years), and 7 9 normal subjects, 23 men and 56 women (19-77 years). They completed t he NSQ twice at a median interval of 15 days (range 10-26) and 27 days (range 4-103) respectively. The group of normal subjects were evenly divided into group 26, i.e. those who completed the two NSQs within 26 days, and group 27 with 27 days or more between their replies. Genera lly, group 27 showed no worse test-retest agreement than group 26. In addition, the respondents' answers, with a few exceptions, were reason ably stable in terms of test-retest agreement or standard deviation. T he SCI group exhibited the same level of reproducibility, although the y had more 'pathology' to report and thus more scope for contradicting themselves. The questions in the NSQ generally were satisfactorily re producible. However, answers to the ordered five-point questions about sleepiness in the morning and during the daytime ought to be interpre ted with caution. The same may be said about the number of minutes req uired to fall asleep, and the duration of daytime naps.