Science

Science

Explore WELT’s research findings, publications, regulatory authorizations and quality systems.

Clinical studies

Explore the study population, comparator and outcome measures.

SleepQ® · Clinical evidence

Sleep efficiency improved by 15.14 percentage points after six weeks

Peer-reviewed
Participants
Adults with insomnia
Comparator
Sham software
Assessment
Six weeks of treatment; week-seven assessment

Improvement in sleep efficiency from baseline

SleepQ®15.14pp
Sham software control6.86pp
Adjusted improvement from baseline15.14pp

With the same eight hours in bed

Sleep efficiency: 60% → 75.14%

About 4 hours 50 minutesAbout 6 hours

Illustrative conversion assuming unchanged time in bed; not a prediction of individual treatment results.

Study design and interpretation
Measure interpretation
Sleep efficiency is the proportion of time in bed spent asleep. Bars show adjusted changes from baseline in percentage points (pp).
Units
A percentage point (pp) is the unit used for the difference between two percentages.
Between-group comparison
Improvement was 8.28 percentage points greater with SleepQ® than with sham software. p = 0.0418.
Illustrative calculation
480 minutes in bed × 0.1514 = 72.672 minutes. This assumes sleep efficiency changes from 60% to 75.14%; it is not the observed change in participants’ sleep duration.
Design
Double-blind, sham-controlled randomized trial / Severance Hospital
Population
68 randomized; efficacy analysis of 54 (SleepQ® 28, control 26)
Assessment
After six weeks of treatment; seven weeks including assessment
Statistics
Difference 8.28 percentage points; 95% CI 0.32–16.24; effect size d = 0.68
Safety
Eight mild adverse events were reported. No device-related or serious adverse events were reported.
SerenQ® · Clinical evidence

66% reduction in binge-eating frequency at eight weeks

Authorization trial
Participants
Patients with eating disorders
Comparator
In-person psychiatric care every two weeks
Assessment
Week eight

Reduction in binge-eating frequency after eight weeks

SerenQ®66%
In-person care43%
Between-group difference23pp

SerenQ® reduced binge-eating frequency by 23 percentage points more than the in-person care group.

p = 0.0031
Study design and interpretation
Measure interpretation
These percentages describe changes in episode frequency, not cure or responder rates.
Units
A percentage point (pp) is the unit used for the difference between two percentages.
Design
Multicenter randomized trial at Seoul National University Hospital and Severance Hospital
Comparator
In-person psychiatric care every two weeks over eight weeks
Program and assessment
Eight-session treatment program; main outcome assessed at week eight
Long-term follow-up
Improvement within the SerenQ® group was observed at 12 months. The between-group difference in binge-eating frequency was not statistically significant (p = 0.156).
Evidence status
Company clinical-trial summary; authorization-trial publication in preparation

Source: WELT trial summaries (WCTP-ED-B-01 and WCTP-ED-D-01), September 2026. Results apply to the studied conditions.

SerenQ® · BMI ≥25 subgroup analysis

A larger reduction in binge eating
in the BMI ≥25 subgroup

Observed changes in binge-eating frequency after eight weeks of SerenQ® treatment.

Overall treatment groupSerenQ®
66%
Higher-BMI subgroupBMI ≥25
76%

Building on this eating-behavior expertise, WELT is pursuing expansion into obesity and metabolic care.

Subgroup interpretation

The BMI ≥25 subgroup is included in the overall treatment group. The 66% and 76% values describe observed reductions; they are not a comparison of independent trial arms or confirmation that treatment efficacy differs by obesity status.

Within the BMI ≥25 subgroup, binge-eating frequency decreased by 76.0% with SerenQ® and 36.9% with in-person care at eight weeks—a difference of 39.1 percentage points.

These are reductions in binge-eating frequency, not body weight or BMI. Current authorization covers improvement of binge-eating symptoms in patients with eating disorders. These subgroup findings from the company clinical trial summary do not demonstrate weight loss or establish authorization for obesity treatment.

RWE · Routine clinical care

Improvement in insomnia symptoms
in routine clinical care

An RWE analysis of patients prescribed SleepQ® estimated an average 6.59-point reduction in the Insomnia Severity Index (ISI) from before to after treatment.

37

Participating hospitals

−6.59 points

Average ISI change from before treatment

What this measure means

The ISI is a questionnaire that measures insomnia symptom severity. Lower scores indicate less severe symptoms, so a lower average score reflects improvement.

WELT-REST

Expanding SleepQ® evidence in Germany

The WELT-REST study with Charité Berlin has completed patient follow-up and is analyzing results. It compares SleepQ® plus usual care with usual care alone, assessing the Insomnia Severity Index at 12 weeks.

Target enrollment: 82. First patient enrolled in December 2025; patient follow-up complete and results analysis underway as of September 2026. DiGA listing is being prepared; trial results and listing are not yet established.

Publications

Research publications

2026Internet Interventions

Culturally adapted digital cognitive behavioral therapy for insomnia in South Korea – a double-blind randomized controlled trial

Evaluating culturally adapted digital CBT-I in South Korea.

Study details

SleepQ versus patient education

Double-blind · Randomized controlled trial

Assessment of sleep quality and sleep-related beliefs

A comparison of insomnia symptoms and sleep-related outcomes

Trial registration · NCT05822999
Read the paper
2025JMIR

Validating the Efficacy of a Mobile Digital Therapeutic for Insomnia (WELT-I): Randomized Controlled Decentralized Clinical Trial

Evaluating SleepQ through a randomized decentralized clinical trial.

Read the paper
2025Scientific Reports

Adjunctive smart ring monitoring during digital cognitive behavioral therapy for insomnia

An exploratory study using smart rings alongside sleep diaries.

Study details

Adjunctive smart ring monitoring

Single-arm · Pre-post study

Feasibility and adherence of sleep monitoring

28 completed the program · Exploratory study without a control group

Trial registration · NCT06339853
Read the paper
2025Yonsei Medical Journal

Impact of Adherence to Digital Cognitive Behavioral Therapy for Insomnia Effectiveness

Adherence and insomnia treatment outcomes

Study details

Adherence and treatment outcomes

Analysis of digital CBT-I data

Treatment outcomes by program adherence

A study of the relationship between adherence and outcomes

Read the paper
Regulatory milestones

Regulatory and prescribing milestones

2023

SleepQ® MFDS authorization; first integrated innovative-device review

2025

SleepQ® prescribing and evaluation fees; SerenQ® MFDS authorization; SleepQ® CE(MDR)

2026

Nationwide SleepQ® prescribing · SerenQ® NET certification

Quality & certification

Authorization and quality management

MFDS

Two authorized medical devices

CE (MDR)

European medical-device certification

ISO 13485

Medical-device quality management

ISO 27001

Information security management

KGMP

Manufacturing & quality management

NET

NET certification