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Trial registered on ANZCTR


Registration number
ACTRN12616001636448
Ethics application status
Approved
Date submitted
7/03/2016
Date registered
25/11/2016
Date last updated
23/01/2019
Date data sharing statement initially provided
23/01/2019
Date results information initially provided
23/01/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
Reducing the risk of cardiovascular disease in nurses who work night shift
Scientific title
The effectiveness of a physical activity intervention in nurses working night shift
Secondary ID [1] 288700 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Endothelial function 297918 0
Cardiovascular disease 297919 0
Physical inactivity 297938 0
Condition category
Condition code
Cardiovascular 298084 298084 0 0
Coronary heart disease
Public Health 298085 298085 0 0
Health promotion/education

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
All nurses, irrespective of rank, will be eligible to participate. We are aiming to recruit 120 nurses (n= 60 day shift and n=60 night/rotating shift) for Phase 1, which is a cross-sectional study comparing vascular function, physical activity and risk for CVD in nurses who work day shift with those who work night / rotating shifts.

Phase 2 is a randomized control trial to assess the effectiveness of a physical activity intervention. Nurses who work night/rotational shifts and are inactive (<150 minutes per week) will be invited to participate in Phase 2. Randomisation will take place at the ward level, to ensure that nurses in the same ward are allocated to the same group, either the intervention or control group, as this will prevent contamination between participants.

Data obtained in Phase 1 will serve as the baseline or pre-intervention measures for the night shift nurses' intervention study. All participants (day and night/rotating shift workers) will have Baseline vascular function assessments the morning of a day shift (no night shift previous day). All other clinical measures and self-reported lifestyle data will also be collected during this first visit. Follow-up measurements of vascular function will be conducted only in the night/rotational shift nurses, and will take place the morning after a night shift after the 8 week intervention.

Phase 2 is an 8-week intervention for night/rotational shift workers who are insufficiently physically active. Endothelial function will be re-assessed at 2 and 8 weeks following the start of the intervention. Physical activity, clinical measures and components of the survey will be repeated at 8 weeks. The primary outcome measure in this phase is changes in endothelial function (FMD). The secondary outcomes include changes in physical activity, sedentary behaviour, Body Mass Index, blood pressure and cardiovascular disease risk score.

Measurements:
Primary Outcome measure: Vascular Function
Peripheral endothelial function: Nurses will rest in the supine position for 20 minutes after which a pneumatic cuff will be inflated for 5 minutes. Brachial artery diameters and flow measures will start 30 seconds prior to deflating the cuff, until 3 minutes after deflation. The time taken to reach maximum post-deflation diameter will also be recorded as ‘time to peak’.
Secondary Outcome Measures:
Objective measure of Physical Activity: Physical activity will be measured objectively using the Actigraph GT3X (ActiGraph, Shalimar, FL, USA) accelerometer.
Clinical Measures: Blood pressure and a fasting blood sample will be taken to measure serum glucose concentration, HDL, LDL and triglycerides. Height and weight will be measured to calculate Body Mass Index, and waist circumference will be measured using standard protocols.
Australian absolute cardiovascular disease risk score (AACDRS): The participants will be asked to complete a survey with questions about: demographic information (age, education, years working shifts), lifestyle behaviours (dietary habits and smoking status) and self-reported health status. These data, together with the clinical measures, will be used to calculate the AACDRS.

Intervention: The 8-week multi-component intervention will comprise a one-on-one information session (10-15 minutes) during which a research assistant will provide participants with their baseline results and set physical activity goals. The nurses will also receive an educational booklet and self-monitoring physical activity device (Fitbit Flex) to track physical activity. The educational booklet will include information on the benefits of pf physical activity, the importance of sleep, and chronotype. They will be encouraged to wear the FitBit and engage in 30-60 minutes of moderate intensity physical activity every day and to log onto a website to track progress. The shift workers in the wait list control group will receive the educational booklet only, and will be offered the opportunity to participate in the intervention at the end of the 8 weeks. All nurses in the study will receive a certificate from LCCH/UQ endorsing their participation as eligible for their annual mandatory continuing professional development required by Australian Health Practitioner Regulating Authority (AHPRA).
Intervention code [1] 294125 0
Behaviour
Intervention code [2] 294137 0
Lifestyle
Intervention code [3] 294138 0
Treatment: Other
Comparator / control treatment
The shift workers in the control group will also meet with the research assistant (exercise physiologist) for approximatley 30 minutes, to receive feedback on their baseline results and receive the educational leaflet. These participants will not receive the Fitbit flex to monitor physical activity, and will not receive any encouragement to change their physical activity behaviour.
Control group
Active

Outcomes
Primary outcome [1] 297598 0
Vascular function:
Nurses will rest in the supine position for 20 minutes after which a pneumatic cuff will be inflated for 5 minutes. Brachial artery diameters and flow measures will start 30 seconds prior to deflating the cuff, until 3 minutes after deflation. The time taken to reach maximum post-deflation diameter will also be recorded as ‘time to peak’. The double lines of Pignoli on the carotid artery will be used to quantify inter-medial thickness. The terason ultrasound machine will be used to measure flow mediated dilitation.
Timepoint [1] 297598 0
Baseline
2-weeks (intervention group only)
8-weeks
Secondary outcome [1] 321550 0
Physical activity
Physical activity will be measured objectively using the waist-worn Actigraph GT3X (ActiGraph, Pensacola, FL, USA) accelerometer. The Actigraph GT3X is a small, light-weight device that uses a tri-axial accelerometer to collect motion data. The GT3X has a 16MB storage capacity, a pedometer (step counter) function and an inclinometer to determine body position. The monitors will be initialised to collect data in 60-second epochs.

Monitors will be worn with an adjustable belt at hip level, in line with the mid-line of the thigh, for 7 consecutive days, to measure steps per day. In addition, time spent in sedentary, light, moderate and vigorous intensity physical activity will be calculated from cut-points previously described by Troiano et al using Actilife software (Actigraph, FL, USA).
Timepoint [1] 321550 0
Baseline
8 weeks
Secondary outcome [2] 321551 0
Blood pressure
Systolic and diastolic blood pressure will be measured twice per person using an automated sphygmomanometer. The nurses will be instructed to sit quietly for approximately three minutes before being measured. Both readings will be recorded and the average of the two will be used in the statistical analysis.
Timepoint [2] 321551 0
Baseline
8-weeks
Secondary outcome [3] 321552 0
Body Mass Index
Standing height (cm) will be measured to the nearest 0.1 cm, using a stadiometer. Body weight will be measured using a portable calibrated scale and recorded to the nearest 0.1 kg. The nurses will be asked to remove shoes, jackets / jumpers / jerseys and asked to empty pockets for these measurements. Body Mass Index (BMI) will be calculated as body mass (kg) divided by height (m) squared (kg/m2).
Timepoint [3] 321552 0
Baseline
8-weeks
Secondary outcome [4] 321553 0
Chronotype
The Horne-Ostberg Morning-Evening Personality Questionnaire will be used to measure self-reported. This questionnaire will be used to measure self-reported diurnal preference or chrono-type. It comprises 19 questions related to time of waking, how refreshed participants feel on waking and whether they use an alarm clock to wake up. Low scores (16-41) indicate eveningness and high scores (59-86) indicate morningness. Based on the scores obtained, individuals are placed into one of five chronotype categories. Thus the outcome variables will be (i) chronotype score and (ii) chronotype category: definite evening-type (score 16-30), moderate evening-type (31-41), neither-type (42-58), moderate morning-type (59-69), and definite morning-type (70-86). This measure will help us to determine how chrono-type might influence lifestyle behaviours, especially for nurses who work night or rotational shifts. We will add two additional questions to determine the time nurses usually go to bed and wake up on a day shift, night shift and their days off.
Timepoint [4] 321553 0
Baseline
Secondary outcome [5] 329620 0
Waist circumference
Waist circumference (cm) will be measured immediately above the iliac crest.
Timepoint [5] 329620 0
baseline
8 weeks

Eligibility
Key inclusion criteria
all nurses, irresepective of rank will be invited to participate in Phase 1.
Only night shift nurses who have less than 150 minutes of physical activity per week, will be invited to participate in Phase 2.
Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Nurses with known or uncontrolled cardiovascular and metabolic disease.

Study design
Purpose of the study
Prevention
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
There will be no concealment,
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
QLD
Recruitment hospital [1] 5397 0
Lady Cilento Children's Hospital - South Brisbane

Funding & Sponsors
Funding source category [1] 293059 0
University
Name [1] 293059 0
University of Queensland
Address [1] 293059 0
School of Human Movement and Nutrition Studies
Level 5, Building 26 (B)
Blair Drive
St Lucia, Brisbane
4072
Queensland
Country [1] 293059 0
Australia
Primary sponsor type
University
Name
University of Queensland
Address
School of Human Movement and Nutrition Studies
Level 5, Building 26 (B)
Blair Drive
St Lucia, Brisbane
4072
Queensland
Country
Australia
Secondary sponsor category [1] 291838 0
None
Name [1] 291838 0
none
Address [1] 291838 0
Country [1] 291838 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 294568 0
Children's Health Queensland Hospital and Health Service Human Research Ethics Committee
Ethics committee address [1] 294568 0
Centre for Children's Health Research
LCCH
62 Graham Street
South Brisbane
4101
Queensland
Ethics committee country [1] 294568 0
Australia
Date submitted for ethics approval [1] 294568 0
07/03/2016
Approval date [1] 294568 0
22/03/2016
Ethics approval number [1] 294568 0
HREC/16/QRCH/52

Summary
Brief summary
Most nurses work shifts, and those who work night shifts have poorer lifestyle behaviours than those who work day shift only, placing them at increased risk of cardiovascular disease (CVD) and diabetes. There is strong evidence to show that shift workers have a 40% higher risk of CVD than non-shift workers. Regular physical activity (PA) is associated with reduced risk of CVD and has been shown to improve vascular function. However, shift workers have less opportunity to participate in leisure time PA and have poorer health seeking behaviours than non-shift workers.

This research will investigate the impact of physical activity (PA) on intermediary vascular function and CVD outcomes in nurses who work night or rotational shifts. This will be achieved by: (1) measuring current PA patterns and vascular function, and comparing these in nurses who work night or rotating shifts with those who only work day shift; (2) conducting a feasibility trial of a PA intervention program for nurses who work night/rotational shifts. We hypothesise that participants in the intervention group will have increased levels of PA, significantly greater improvements in vascular function, and reduced risk of CVD compared with those in the control group.

Intervention and comparison groups:
Nurses who work night/rotational shifts and who participate in less than 150 minutes of physical activity per week, will be invited to participate in the intervention.

The 8-week intervention will comprise a one-on-one information session during which a research assistant will provide participants with feedback for their baseline results and set physical activity goals. The nurses will also receive an educational leaflet and self-monitoring device (Fitbit Flex) to track physical activity.

The shift workers in the control group will also meet with the research assistant (exercise physiologist) to receive feedback on their baseline results and receive the educational leaflet. These participants will not receive the Fitbit flex to monitor physical activity, and will not receive any encouragement to change their physical activity behaviour.

Outcome Measures:
The main outcome measure is a change in vascular function (assessed using ultrasound) and physical activity (assesed using acelerometers). Secondary outcomes include change in sedentary behaviour, cardiovascular disease risk score and Body Mass Index.

These measurements will take place at baseline (Phase 1) and then at 2 (vascular function only) and 8 weeks in the intervention group. The comparison group will have measurements performed at baseline and 8 weeks.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 64186 0
Dr Tracy Kolbe-Alexander
Address 64186 0
School of Human Movement and Nutrition Sciences
University of Queensland
Building 26 (b)
Blair Drive
St Lucia
4072, Queenland
Country 64186 0
Australia
Phone 64186 0
+61 07 3812 6178
Fax 64186 0
Email 64186 0
tracy.kolbe-alexander@usq.edu.au
Contact person for public queries
Name 64187 0
Dr Tracy Kolbe-Alexander
Address 64187 0
School of Health and Well-being
University of Southern Queensland
Salisbury Road
Ipswich
Queensland
Australia
Country 64187 0
Australia
Phone 64187 0
+61 7 3812 6178
Fax 64187 0
Email 64187 0
t.kolbealexander@uq.edu.au
Contact person for scientific queries
Name 64188 0
Dr Tracy Kolbe-Alexander
Address 64188 0
School of Health and Well-being
University of Southern Queensland
Salisbury Road
Ipswich
Queensland
Australia
Country 64188 0
Australia
Phone 64188 0
+6 17 3812 6178
Fax 64188 0
Email 64188 0
tracy.kolbe-alexander@usq.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
The individual data will be available to the researchers only.
De-Identified data can be made available on request, when publishing research
What supporting documents are/will be available?
Study protocol
Statistical analysis plan
Informed consent form
Ethical approval
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
No
Results – basic reporting
Results – plain English summary