Developing and Testing an intervention for shiftwork sleep disorder in NHS workers

Shiftwork is prevalent and is a major challenge to the healthy circadian organisation of human behaviour. Shiftwork increases risk for multiple adverse physical and mental health outcomes, including changes in brain structure, depression, relationship breakdown, cancer, obesity, type 2 diabetes, stroke, and inflammatory diseases. The most common adverse consequence of shiftwork is shiftwork associated sleep disorder (SWD). This affects about 30% of shift workers, and is characterised by insomnia on rest periods, and impaired vigilance during work periods. There is currently no therapeutic option for the disorder, which is not widely recognised. Despite recommendations that shift workers should not resort to hypnotics, it is estimated that at least 10% do.

The mechanism driving SWD is circadian misalignment, with difficulties encountered by affected people trying to sleep, or work against their endogenous circadian clock. We now understand how important the circadian clock, and its outputs are for brain health, and there is some evidence that variation in human circadian characteristics intersect with the shiftwork exposure to drive adverse outcomes. This understanding of mechanisms underpins promising interventions and targets potential modifiers of effect.

We have worked on behavioural approaches for sleep disorders and have identified, and proven some manipulations that are scalable, and effective in improving sleep. In addition, we now know how to affect the phase of the endogenous circadian oscillator using ambient light, physical activity, and eating. Taken together we now have a toolkit of potential intervention strategies that we can apply to people with SWD.

develop a multicomponent intervention for SWD in NHS staff. Once acceptability is demonstrated we will move to large-scale testing in a prospective pragmatic trial.

We estimate that our analysis of current interventions used to address SWD in NHS staff will require a survey in approximately two large NHS hospital Trusts. The randomised controlled trial will require 20-25 NHS hospital Trusts, based on a prevalence of SWD in shiftworkers of about 30%. We calculate the group sizes required to be approximately 300.

As we test these components, we will also conduct research into the prevalence, current therapeutic option efficacy, context, and both mitigating and exacerbating factors using conventional approaches analysing published and grey literature sources, survey, and expert advisory group approaches, and analysis of large human cohorts with defined shiftwork exposure. These approaches will help in the development of the intervention components and will also aid in their implementation. We will identify costs and quantify benefits which will be essential for regulatory approval, and to support implementation within the NHS.

Shiftwork is not confined to the NHS and through the programme we will identify barriers and opportunities for implementation of our intervention within other industrial sectors. We will accomplish this by including non-NHS experts within our expert advisory group.

In addition, we will systematically review the literature, understand SWD better in healthcare workers (target population) and healthcare context, and leverage existing datasets (alongside strong PPIEP) to