Sleep quality and daytime functioning in primary insomnia: a prospective study

In a 9-month prospective study, sleep and daytime functioning were compared in a community sample of 86 participants aged 25-50 years: 43 meeting DSM IV criteria for primary insomnia (26 women & 17 men); and 43 controls (32 women & 11 men). Assessments were conducted at baseline, 4 and 8 months, and included: the Pittsburgh Sleep Quality Index; Spielberger StatefTrait Anxiety Inventory; Eysenck Personality Questionnaire, Beck Depression Inventory; Fatigue Severity Scale; SF-36; Epworth Sleepiness Scale; Dysfunctional Beliefs About Sleep Scale; Sleep Hygiene and Practices Scale, Sleep Disturbance Questionnaire and the Psychomotor Vigilance Task PVT. An instrument to assess the occupational consequences of insomnia (the Occupational Impact of Sleep Questionnaire; OISQ) was also developed in the course of the study. PWI versus control group comparisons were made with repeated measures multivariate ANOVAs. Differences were consistently and significantly maintained on measures of state (F = 15.85 P <0.001) and trait anxiety (F = 23.46; P < 0.001), depression (F = 18.37; P < 0.001), fatigue (F = 22.20; P < 0.001), and neuroticism (F = 11.09; P < 0.001). Among PWI, mental health (F = 14.04; P < 0.001), pain (F = 6.92; P < 0.001), role-emotion (F = 10.94; p < 0.001), general health perceptions (F = 4.77; P < 0.05), social functioning (F = 6.58; P < 0.01) and energy and vitality (F = 32.08; P < 0.001), on the SF-36, were consistent with inferior health related QoL. In addition, pre-sleep arousal (F = 14.76; P < 0.001), sleep hygiene (F = 35.26; P < 0.001) and sleep disturbance (F = 72.32; P < 0.001) were significantly worse within PWI. Subjectively reported TIB (F = 9.38; P < 0.01), SOL (F = 11.17; P < 0.01) and WASO (F = 21.10; P < 0.001), remained greater within PWI, with SE (F = 15.29; P < 0.001), TST (F = 9.38; P < 0.01) and subjective sleep quality (F = 29.57; P < 0.001) greater within controls.Data averaged over the duration of data collection (252 days) found PWI reported an average SOL >30 minutes, an average WASO of> 30 minutes, SE < 80%. Analysed in terms of night to night sleep quality, both PWI and controls showed a pattern of 'good' (sleep efficiency >80%) and 'poor' (sleep efficiency