Behavioural therapy for shift work disorder improves shift workers' sleep, sleepiness and mental health: A pilot randomised control trial

The experiences of night shift workers following three different dietary weight loss interventions: a qualitative study using behaviour change theory

BACKGROUND

Shift workers are an estimated 15%-30% of the workforce in developed countries, who are disproportionally at risk of living with overweight or obesity. Dietary guidance is a component recommended for obesity management, however lacks consideration of the lifestyle and circadian disruption experienced by night shift workers. There is a lack of evidence addressing both weight loss and the metabolic consequences of eating at night. Intermittent fasting (IF) may provide metabolic benefits if fasting is aligned with night shifts. The Shifting Weight using Intermittent Fasting in night shift workers study compares three weight-loss interventions: 1) continuous energy restriction (CER); or twice-per-week IF with 2) fasting during night shifts or 3) day fasting. This study aims to explore the experiences of participants while following the interventions to understand how intervention features and external enablers or barriers influence engagement.

METHODS

Forty-seven semi-structured interviews (22 baseline, 25 follow-up) were conducted with 33 participants. Eighteen participants also completed optional fortnightly audio diaries to enrich data collected on experiences over time. Interviews and diaries were analysed using the five-steps of framework analysis and themes were deductively mapped to behaviour change frameworks and the social-ecological model.

RESULTS

Analysis resulted in seven major themes and 27 subthemes. Three main themes describe intervention factors influencing engagement: 1) Simplicity and ease, 2) Support and accountability, and 3) An individualised approach is sometimes needed. Four themes described external factors to the interventions influencing engagement: 4) Personal motivation and attitudes, 5) Physiological influences of eating behaviours, 6) Social support at home and work, and 7) Work structure and environment.

CONCLUSIONS

Across all three interventions, participants valued the ease of interventions, which was the clear dietary prescription and focus on two days per week for IF, or a focus on small changes for CER. Behavioural regulation and providing meals/snacks were identified as critical features. Modifications to address identified enablers/barriers include: providing flexible fasting periods; addition of fatigue management initiatives; increased focus on non-weight related health changes during periods of slowed weight-loss; implementation in workplace settings to harness social support; and providing a healthier food environment.

Comparison of Tailored Versus Standard Group Cognitive Behavioral Therapy for Shift Worker Insomnia: A Randomized Controlled Trial

Shift workers are at increased risk of insomnia. The standard treatment (cognitive behavioral therapy for insomnia) poses significant challenges for this demographic due to irregular work and sleep schedules. New approaches are still considered insufficient due to high attrition or insufficient effectiveness. Our preliminary study identified sleep-relevant state and trait factors (see secondary outcomes) for incorporation into an innovative manual that addresses sleep in an implicit manner. The objective was to reduce the focus on insomnia and to replace regularity-based interventions. With a sample of 55 insomniacs (67.74% male, mean age 41.62 years), standard and customized treatments were compared using pre-treatment, post-treatment, and three-month follow-up measurements (RCT, self-assessment data). Our linear mixed models revealed the main significant effects of the measurement point for the primary (insomnia severity, sleep quality, sleep onset latency, total sleep time, daytime sleepiness) and the secondary outcomes (selection: anxiety/depression, dysfunctional beliefs, arousal, emotional stability, concern). No main effects of the condition or interaction effects were identified. Non-inferiority and equivalence tests demonstrated that the customized treatment is equivalent to standard therapy, which is a favorable outcome in light of the implicit approach. Consequently, this innovative approach warrants further exploration, incorporating the present results.

Better sleep hygiene is associated with better sleep health in mining shift workers in Australia

Australia's mine sites are largely situated in remote locations and operate around the clock. Many shift workers fly to site, where they work 12-hr shifts and sleep in camp accommodation before they return home for the period rostered off work. Mining shift workers experience poor sleep, yet limited research is available on contributing factors. This study investigated, for the first time, the relationship between the sleep health and sleep hygiene in this population. A survey was disseminated to shift workers in the mining industry, utilising a cross-sectional study design. The Sleep Health Index and Sleep Hygiene Index questionnaires were used to evaluate their sleep health and sleep hygiene, respectively. In total, 470 shift workers (mean age [years]: 39 ± 12, mean body mass index [kg m-2]: 28 ± 5) were included, which involved 132 females. Average scores for the Sleep Health Index and Sleep Hygiene Index were 76 ± 15 and 30 ± 7, respectively. Better sleep health was observed in shift workers with better sleep hygiene (β = -0.52, SE = 0.09 [-0.71, -0.34], p < 0.001). Differences in Sleep Health Index scores were found for individual Sleep Hygiene Index items related to "sleep regularity", "sleep environment", "mental health" and "time in bed extension". However, no differences in Sleep Health Index scores were found for items related to "caffeine, alcohol or nicotine consumption" or "exercise" close to bedtime and "bedtime activities" (p > 0.05 for all). These findings demonstrate a relationship between sleep hygiene and sleep health; therefore, it may be possible to improve the sleep of shift workers by improving their sleep hygiene.

Efficacy study comparing a CBT-I developed for shift workers (CBT-I-S) to standard CBT-I (cognitive behavioural therapy for insomnia) on sleep onset latency, total sleep time, subjective sleep quality, and daytime sleepiness: study protocol for a parallel group randomised controlled trial with online therapy groups of seven sessions each

BACKGROUND

Shift workers are at an increased risk of developing sleep disorders. The standard therapy recommended for sleep disorders is cognitive behavioural therapy for insomnia (CBT-I). Many of its interventions are based on a regular sleep and wake rhythm, which is difficult to apply for shift workers. We have therefore developed a new therapy manual specifically for shift workers (CBT-I-S), which should be more applicable to their needs. In particular, all interventions that require regularity have been removed, and instead, interventions that address factors that proved to be relevant to sleep in our preliminary study have been integrated. We now want to test this manual for its effectiveness.

METHODS

A randomised controlled trial with N = 142 will be conducted to compare two conditions: the newly developed therapy manual will be carried out in the experimental group, while cognitive behavioural therapy for insomnia will be employed in the standard group. Both treatments will be conducted online via MS Teams in a group setting with seven sessions each. Data will be collected at three measurement points (pre, post, 6-month follow-up) and analysed using linear mixed models. The study will investigate whether the two treatments have led to significant improvements in total sleep time, sleep onset latency, subjective sleep quality and daytime sleepiness in shift workers. It will also examine whether the new therapy manual is superior to standard therapy in shift workers and whether these effects are stable.

DISCUSSION

We assume that interventions designed to address depressive mood, anxiety, worry, rumination, dysfunctional thought patterns and attitudes towards sleep will also improve sleep. If this is indeed the case, these interventions could replace previous ones that require regularity. This could significantly improve the treatment of insomnia in shift workers.

TRIAL REGISTRATION

German Clinical Trials Registry DRKS DRKS00032086 . Registered on August 16, 2023.