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Trial registered on ANZCTR


Registration number
ACTRN12617001486314
Ethics application status
Approved
Date submitted
10/10/2017
Date registered
20/10/2017
Date last updated
24/10/2019
Date data sharing statement initially provided
24/10/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
Can consuming caffeine after a nap improve productivity, alertness and safety?
Scientific title
Combining nap and caffeine countermeasures to improve productivity, alertness and safety in healthy adults undergoing a simulated nightshift
Secondary ID [1] 293103 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Shiftwork 305046 0
Sleep inertia 305047 0
Sleep deprivation 305048 0
Condition category
Condition code
Other 304371 304371 0 0
Research that is not of generic health relevance and not applicable to specific health categories listed above

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will undergo two 37h in laboratory sleep deprivation protocols. Participants will enter the laboratory at 11am on day 1; stay awake all night; and then sleep between 12pm and 6pm on day 2. Participants will remain in the lab until 12am.

Participants will undergo 2 conditions, with the order of conditions randomised: 1) 30min nap with 200mg caffeine gum on waking; and 2) a 30min nap with placebo gum. The 30min nap will be allowed between 2 to 2:30am.

They will visit the laboratory twice, a week apart, in a within groups, repeated measures design. Each person will be their own control.

A 30 minute cognitive performance test battery, consisting of a 10 minute Psychomotor Vigilance Task, Karolinska Sleepiness Scale, Positive and Negative Affect Schedule, and mood Visual Analogue Scales will be administered at 8:30pm and 11pm on day 1 and at 1am, 5am, 9am, and 8:30pm on day 2. A 20 minute learning reversal decision task will be performed at 9pm on day 1 and 7:30am and 8:30pm on day 2. This computerised task is based on a go/no go paradigm. Initially four two-digit numbers are assigned to the go (response) set and four two-digit numbers are assigned to the no go (no response) set. Participants have a 750ms window to either respond or withhold a response to the number displayed on the screen. A hypothetical money reward/punishment is displayed to allow participants to determine which numbers are in the go set and which are in the no go set. After a number of trials (56, 60, or 64) the response sets are reversed for another 40 trials. A 40 minute driving simulation task (Yorke Driving Simulator) will be conducted at 7:30pm on day 1 and 6:30am, 10am, and 7:30pm on day 2. A sleep inertia test battery will be conducted post nap starting at 2:30am.

Sleep inertia testing will consist of a 3 minute Psychomotor Vigilance Task, Karolinska Sleepiness Scale, and mood Visual Analogue Scales, and performed every 10 minutes (4 sleep inertia tests to map performance in the hour post nap).

Venous blood sampling will be at 12:30pm on day 1 and 3:15am, 4:10am, 5:40am, and 11am on day 2 to quantify plasma caffeine concentrations for pharmacokinetic assessment, the impact of the caffeine gum on cortisol as a marker of stress and the impact of the caffeine gum on melatonin sectretion. Hourly saliva sampling will used to measure melatonin levels during wake periods.

Data will be analysed using mixed models and pharmacokinetic/pharmacodynamics modelling will be used to investigate the relationship between blood (plasma) caffeine concentrations and various indices of sleep inertia.
Intervention code [1] 299348 0
Treatment: Drugs
Comparator / control treatment
Placebo
Control group
Placebo

Outcomes
Primary outcome [1] 303620 0
Shift in melatonin onset as measured in saliva using radioimmunoassay
Timepoint [1] 303620 0
Saliva will be collected hourly from 1800 to 0000 prior to caffeine administration and collected hourly from 1800 to 0000 post caffeine administration
Primary outcome [2] 303621 0
3 minute Psychomotor Vigilance Task
Timepoint [2] 303621 0
5 minutes, 15 minutes, 25 minutes, and 35 minutes post caffeine administration
Secondary outcome [1] 339655 0
Change in melatonin secretion profile measured in plasma using radioimmunoassay
Timepoint [1] 339655 0
0,75 hours, 1.75 hours, and 3.25 hours post caffeine administration
Secondary outcome [2] 339657 0
Neurobehavioural Test Battery (10 minute Psychomotor Vigilance Task, Karolinska Sleepiness Scale, Positive and Negative Affect Scale, Visual Analogue Scales of mood)
Timepoint [2] 339657 0
2.5 hours, 6.5 hours, and 18 hours post caffeine administration
Secondary outcome [3] 339658 0
A 20 minute learning reversal decision task (Go/No Go)
Timepoint [3] 339658 0
5 hours and 18 hours post caffeine administration
Secondary outcome [4] 339659 0
40 Minute driving simulator task using the Yorke Driving Simulator
Timepoint [4] 339659 0
4 hours, 7.5 hours, and 17 hours post caffeine administration

Eligibility
Key inclusion criteria
BMI between 18.5-29 kg/m2
Habitual bedtime between 2100h and 2400h
Habitual wake time between 0600h and 0900h
Less than 2 hours of structured high impact activity per week
Currently taking a contraceptive pill or experiencing regular menstrual cycles (females)
Valid driver’s licence or sufficient driving experience
Minimum age
18 Years
Maximum age
40 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
History of smoking, drug, or alcohol abuse in the past year
History of psychiatric illness or sleep disorders such as insomnia and sleep apnoea
Food allergies
Trans-meridian travel in the 30 days prior to the study commencing
Clinically significant abnormalities in blood and urine
Shiftwork
Habitual napping
Caffeine intake exceeding 400mg per day on average
Score <22 or >44 on the Composite Morningness Questionnaire
Score >14 on the Beck Depression Index
Score >5 on the Pittsburgh Sleep Quality Index
History of cardiovascular disease
History of a neurological disorder
Pulmonary disease requiring daily inhaler use
Kidney disease
Liver disease
History of psychiatric disorder requiring hospitalisation or psychiatric product for any length of time
Positive urine pregnancy result
Resting blood pressure above 140/90
Resting pulse >110

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using procedures like coin-tossing and dice-rolling

Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
Intervention assignment
Crossover
Other design features
Phase
Phase 4
Type of endpoint(s)
Efficacy
Statistical methods / analysis
This is a pilot study. The results will be used to determine the number of participants needed to achieve the objectives of future studies.

Mixed Model Analysis of Variance (ANOVA) will be employed, including a random factor for subjects and fixed repeated-measures effects for caffeine group and test session. A fixed between-subjects (grouping) factor also will be included. Other analytical procedures (e.g. regression and/or discontinuous growth modelling) may be used to further evaluate interactive effects of caffeine vs placebo, naps and sleep loss.

Recruitment
Recruitment status
Recruiting
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)
SA

Funding & Sponsors
Funding source category [1] 297731 0
University
Name [1] 297731 0
University of South Australia
Address [1] 297731 0
Level 1
101 Currie Street
Adelaide SA 5000
GPO Box 2471
Adelaide SA 5001
Country [1] 297731 0
Australia
Primary sponsor type
Individual
Name
Assoc Prof Siobhan Banks
Address
University of South Australia
Magill Campus
Sleep and Chronobiology Laboratory
St Bernards Rd
Magill, SA 5072
Country
Australia
Secondary sponsor category [1] 296758 0
Individual
Name [1] 296758 0
Assoc Prof Jill Dorrian
Address [1] 296758 0
University of South Australia
Magill Campus
Sleep and Chronobiology Laboratory
St Bernards Rd
Magill, SA, 5072
Australia
Country [1] 296758 0
Australia
Secondary sponsor category [2] 296760 0
Individual
Name [2] 296760 0
Assoc Prof Alison Coates
Address [2] 296760 0
University of South Australia
City East Campus
School of Health Sciences
Frome Road
Adelaide, SA 5000
Country [2] 296760 0
Australia
Secondary sponsor category [3] 296761 0
Individual
Name [3] 296761 0
Dr Stephanie Reuter Lange
Address [3] 296761 0
University of South Australia
City East Campus
School of Pharmacy and Medical Sciences
Frome Road
Adelaide, SA 5000
Country [3] 296761 0
Australia
Secondary sponsor category [4] 296762 0
Individual
Name [4] 296762 0
Prof Allan Evans
Address [4] 296762 0
University of South Australia
City West Campus
Provost and Chief Academic Officer Chancellery and Council Services
North Tce
Adelaide, SA 5000
Country [4] 296762 0
Australia
Secondary sponsor category [5] 296763 0
Individual
Name [5] 296763 0
Prof Kurt Lushington
Address [5] 296763 0
Head of School
University of South Australia
Magill Campus
Psychology, Social Work and Social Policy
St Bernards Rd
Magill, SA, 5072
Australia
Country [5] 296763 0
Australia
Secondary sponsor category [6] 296764 0
Individual
Name [6] 296764 0
Antonietta Colella
Address [6] 296764 0
Industry Engagement Adviser
Safework SA
4/33 Richmond Rd
Keswick SA 5035
Country [6] 296764 0
Australia
Secondary sponsor category [7] 296765 0
Individual
Name [7] 296765 0
Mercedes Iasiello
Address [7] 296765 0
Principal WHS Strategy and Policy Consultant, Strategy Policy and Performance
SA Health
Citi Centre Building
11 Hindmarsh Square
Adelaide SA 5000
Country [7] 296765 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 298797 0
University of South Australia’s Human Research Ethics Committee
Ethics committee address [1] 298797 0
University of South Australia
Magill Campus
St Bernards Rd
Magill, SA, 5072
Ethics committee country [1] 298797 0
Australia
Date submitted for ethics approval [1] 298797 0
Approval date [1] 298797 0
17/12/2016
Ethics approval number [1] 298797 0
0000036014

Summary
Brief summary
Fatigue causes a deterioration in cognitive performance that leads to workplace errors, injury and reduced safety. Shift work is a major source of fatigue because it disrupts the timing and duration of sleep opportunities; and therefore night workers are often chronically sleep deprived. Our work shows that 30min naps can be a powerful tool for maintaining performance during conditions of sleep deprivation. Naps can be particularly beneficial for night workers, who are on duty at times when their body rhythms naturally prime them to be asleep. However, napping can also be hazardous. Our studies show that it can have deleterious effects, in particular, `sleep inertia’, the groggy feeling and performance impairment experienced after waking where workers are extremely vulnerable to errors. This is problematic for oncall workers or health care professionals who take naps during extended hours or night shifts, but on waking need to process complex information, or engage in safety critical activities. Our recent systematic review found very few studies have investigated countermeasures that that can be implemented immediately on waking to reduce sleep inertia. Our work with caffeine gum, funded by USA and Australian Army has found it is fast acting (i.e. within 5min). It could therefore be the ideal countermeasure for the sleep inertia associated with night time naps.

This study aims to answer two questions:
1. Will 200mg of caffeine (given in gum form) administered upon waking from a 30 min nap at 2:30am prevent sleep inertia when compared to placebo?
2. Will 200mg of caffeine (given in gum form) administered upon waking from a 30 min nap at 2:30am impact daytime recovery sleep between 12 and 6pm?
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 78254 0
A/Prof Siobhan Banks
Address 78254 0
University of South Australia
Magill Campus
Sleep and Chronobiology Laboratory
St Bernards Rd
Magill, SA, 5072
Country 78254 0
Australia
Phone 78254 0
+618 8302 1712
Fax 78254 0
Email 78254 0
Siobhan.banks@unisa.edu.au
Contact person for public queries
Name 78255 0
Ms Jackie Stepien-Hulleman
Address 78255 0
University of South Australia
Magill Campus
Sleep and Chronobiology Laboratory
St Bernards Rd
Magill, SA, 5072
Australia
Country 78255 0
Australia
Phone 78255 0
+618 8302 1970
Fax 78255 0
Email 78255 0
Jacqueline.stepien-hulleman@mymail.unisa.edu.au
Contact person for scientific queries
Name 78256 0
Ms Jackie Stepien-Hulleman
Address 78256 0
University of South Australia
Magill Campus
Sleep and Chronobiology Laboratory
St Bernards Rd
Magill, SA, 5072
Australia
Country 78256 0
Australia
Phone 78256 0
+618 8302 1970
Fax 78256 0
Email 78256 0
Jacqueline.stepien-hulleman@mymail.unisa.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
We do not have ethics approval to share individual participant data with any entity outside of the research group. All analyses will be done by the research group only.
What supporting documents are/will be available?
No other documents available
Summary results
No Results