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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Beneficial effects of treatment with sensory isolation in flotation-tank as a health-care intervention
Scientific title
Effects of treatment with sensory isolation in flotation-tank as a health-care intervention for healthy persons working full-time: effects on stress,energy, pain, anxiety, depression, sleep quality, mindfulness, and degree of altered states of consciousness
Secondary ID [1] 282403 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
stress 288984 0
pain 288985 0
general quality of life 288986 0
anxiety 288998 0
depression 288999 0
Condition category
Condition code
Alternative and Complementary Medicine 289327 289327 0 0
Other alternative and complementary medicine
Mental Health 289345 289345 0 0
Mental Health 289361 289361 0 0

Study type
Description of intervention(s) / exposure
The intervention is relaxation in a flotation tank. This tank is a device filled with magnesium sulphate (Epsom salt) saturated water (1.3 g/cm^3) heated to 35-36 degrees Celsius. In the tank there is darkness and silence. Ear-plugs are used.

The participants receive a total of twelve flotation sessions (each consisting of 45 minutes) during seven weeks. There is one session every 3-4 days over the 7 week intervention period. There is a session attendance monitoring at the floatation tank centre. If a participant do not arrive, or get sick, a new scheduled session is offered.
Intervention code [1] 287037 0
Other interventions
Comparator / control treatment
persons on waiting list for floatation tank is control group. They will be offered the interventions about 8 weeks later.
Control group

Primary outcome [1] 289437 0
depression < 6 HAD-scale
Timepoint [1] 289437 0
before and after 7 weeks
Primary outcome [2] 289438 0
anxiety < 6 HAD-scale
Timepoint [2] 289438 0
before and after 7 weeks
Primary outcome [3] 289439 0
stress SE-scale
Timepoint [3] 289439 0
before and after 7 weeks
Secondary outcome [1] 302474 0
energy SE-scale
Timepoint [1] 302474 0
before and after 7 weeks
Secondary outcome [2] 302475 0
pain, worst pain, normal pain VAS-scales.
Timepoint [2] 302475 0
before and after 7 weeks
Secondary outcome [3] 302476 0
degree of Mindfulness, MAAS-scale
Timepoint [3] 302476 0
before and after 7 weeks
Secondary outcome [4] 302477 0
optimism LOT-scale
Timepoint [4] 302477 0
before and after 7 weeks
Secondary outcome [5] 302478 0
sleep quality SQ-scale
Timepoint [5] 302478 0
before and after 7 weeks
Secondary outcome [6] 302479 0
experience of altered states of consciousness, EDN-scale (for experimental group only)
Timepoint [6] 302479 0
3 weeks, 7 weeks

Key inclusion criteria
interested in participating, working full time
Minimum age
18 Years
Maximum age
70 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
pregnancy, open wounds

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
An agreement was made between the owner of a flotation centre and three managers from three different companies about a health-care program involving flotation-tank treatments. All three companies advertised through intranet correspondence, their company magazines, and through emails, offering all employees to participate in the health-care program. All interested participants were invited to an information meeting at the flotation centre, where they were further informed about the program. Information was given that the flotation-rest program would enable them to participate in a scientific study concerning the effects of this treatment program. Further information was given regarding that the participation was voluntary, confidential, that they would be randomly selected to either experimental group or waiting list, and that they could terminate their participation at any given point. They were also informed it was possible to participate in the health-care program without participation in the present study.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
at the first meeting, the participant pulled a "lottery ticket" out of a closed box. It was written "floatation-tank" or "waiting list" on this ticket.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
MANOVA, repeated measure ANOVA.
From earlier studies with relaxation in flotation tank (flotation-REST) we know that for htese variables and the study design about 20 persons in each group is sufficient for an effect-size (Eta2) of 0,70 and p < 0.001, and a power of 0.98

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 5048 0
State/province [1] 5048 0

Funding & Sponsors
Funding source category [1] 287176 0
Self funded/Unfunded
Name [1] 287176 0
no funding
Address [1] 287176 0
no funding
Country [1] 287176 0
Primary sponsor type
Karlstad University
Karlstad University
Dept of Psychology
SE-651 88 Karlstad, Sweden
Secondary sponsor category [1] 285941 0
Name [1] 285941 0
Address [1] 285941 0
Country [1] 285941 0

Ethics approval
Ethics application status
Ethics committee name [1] 289172 0
Karlstad University Review board
Ethics committee address [1] 289172 0
Karlstad University
SE-651 88 Karlstad Sweden
Ethics committee country [1] 289172 0
Date submitted for ethics approval [1] 289172 0
Approval date [1] 289172 0
Ethics approval number [1] 289172 0

Brief summary
The purpose of this study was to evaluate effects in a series of 12 treatments (during 7 weeks) of flotation-REST in healthy participants, as a health-care intervention. Earlier research regarding flotation-REST mainly involves individuals with a diverse array of ailment, and so there is a need to further investigate this method when used by working professionals in order to find out if it is a suitable method for preventing stress and stress-related problems. We would like to know if healthy persons can have beneficial effects of this method. We know it is an efficient method for rehabilitation for persons on sick-leave, but we have never investigated it for healthy persons.

The local research ethical committee does not have anything to add on ethical grounds for the study "Beneficial effects of treatment with sensory isolation in flotation tank as a helath-care intervention" .
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 39594 0
Prof Anette Kjellgren
Address 39594 0
Karlstad University
Dept of Psychology
SE-651 88 Karlstad
Country 39594 0
Phone 39594 0
+46 54 700 21 73
Fax 39594 0
Email 39594 0
Contact person for public queries
Name 39595 0
Prof Anette Kjellgren
Address 39595 0
Karlstad University
Dept of Psychology
SE-651 88 Karlstad
Country 39595 0
Phone 39595 0
+46 54 700 21 73
Fax 39595 0
Email 39595 0
Contact person for scientific queries
Name 39596 0
Prof Anette Kjellgren
Address 39596 0
Karlstad University
Dept of Psychology
SE-651 88 Karlstad
Country 39596 0
Phone 39596 0
+46 54 700 21 73
Fax 39596 0
Email 39596 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary