RESEARCH MOTIVATION AND PURPOSE

Prevalence of Shift Work and Associated Insomnia:

‧ Shift work is common in modern workplaces, where non-traditional hours disrupt the natural circadian rhythm.

‧ This disruption often leads to chronic sleep disturbances, significantly affecting both the health and work performance of employees.

‧ Insomnia among shift workers has become a critical issue, prompting the need

Limitations of Conventional Treatments:

‧ Most existing insomnia treatments rely on pharmacological approaches. Although medications can offer quick relief, they come with drawbacks such as side effects, dependency risks, and withdrawal issues.

‧ Long-term medication use is not ideal because of these adverse effects, making non-drug alternatives more appealing.

THE OBJECTIVES

‧ The study aimed to assess whether a self-help Cognitive Behavioral Therapy for Insomnia (CBT-I) program could effectively improve sleep quality among shift workers.

‧ By delivering the intervention in an online, self-guided format, the study intended to provide a low-cost, easily accessible alternative that could reduce reliance on medications.

‧ The program was also designed to incorporate real-time feedback and selfmonitoring through sleep diaries, which might enhance adherence and personalize recommendations.

LITERATURE REVIEW

Impact of Shift Work on Sleep:

‧ Shift workers often experience disrupted sleep patterns, including prolonged sleep onset, fragmented sleep, and lower sleep quality.

‧ Research from various regions (e.g., Taiwan, China, and Europe) shows that a substantial portion of the workforce engages in shift work, making insomnia a widespread issue.

‧ Poor sleep quality is linked to higher risks of chronic conditions such as hypertension, mental health issues, and metabolic disorders.

Comparison of Pharmacological and Non-Pharmacological Approaches:

Pharmacotherapy:

‧ Medications like benzodiazepines and non-benzodiazepines are commonly prescribed; however, their use is limited by potential side effects, dependency, and guidelines that restrict long-term usage.

‧ Clinical recommendations suggest short-term use of hypnotics, usually no longer than 4 to 5 weeks.

Cognitive Behavioral Therapy for Insomnia (CBT-I):

‧ CBT-I is well-supported by evidence as an effective treatment for insomnia, capable of providing sustained improvements in sleep quality without the risks associated with medications.

‧ Traditional CBT-I involves stimulus control, sleep restriction, relaxation training, cognitive restructuring, and sleep hygiene education.

‧ Its effectiveness is further enhanced when tailored to address the specific sleep disturbances associated with shift work.

Rationale for a Self-Help Format:

‧ The shortage of trained professionals makes it challenging to deliver traditional CBT-I to all who need it, particularly in regions with limited mental health resources.

‧ Self-help CBT-I programs, like the “Refresh” module developed at Stanford, offer a practical solution. They provide structured materials covering key topics such as sleep stages, biological clocks, sleep restrictions, and cognitive strategies.

‧ Integrating automated feedback mechanisms and daily sleep diaries into the program allows for personalized guidance, potentially improving adherence and treatment outcomes.

RESEARCH METHODS

Study Design and Participant Recruitment:

‧ A crossover experimental design (ABBA sequence) was employed to control for individual differences.

‧ Participants were recruited from a large factory in Shanghai operating a twoshift system (day and night shifts).

‧ Out of 125 initial recruits, 85 shift workers met the inclusion criteria (e.g., significant sleep onset delays and high scores on either the Insomnia Severity Index [ISI] or the Pittsburgh Sleep Quality Index [PSQI]).

‧ Exclusion criteria eliminated individuals with long-term medication use, substance abuse, significant medical conditions, or major psychiatric disorders.

Intervention Details:

‧ The eight-week intervention consisted of online self-help CBT-I modules (using the “Refresh” materials) covering:

  ➤ Education on sleep stages, the biological clock, and sleep regulation.

  ➤ Techniques include sleep restriction, stimulus control, relaxation training, mindfulness, and cognitive restructuring.

  ➤ Strategies for preventing relapse.

‧ Participants maintained a daily online sleep diary documenting sleep timings, latency, total sleep time, and perceived sleep quality.

‧ An automated feedback system provided rule-based recommendations (e.g., adjusting nap length or sleep times) based on diary inputs.

‧ The crossover design allowed one group to receive the intervention first while the other acted as a waiting-list control, and then switched roles.

MEASUREMENT INSTRUMENTS

‧ Insomnia Severity Index (ISI): Measures the intensity of insomnia symptoms and their impact.

‧ Pittsburgh Sleep Quality Index (PSQI): Assesses overall sleep quality, including subjective quality, sleep latency, and daytime dysfunction.

‧ Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16): Evaluates maladaptive beliefs regarding sleep.

‧ General Self-Efficacy Scale (GSES): Gauges confidence in managing tasks and adhering to behavioral changes.

RESEARCH RESULTS

Overall Improvements:

‧ Significant improvements were observed in the intervention group on the ISI, PSQI, and DBAS-16 total scores.

‧ Key sleep parameters such as sleep onset latency, efficiency, and overall sleep duration improved markedly.

‧ Enhanced daytime functioning was also reported, reflecting better overall sleep quality.

Subscale Findings:

‧ Many subscales (e.g., subjective sleep quality, sleep duration) showed significant positive changes.

‧ However, subscales related to sleep medication use and medication-related beliefs did not change significantly—likely due to the exclusion of long-term medication users from the study.

Maintenance of Effects:

‧ Follow-up assessments at eight weeks post-intervention indicated that the improvements were maintained over time.

‧ The sustained benefits suggest that self-help CBT-I can offer durable improvements in sleep quality.

Dropout Analysis:

‧ Out of 85 participants, 63 completed the study while 21 dropped out.

‧ No significant differences were found between completers and dropouts in baseline sleep measures, although higher self-efficacy was linked with program completion.

‧ Common dropout reasons included the program’s perceived complexity and time demands rather than a lack of effectiveness.

DISCUSSION AND RECOMMENDATIONS

Efficacy and Advantages:

‧ The study demonstrates that self-help CBT-I can significantly improve sleep quality among shift workers, reducing insomnia severity and correcting dysfunctional sleep beliefs.

‧ Its online delivery makes the program accessible, cost-effective, and adaptable to the irregular schedules of shift workers.

‧ The use of automated feedback and sleep diaries aids in personalizing treatment and enhancing participant engagement.

Challenges and Future Directions:

‧ Adherence: High dropout rates indicate that simplifying initial modules and incorporating motivational supports may help improve adherence.

‧ Customization: Future programs could benefit from tailoring content to individual needs and addressing specific beliefs about sleep medication.

‧ Extended Follow-Up: Longer follow-up periods are recommended to assess the durability of treatment effects.

‧ Broader Application: Testing the intervention across different industries and regions could confirm its generalizability and identify potential limitations.

Concluding Remarks:

‧ The study demonstrates that a self-help CBT-I program is a promising, cost effective, and sustainable intervention for improving sleep quality among shift workers.

‧ With refinements to address adherence challenges and further customization of content, such programs have the potential for broader implementation in diverse work settings.

‧ Ultimately, this approach emphasizes the value of non-pharmacological treatments in managing chronic sleep disturbances associated with modern work patterns.