title: Psychometric properties of an insomnia-specific measure of worry: the Anxiety and Preoccupation about Sleep Questionnaire.
abstract: The aim of this study was to examine the psychometric properties of the Anxiety and Preoccupation about Sleep Questionnaire (APSQ), with a focus on factorial validity and internal consistency as well as discriminative, convergent, and association with sleep parameters and daytime impairment. Among a randomly selected sample from the general population (N = 5,000), 2,333 participants completed a survey on nighttime symptoms, daytime symptoms, health outcomes, and psychological processes. The study sample consisted of 1800 participants who did not fulfill criteria for another sleep disorder than insomnia. A two-factor solution, accounting for 70.7% of the variance, was extracted from the 10 APSQ items. One six-item factor determined worries about the consequences of poor sleep (α = .91); the second factor, with four items, assessed worries about the uncontrollability of sleep (α = .86). The two factors were significantly intercorrelated (ρ = .65) and significantly associated with the total APSQ (ρs = .97 and .76, respectively). The APSQ and the two subscales showed discriminant validity between three sleep status groups (normal sleep, poor sleep, and insomnia disorder; R(2) = .33-.41). The APSQ and the subscales demonstrated convergent validity with measures on cognitive arousal, sleep-related beliefs, anxiety, and depression. They also were significantly correlated with sleep parameters and daytime impairment. The findings suggest that the APSQ is a psychometrically sound instrument for assessing worry in insomnia.
authors.affiliation: School of Law, Psychology, and Social Work, Orebro University, Sweden. markus.jansson@oru.se
authors.forename: Markus
authors.initials: M
authors.lastname: Jansson-Frojmark
authors.forename: Allison G
authors.initials: AG
authors.lastname: Harvey
authors.forename: Lars-Gunnar
authors.initials: LG
authors.lastname: Lundh
authors.forename: Annika
authors.initials: A
authors.lastname: Norell-Clarke
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Linton
mesh_terms: D000328:Adult; D001007:Anxiety / Q000175:diagnosis / Q000523:psychology*; D001143:Arousal; D003863:Depression / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000523:psychology*; D013315:Stress, Psychological / Q000523:psychology*; D011795:Surveys and Questionnaires; D013850:Thinking