Effectiveness of a Waitlist App "Stappvoorstap" During Mental Healthcare Waiting Times

Bridging the Gap: A Multiple Baseline Design Study on the Effectiveness of a Mobile-based Stress Management Intervention in Adults on Waiting Lists for Mental Healthcare

This study evaluates the effectiveness of Stappvoorstap, a mobile self-management application designed for adults on mental health waiting lists in the Netherlands. The app helps users monitor daily stress levels, recognize personal stress patterns, and provides coping strategies, relaxation exercises, and supportive resources. Using a multiple baseline single-case experimental design, participants use the app for 4 weeks while completing weekly questionnaires measuring perceived stress, coping self-efficacy, and quality of life. The study aims to determine whether the app can reduce stress and improve wellbeing during the waiting period before mental healthcare treatment begins.

Prolonged waiting times for mental healthcare pose significant challenges, with nearly 100,000 people on waiting lists in the Netherlands as of December 2023. During this period, symptoms can worsen, daily functioning may decline, and quality of life decreases. Stappvoorstap was developed in co-creation with waitlist clients and experts-by-experience to address this gap. The app is based on stress-signaling plans used in Dutch mental healthcare and functions as an ecological momentary intervention. It measures perceived stress 2-4 times daily, creates visual overviews of stress patterns, and provides real-time coping suggestions, mindfulness exercises, informational articles, and personal stories from other clients. This study uses a nonconcurrent multiple baseline design with A-B-A design. Participants are randomly assigned to 3, 4, or 5-week baseline phases, followed by 4 weeks of app use, and 3 weeks of follow-up. Weekly assessments include the Perceived Stress Scale (PSS-10), Coping Self-Efficacy Scale (CSES-13), and WHOQOL-BREF. Both group-level and individual case analyses will be conducted using mixed-effects modeling and Tau-(BC) effect size measures.

Participants are recruited from mental health waiting lists across the Netherlands. As this is a mobile app-based intervention, participation is location-independent and takes place remotely.

Inclusion Criteria:

• Currently on a waiting list at a mental health organization in the Netherlands.
• Aged 18 years or older
• Owns a smartphone and has the ability to operate it
• Sufficient proficiency in Dutch or English language (at least B1 level)

Exclusion Criteria:

• Currently enrolled in another medical-scientific research study