Flotation restricted environmental stimulation therapy (REST) is not associated with long-term benefit to patients with chronic pain, according to research published in JAMA Network Open.
Flotation-REST has been demonstrated to produce a relaxation response, as well as lowered stress levels, improved sleep quality, reduced anxiety, and pain relief. Current studies, though, vary in study design. Researchers therefore conducted a single-blind, randomized clinical trial (Float4Pain; ClinicalTrials.gov identifier NCT03584750) to compare flotation-REST with placebo and wait-list control conditions in order to evaluate whether patients with chronic pain benefit from 5 consecutive flotation-REST settings.
Participants were randomly assigned to one of 3 groups and were informed that they would either receive 1 of 2 different kinds of flotation-REST treatments or would serve as wait-list controls. In both treatment groups, participants underwent five 60- to 90-minute treatment sessions.
The primary study outcome was change in both maximum and mean pain intensity assessed retrospectively for 1 week via a validated 101-point numerical rating scale (0-100). Secondary outcomes included pain-related disability, pain area, pain widespreadness, trait anxiety, depression, quality of life, sleep quality, and use of pain medication.
The cohort included 99 participants (mean age, 51.7±12.3 years; 81% women). Baseline characteristics were well-balanced across all 3 groups (intervention, n=32; placebo, n=37; control, n=30). Reported pain was generally moderate to severe pain (maximum, 73.9±16.3; mean, 50.1±17.3) and moderate levels of depression and trait anxiety.
No significant differences in credibility or expectancy were noted between the intervention and placebo groups, and no participants expressed doubts about the credibility of their received interventions.
No significant differences were noted in terms of the primary outcomes, with a -7.6 change in maximum pain in the intervention group, a -5.8 change in the placebo group, and a 0.4 change in the control group. Changes in mean pain were -2.1, -4.2, and 2.0 in each group, respectively. No differences in secondary long-term outcomes were noted among the 3 groups.
Patients in the intervention group demonstrated significant improvements in pain intensity, relaxation, anxiety, pain area, and Widespread Pain Index (WPI), with effect sizes ranging from medium to large. Small- to medium-sized effects were noted for heart rate and heart rate variability parameters. Similar changes were seen in the placebo group.
When comparing the placebo and intervention groups, investigators saw significant differences in terms of relaxation: More extensive improvements were noted in the placebo group. No differences were observed between sessions or in cumulative effects.
In the intervention and placebo groups, 64% and 52% experienced “unusual” bodily sensations that ranged from tingling and heaviness to out-of-body experiences.
Study limitations include the heterogeneity of pain symptoms; a lack of differentiation of comorbidities, triggering somatic events, or pain localization; and the potential influence of seasonal effects.
“To our knowledge, this is the first randomized, placebo-controlled clinical trial of flotation-REST in patients who have been diagnosed with chronic pain with somatic and psychological factors,” the researchers concluded.
“Our results show that these patients experienced no long-term benefits from the 5 treatment sessions. Significant improvements occurred in the short term, but they do not seem to be caused by environmental stimulus restriction or effortless floating, as previously thought.”
Loose LF, Manuel J, Karst M, Schmidt LK, Beissner F. Flotation restricted environmental stimulation therapy for chronic pain: a randomized clinical trial. JAMA Netw Open. 2021;4(5):e219627. doi:10.1001/jamanetworkopen.2021.9627