Sick and Tired: Understanding and Managing Sleep Difficulties in ...

participants, who may be less likely to attend support groups than women (Taylor,
Falke, Shoptaw, & Lichtman, 1986). Consequently it is difficult to generalise these
findings to males with FMS.
The cross-sectional nature of this study meant that only a „typical‟ or „average‟ nights
sleep was explored over the previous month and it is possible that participants‟ sleep
patterns may vary over time. It also remains inconclusive as to whether poor sleep leads
to poorer health outcome or vice versa, or if there is a bi-directional relationship
between sleep and pain. A further limitation of the cross-sectional design of the study is
that coping may have a more significant effect over time, which would not have been
accounted for in this research design. Indeed, Nicassio et al (1995) found that coping
explained more variance on levels of pain in the longitudinal analysis of their data than
during cross-sectional analysis. Therefore longitudinal research is needed to help clarify
the relationships and interactions between components of sleep and coping on health
outcomes. Future research may be enhanced by the use of sleep diaries which are
commonly used in research into insomnia and allow people to record sleep quality,
quantity and behaviour each day over several days or weeks (Affleck et al., 1998;
Moldofsky, 2009).
Fatigue was assessed as a single construct within this study which may be considered to
be another weakness of this study. As fatigue has been proposed to be a
multidimensional construct, the lack of a relationship between fatigue and sleep may
have been due to issues of measurement. Consequently, future studies need to
investigate the different dimensions of fatigue including mental fatigue (impairment in
concentration and thinking as a result of demanding or sustained activities) and physical
fatigue (a sense of physical exhaustion or depletion of energy as result of direct physical
effort) (Moldofsky, 2009).
Despite the limitations of this research, this study has revealed the important links
between sleep quality and a range of quality of life outcomes in FMS. This work builds
on previous research findings by exploring the components of sleep quality and
highlighting the most prevalent sleep difficulties in order to inform clinical treatment.
The results highlight the need for careful comparison of results from studies which use
assessments of coping and also the need to assess a range of health outcomes in research
into the complex condition of FMS.
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