Why Wait?:(Cost-)effectiveness and Process Evaluation Online, Transdiagnostic Positive Psychology Intervention for Patients Awaiting Psychological Treatment and their Loved Ones: Study Protocol for a Dutch RSCD and RCT

Background: Wait-lists for psychological treatment are growing<br/>due to imbalances between supply and demand in Dutch mental<br/>healthcare. Time spent on a wait-list is associated with symptomatic aggravation, suboptimal recovery and increased drop-out during<br/>treatment, causing societal expenses. An eHealth, transdiagnostic<br/>positive psychology intervention (eHealth PPI) may increase resilience among patients awaiting psychological treatment, potentially<br/>promoting recovery in a (cost-)effective manner. In contemporary<br/>healthcare research, the patient’s loved ones are often underrepresented. In light of caregiver burden, loved ones will be included in<br/>our intervention, potentially enhancing its clinical reach.<br/>Aims of the Study: The current paper proposes a study protocol<br/>aimed at examining the (cost-)effectiveness and process evaluation<br/>of an eHealth PPI for patients with various mental health complaints<br/>awaiting psychological treatment and their loved ones.<br/>Methods: Our study protocol represents a methodological framework for two studies (study 1 and study 2) aimed at examining the<br/>proposed eHealth PPI, using three analytical pillars: (1) clinical effectiveness, (2) economic evaluation and (3) process evaluation. In<br/>study 1, the working mechanisms and acceptability of the eHealth<br/>PPI will be examined, using a replicated single case design (RSCD)<br/>with 9 measurements in 9 weeks. In study 2, a randomized control trial (RCT) will examine the (cost-)effectiveness of the eHealth<br/>PPI, using measurements at baseline, post-intervention, after 3, 6, 9<br/>months and 1 year following PPI completion and 1 year following<br/>treatment completion. To assess the additional effects of including<br/>loved ones, the RCT will employ three arms: (1) eHealth PPI during<br/>waitlist + patient treatment, (2) eHealth PPI during waitlist for patients and loved ones + patient treatment, (3) wait-list before intake<br/>as usual + patient treatment.<br/>Results: Using validated questionnaires, primary outcomes will include positive mental health, mental complaints, quality of life, optimism and societal costs. Secondary outcomes include acceptability<br/>and adherence.<br/>Discussion and Limitations: To our knowledge, this is the first paper proposing a threefold evaluation of an eHealth PPI, using two<br/>studies. Suboptimal intervention adherence due to low literacy must<br/>be addressed. Likewise, patient dropout due to extensive measurements must be prevented.<br/>S51<br/>Implications for Health Care Provision and Use: Introducing the<br/>proposed eHealth PPI to various patients awaiting psychological<br/>treatment and their loved ones may help optimize clinical patient<br/>outcomes of subsequent mental health treatments, while also potentially reducing societal costs.<br/>Implications for Health Policies: Considering the broader trends<br/>in healthcare digitization, our expected results may inform policy<br/>decisions regarding financial resource allocation for implementing<br/>eHealth PPIs on a larger scale in mental healthcare.<br/>Implications for Further Research: Addressing the proposed<br/>research gaps may enhance our academic understanding of digital<br/>PPIs. Future studies may expand the body of evidence on (cost-)<br/>effective PPI applications for multiple patient populations.<br/>Source of Funding: A grant has been awarded to the current project<br/>by the Dutch Organization for Health Research and Development<br/>(ZonMw). The related grant number is: 06360312210054.