Objective Assessment of the Effects of Shift Work on Drowsiness and Driving Impairment in Hospital Staff

The purpose of this protocol is to assess the risk of drowsy driving amongst shift workers using objective measures of drowsiness and driving performance in an instrumented research vehicle.

Study Overview

• Status: Active, not recruiting
• Conditions: Impaired Driving; Sleep Driving

Detailed Description

Specific Aim 1. To test the hypothesis that on road (track) driving performance will deteriorate (variation in lateral lane position and the rate of out of lane driving events) and the frequency of episodes of severe sleepiness will increase ("microsleeps" on EEG and Johns' Drowsiness Score >4) in shift workers following an extended work shift or night shift compared to a rested state, following day shifts.

Specific Aim 2. To test the hypothesis that ocular measures of alertness (percent of time with eyes closed, eye tracking and Johns' Drowsiness Score) are related to abnormal driving performance (driving out of the lane) and "microsleeps" during on road (track) driving.

Specific Aim 2a. To test the hypothesis that autonomic measures, ECG, respiration (measured with the Bioharness), skin conductance level and peripheral blood flow (measured with the Q sensor), are related to abnormal driving performance (driving out of the lane) and "microsleeps" during on road (track) driving

Specific Aim 3. To test the hypothesis that self-reported sleepiness is related to on road (track) driving performance and episodes of severe sleepiness following extended working shifts or night shifts.

• Study Type: Observational
• Enrollment (Actual): 19

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Brigham and Women's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Participants in this study include shift workers who undertake extended duration shifts (16 hours or longer) or night shifts (e.g. resident physicians, nursing staff and allied health staff, police, firefighters, etc.).

Description

Inclusion Criteria:

• Participant must be a shift worker who undertakes extended duration shifts (16 hours or longer) or overnight shifts
• Participant must be between the ages of 18-65y
• Participant needs to have held a US driving license for two years previously or an International Driving license for two years with 6-months regular (>2/week) US driving experience
• Participants who wear corrective eye wear (i.e., glasses) are ONLY eligible to participate if they have a valid prescription so we can fit the Optalert glasses with their prescription lenses
• Resident physicians are only recruited if the combination of their time involvement in the study (i.e., any additional time beyond the time that it would ordinarily take them to commute home from work), together with their scheduled work hours, would fall within ACGME standards for duty hours for resident physicians.

Exclusion Criteria: Exclusion criteria includes all parameters outside the inclusion criteria above.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Brain activity including "microsleeps" using electroencephalography (EEG).	Continuous EEG recordings are made during each track driving session using a portable Vitaport 4 system (Temec ®).	Up to 3 hours per session for each participant.
Participants' fatigue and drowsiness level while driving using Optalert.	Optalert is a portable device, worn like sunglasses, designed to detect drowsiness, particularly when driving.	Up to 3 hours per session for each participant.
Driving performance measured by an instrumented vehicle.	A dual control instrumented vehicle, owned by Liberty Mutual, has been used for each driving session with each subject. This vehicle is fitted with a lane tracking system, as well as the capability to instruct and record responses from the driver. Lane position is monitored and recorded continuously with lateral and rear facing cameras. Data is logged to on-board computers.	Up to 3 hours per session for each participant.
Alertness level and level of fatigue measured by a composite of variables from a Zephyr Bioharness device worn by each participant.	The Zephyr Bioharness uses smart fabric sensors (non-adhesive) to measure electrocardiography (ecg), respiratory wave form, chest skin temperature, posture and activity (3-axis accelerometer).	Up to 3 hours per session for each participant.
Alertness level and level of fatigue from a composite of variables measured by an Affectiva Q-Sensor worn by each participant.	Additional autonomic nervous systems measures are obtained from a wrist-worn sensor (Affectiva Q-Sensor).	Up to 3 hours per session for each participant.
Participants' fatigue and drowsiness level measured by an eye tracker device.	An eye tracking device, owned by Liberty Mutual, is used to measure eye activity.	Up to 3 hours per session for each participant.
Participant's awareness of their fatigue level using a composite of survey data taken by each participant.	Questionnaires include: Karolinska Sleepiness Scale, Likelihood of Falling Asleep Questionnaire, and the Sleepiness Symptoms Questionnaire.	Surveys are taken by the participant every 15 minutes during regular stops during each session.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sleep and wake times using an Actiwatch device.	The Actiwatch-L recorder is a small wrist worn device (17 grams) that measures activity and ambient light exposure.	Up to 7 weeks per subject worn continuously during enrollment in the study.
Sleep and wake times using a 'sleep and work' diary completed by each subject.	Subjects maintain a sleep/work diary to provide a self-assessment of their sleep quantity and quality, work periods, as well as caffeine, medication, and alcohol intake.	Up to 7 weeks per participant completed daily.
Participants' view of their health and well-being using a composite of surveys administered during subject enrollment.	Participants are given the Berlin Apnea questionnaire, the MASLACH burnout inventory, and the Owl and Lark Questionnaire during enrollment. The data from these questionnaires will be used for analysis purposes.	Up to 2 hours per subject during the start of their participation in the study.

Collaborators and Investigators

• Sponsor: Brigham and Women's Hospital
• Collaborators: Institute for Breathing and Sleep, Australia; Liberty Mutual
• Investigators: Principal Investigator: Charles Czeisler, PH.D., M.D., Brigham and Women's Hospital

Study record dates

Study Major Dates

• Study Start: July 1, 2011
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: August 16, 2012
• First Submitted That Met QC Criteria: August 22, 2012
• First Posted (Estimated): August 27, 2012

Study Record Updates

• Last Update Posted (Actual): August 14, 2024
• Last Update Submitted That Met QC Criteria: August 13, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Keywords: sleep; Driving; EEG; questionnaire; survey; ECG; Diary; Optalert; impaired; Drowsy; Drive; Shift Work Disorder; SWD; Actiwatch; Bioharness; Q-Sensor; Q Sensor; Liberty Mutual; tracker; vehicle
• Additional Relevant MeSH Terms: Sleepiness
• Other Study ID Numbers: 2011P000370