title: Temporal Stability of the Ford Insomnia Response to Stress Test (FIRST).
abstract: The Ford Insomnia Response to Stress Test (FIRST) is a self-report tool that measures sleep reactivity (i.e., vulnerability to experience situational insomnia under stressful conditions). Sleep reactivity has been termed a "trait-like" vulnerability; however, evidence of its long-term stability is lacking. The main objective of the current psychometric study was to investigate the temporal stability of the FIRST over two 6-mo intervals in a population-based sample of adults with and without insomnia. The temporal stability of the FIRST was also compared with the temporal stability of other scales associated with insomnia (trait-anxiety, arousability).
  
  
  
  Participants included 1,122 adults (mean age = 49.9 y, standard deviation = 14.8; 38.8% male) presenting with an insomnia syndrome (n = 159), insomnia symptoms (n = 152), or good sleep (n = 811). Participants completed the FIRST, the State-Trait Anxiety Inventory (trait-anxiety), and the Arousal Predisposition Scale (arousability) on three different occasions: baseline and at 6- and 12-mo follow-up. Intraclass correlation coefficients (ICCs) were computed for all scales (baseline to 6 mo and 6 to 12 mo).
  
  
  
  The FIRST yielded strong temporal stability from baseline to 6 mo among those with insomnia syndrome (ICC = 0.81), symptoms (ICC = 0.78), and good sleep (ICC = 0.81). Similar results were observed for 6 to 12 mo among those with insomnia syndrome (ICC = 0.74), insomnia symptoms (ICC = 0.82), and good sleep (ICC = 0.84). The stability of the FIRST was not comparable with the stability of trait-anxiety, but was somewhat comparable with the stability of arousability.
  
  
  
  Overall, the FIRST is a temporally reliable stable scale over 6-mo intervals. Future research is needed to corroborate the stability and trait-like measures of sleep reactivity with physiological, behavioural and personality measures.
authors: École de Psychologie, Université Laval, Québec City, Québec, Canada.|Centre d'étude des Troubles du Sommeil, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec, Canada.
authors: Denise C
authors: DC
authors: Jarrin
authors: École de Psychologie, Université Laval, Québec City, Québec, Canada.|Centre d'étude des Troubles du Sommeil, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec, Canada.
authors: Ivy Y
authors: IY
authors: Chen
authors: École de Psychologie, Université Laval, Québec City, Québec, Canada.|Centre d'étude des Troubles du Sommeil, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec, Canada.
authors: Hans
authors: H
authors: Ivers
authors: Henry Ford Hospital, Detroit, MI.
authors: Christopher L
authors: CL
authors: Drake
authors: École de Psychologie, Université Laval, Québec City, Québec, Canada.|Centre d'étude des Troubles du Sommeil, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec, Canada.
authors: Charles M
authors: CM
authors: Morin
mesh_terms: D000223:Adaptation, Psychological; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D057566:Self Report / Q000592:standards*; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis* / Q000523:psychology*; D013315:Stress, Psychological / Q000523:psychology*; D011795:Surveys and Questionnaires / Q000592:standards*; D013995:Time
keywords: insomnia; psychometrics; reliability; sleep reactivity; temporal stability