The occupational impact of sleep quality

2013-01-02T16:23:29Z (GMT) by Erica Kucharczyk
While the importance of assessing the occupational consequences of insomnia and other sleep disorders is emphasised in clinical nosologies and research guidelines, there is little consensus on which aspects of occupational performance should be assessed, how such impairment should be measured, and how outcomes should be reported. The research programme described in this thesis aimed to address this issue. Chapter 1 presents a systematic review and methodical critique of studies reporting those aspects of occupational performance most impacted by (or most frequently associated with) insomnia symptoms and degraded sleep quality. Equivocal results, wide variations in reporting conventions, and the overall lack of comparability among studies, strongly indicated the need to develop a standardised metric able to quantify sleep related occupational performance and serve as an assessment and outcome instrument suitable for use in research and clinical settings. Informed by the literature review, Chapters 2-4 describe the development and validation of the Loughborough Occupational Impact of Sleep Scale ( LOISS ), a unidimensional 19 item questionnaire that captures sleep-related occupational impairment across a number of workplace domains over a 4-week reference period. Chapters 5-7 describe LOISS outcomes from: i) surveys in a random population sample; ii) a representative sample of the UK workforce; and iii) a clinical sample of patients with obstructive sleep apnoea (before and after treatment with CPAP). Overall, the scale showed strong internal consistency (Cronbach s alpha range=0.84-0.94) and test-retest reliability (r=0.77, r2=0.59, p<0.001), high levels of criterion validity (significantly discriminating between good and poor sleepers), and proved an effective outcome measure in OSA. From the survey data reported in Chapters 2-7, LOISS score distributions showed no consistent gender difference but did show a significant ageing gradient, with sleep-related occupational impairment declining with increasing age. In conclusion, the work presented here supports the usability, validity and reliability of the LOISS as an assessment and outcome instrument, and also demonstrates the utility of this instrument in exploring the dynamics of sleep-related occupational performance