Improving Cancer-Related Outcomes in Shift Workers
Condition: Breast Cancer
MeSH terms: Breast Neoplasms
Study type: Interventional

Summary: 
      Shift work with circadian disruption has been linked with increased breast cancer incidence.
      The mechanisms for this effect are not yet completely understood.

      This study evaluates the impact of a previously developed sleep intervention in shift workers
      at risk of breast cancer; and assesses mediating variables that may explain the relationship
      between shift work and breast cancer.

      A sample of women night shift workers were provided with a sleep intervention. The
      intervention is a standard approach used in a sleep clinic and is delivered by telephone by a
      trained intervener.

      Hypothesis: The intervention will improve sleep in women night shift workers, which will in
      turn have a positive impact on biological and behavioural risk factors associated with breast
      cancer and quality of life.
    

Detailed description: 
      47 female night shift workers completed a sleep intervention. The intervention follows an
      established sleep therapy protocol. Assessments at baseline, 6 and 12 months include
      mammographic density and possible mediating variables known to be linked to breast cancer
      risk including behavioural, biometric, and biological measures. Behavioural and self-report
      measures of sleep quality and physical activity are assessed as well as self-reported
      chronotype and quality of life.

      The intervention is a multi-session intervention using cognitive behavioural principles to
      increase healthy sleep by addressing a variety of behaviours that may influence sleep quality
      and quantity, based an established telephone-based protocol used at the UBC Hospital Sleep
      Disorders Clinic. It includes 10 telephone sessions spaced over a 6-month period, and 2
      additional booster sessions at 8 and 10 months. Participants are given a sleep diary at
      baseline to complete for 2 weeks before the sleep hygiene telephone counseling session
      begins.

      The intervention protocol incorporates sleep assessment, maintaining a sleep diary and use of
      an actiwatch (to measure sleep and physical activity), sleep hygiene (i.e., controlling
      behavioural and environmental factors that affect sleep), stimulus control therapy (i.e.,
      teaching individuals how to eliminate behaviours that are incompatible with sleep), sleep
      restriction therapy (i.e., teaching how to limit time in bed to time asleep), cognitive
      restructuring (i.e., modifying non-adaptive thoughts and triggers for insomnia), and relapse
      prevention. The structured counseling protocol includes concrete exercises and activities,
      questions and answers, and problem solving strategies.

      Medication use is not part of this protocol; if participants wish to explore pharmacologic
      approaches, they are advised to consult with their physicians. Although some shift workers
      have received care from the Sleep Clinic in the past, there has not been a systematic focus
      on this group.

      The project manager conducts a telephone-based evaluation of the intervention 6 months
      post-sleep intervention. Blood and salivary samples are collected using standardized data
      collection methods at baseline, 6, and 12 months, and mammographic films are collected at
      baseline and 12 months.
    

Intervention name(s): Sleep intervention
Intervention type(s): Behavioral
Intervention description(s): Session 1: Intervener & participant review 2-week sleep diary and actigraph data. Provide individualized sleep hygiene prescription.
Session 2: Review sleep diary; calculate sleep efficiency; identify adjustments needed.
Session 3: Review sleep-related vs. stress-related symptoms. Develop plan for sleep-related symptoms and discuss "Sleep Restriction with Relaxation Exercises." Session 4: Reinforce progress and make corrections as required. If Sleep Restriction is not working, Stimulus Control is introduced.
Session 5-10: Provide reinforcement, assess adherence, answer questions, and offer encouragement and monitoring, including alterations as required.
Booster sessions: At 8 & 10 months: reinforcement, question answering, encouragement and monitoring.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: shiftwork; sleep hygiene; prevention; intervention; occupational; biological; breast cancer; lifestyle