title: Does self-efficacy mediate the relationship between transformational leadership behaviours and healthcare workers' sleep quality? A longitudinal study.
abstract: OBJECTIVE
  This paper is a report of a study conducted to investigate the longitudinal relationship between transformational leadership behaviours and employees' sleep quality, and the mediating effects of self-efficacy.
  
  
  BACKGROUND
  Although there is evidence for the influential role of transformational leadership on health outcomes, researchers have used either attitude outcomes (e.g. job satisfaction) or softer health measures, such as general well-being. Specific measures of well-being such as sleep quality have not been used, despite its association with working conditions.
  
  
  METHODS
  A longitudinal design was used to collect data from Danish healthcare workers at time 1 in 2005 (n = 447) and 18 months later at time 2 in 2007 (n = 274). Structural equation modelling was used to investigate the relationships between transformational leadership, self-efficacy and sleep quality at both time points independently (cross-sectionally) and longitudinally.
  
  
  RESULTS
  For all constructs, time 2 measures were influenced by the baseline level. Direct relationships between transformational leadership and sleep quality were found. This relationship was negative cross-sectionally at both time points, but positive between baseline and follow-up. The relationship between leadership and employees' sleep quality was not mediated by employees' self-efficacy.
  
  
  CONCLUSIONS
  Our results indicate that training managers in transformational leadership behaviours may have a positive impact on healthcare workers' health over time. However, more research is needed to examine the mechanisms by which transformational leadership brings about improved sleep quality; self-efficacy was not found to be the explanation.
authors.affiliation: Department of Human Sciences, Loughborough University, United Kingdom. f.munir@lboro.ac.uk
authors.forename: Fehmidah
authors.initials: F
authors.lastname: Munir
authors.forename: Karina
authors.initials: K
authors.lastname: Nielsen
mesh_terms: D000328:Adult; D003718:Denmark; D005260:Female; D006801:Humans; D007588:Job Satisfaction; D007857:Leadership; D008137:Longitudinal Studies; D008297:Male; D008962:Models, Theoretical; D009728:Nursing Assistants / Q000523:psychology; D009741:Nursing Staff, Hospital / Q000523:psychology* / Q000706:statistics & numerical data; D020377:Self Efficacy; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology* / Q000523:psychology; D011795:Surveys and Questionnaires