Effects of Body Treatment on the Psychological and Physiological Well-Being of Care Workers

Last registered on July 22, 2026
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Pre-Trial

Trial Information

General Information

Title
Effects of Body Treatment on the Psychological and Physiological Well-Being of Care Workers
RCT ID
AEARCTR-0019158
Initial registration date
July 13, 2026

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
July 22, 2026, 7:51 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

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Primary Investigator

Name
Shinsuke Asakawa
Affiliation
Kagawa University
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Other Primary Investigator(s)

PI Name
Yuriko Matsunaga
PI Affiliation
Saga University
PI Name
Yumi Eto
PI Affiliation
Earth Inclusion

Additional Trial Information

Status
In development
Start date
2026-07-15
End date
2027-10-31
Keywords
Behavior, Health, Labor, Welfare
Additional Keywords
care workers; body treatment; socio-esthetic care; mental health; autonomic nervous system; heart rate variability; RCT; waitlist design; event-study; difference-in-differences
JEL code(s)
I12, J28, C93
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study is a randomized controlled trial that examines the causal effects of a non-medical body-treatment intervention (socio-esthetic care) on the psychological well-being, work-related attitudes, and autonomic nervous system activity of long-term care workers. The study plans to enroll up to 50 care workers from up to five long-term care facilities in Saga Prefecture, Japan. As of July 2026, 35 care workers have been recruited from three participating facilities. Participants are assigned, via block randomization stratified by facility, to either an early-intervention group (treated during the first half of the study period) or a waitlist group (treated during the second half), following a waitlist-controlled randomized design.

The intervention consists of three non-medical body-treatment sessions, each lasting approximately 30 minutes and delivered by certified socio-estheticians. The primary estimand is the average treatment effect on the treated (ATT). Using a seven-round questionnaire panel, including baseline, the study employs an event-study difference-in-differences design to estimate treatment effects at each survey round.

The primary outcome is a Mental Health Index, constructed as the standardized composite of four validated scales: anxiety (GAD-7), depression (PHQ-9), burnout (the Japanese Burnout Scale), and psychological stress reactions (the Brief Job Stress Questionnaire, BJSQ). Secondary outcomes include job satisfaction, occupational continuation intention, workplace retention intention, career orientation, and heart rate variability (RMSSD and the LF/HF ratio), which are analyzed as physiological mechanisms.

The study aims to provide policy-relevant evidence on whether a feasible, non-medical intervention can improve the psychological well-being, physiological stress responses, and work-related outcomes of long-term care workers.
External Link(s)

Registration Citation

Citation
Asakawa, Shinsuke, Yumi Eto and Yuriko Matsunaga. 2026. "Effects of Body Treatment on the Psychological and Physiological Well-Being of Care Workers." AEA RCT Registry. July 22. https://doi.org/10.1257/rct.19158-1.0
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Experimental Details

Interventions

Intervention(s)
Participants receive three non-medical body-treatment sessions (approximately 30 minutes per session) delivered by certified socio-estheticians. Treatment consists of either oil-based or dry-touch body care designed to promote relaxation and psychological well-being. Participants assigned to the early-intervention group receive treatment during the first half of the study period, while participants assigned to the waitlist group receive the same intervention during the second half.
Intervention Start Date
2026-07-15
Intervention End Date
2027-05-26

Primary Outcomes

Primary Outcomes (end points)
Mental Health Index (primary endpoint): a standardized composite index constructed from four validated scales: GAD-7 (anxiety), PHQ-9 (depression), the Japanese Burnout Scale (JBS), and the psychological stress reaction subscale of the Brief Job Stress Questionnaire (BJSQ). Higher values indicate poorer mental health.

The four component scales (GAD-7, PHQ-9, JBS, and BJSQ psychological stress reaction) are also analyzed individually as primary outcomes.
Primary Outcomes (explanation)
The Mental Health Index is calculated as the unweighted average of standardized (z-scored) values of GAD-7, PHQ-9, JBS, and the BJSQ psychological stress reaction subscale. Standardization uses the baseline mean and standard deviation of the waitlist group. All measures are coded so that higher values indicate poorer mental health.

Secondary Outcomes

Secondary Outcomes (end points)
* Job satisfaction
* Occupational continuation intention
* Workplace retention intention
* Career orientation
* Heart rate variability (RMSSD and LF/HF ratio) measured during treatment sessions as a physiological mechanism
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
This study is a waitlist-controlled randomized controlled trial conducted among up to 50 long-term care workers from up to five long-term care facilities in Saga Prefecture, Japan. As of July 2026, 35 participants have been recruited from three participating facilities.

Within each facility, participants are randomly assigned by block randomization to either an early-intervention group or a waitlist group. The early-intervention group receives three body-treatment sessions during the first half of the study period, while the waitlist group receives the same intervention during the second half.

Questionnaire outcomes are collected over seven survey rounds, including baseline. The primary analysis uses an event-study difference-in-differences model with individual and survey-round fixed effects to estimate treatment effects over time. Heart rate variability is analyzed as a physiological mechanism of the intervention.
Experimental Design Details
Not available
Randomization Method
Computer-generated block randomization stratified by facility, conducted by the principal investigator using randomization software.
Randomization Unit
Individual participant (within each participating facility).
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
Up to 5 long-term care facilities (3 facilities participating as of July 2026).
Sample size: planned number of observations
Up to 50 participants (35 recruited from 3 facilities as of July 2026), corresponding to approximately 350 participant-round questionnaire observations (up to 50 × 7 survey rounds) and up to 150 HRV treatment sessions (up to 50 × 3 sessions).
Sample size (or number of clusters) by treatment arms
Up to 25 participants were assigned to the early-intervention group, and up to 25 participants were assigned to the waitlist group through block randomization stratified by facility. The final numbers may vary depending on recruitment and attrition.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Kagawa University Faculty of Economics Research Ethics Committee
IRB Approval Date
2026-06-30
IRB Approval Number
2026_02_01
Analysis Plan

Analysis Plan Documents

Pre analysis plan

MD5: e2268e5f1ee1273756fe7f197d1f51aa

SHA1: 33b96f62ad6b1e01b116d65767c65c2f769b50f2

Uploaded At: July 13, 2026