Psychometric properties of the Pre-Sleep Arousal Scale in a large community sample

The purpose was to examine the psychometric properties of the Pre-Sleep Arousal Scale.

From a randomly selected sample of the general population (N=5000), 2327 participants completed a survey on nighttime symptoms, daytime symptoms, health outcomes, and psychological processes. The study sample consisted of 1890 participants who did not fulfill criteria for a sleep disorder other than insomnia.

Findings indicated that the PSAS did not produce an adequate factorial solution. When three problematic items were removed, the solution, accounting for 48.5% of the variance, improved (PSAS-13). One subscale, cognitive arousal (α=.88), consisted of five items (37.1%), and one subscale, somatic arousal (α=.72), of eight items (11.4%). The two factors were significantly inter-correlated (ρ=.51) and associated with the PSAS-13 (ρ=.91, ρ=.80). Among those with insomnia, a shortened PSAS (PSAS-14) was established, which consisted of a cognitive and a somatic subscale (48.6% of the variance). The PSAS-13 and the two subscales showed discriminant validity between three sleep groups (normal sleep, poor sleep, and insomnia disorder) (R(2)=.24-.34). The PSAS-13 and the subscales demonstrated convergent validity with measures on sleep-related worry, sleep-related beliefs, anxiety, and depression. The PSAS-13 and the two subscales were significantly correlated with sleep parameters and daytime impairment.

Though acceptable psychometric properties were established for the PSAS, the cognitive subscale's focus upon general pre-sleep arousal and the relatively low variance accounted for calls for further work on and a possible re-conceptualization of the PSAS.