Coronary artery bypass grafting (CABG) remains one of the most commonly performed cardiac surgeries worldwide. Despite surgical advancements, a significant proportion of patients experience psychological distress following surgery, with depression being particularly common. Current evidence regarding the effectiveness of preoperative psychological interventions in improving postoperative mental health outcomes remains inconclusive. There is a critical need for predictive models that can identify patients at risk of developing clinically significant depressive symptoms (CSDSs) and related psychological conditions after CABG. This multicentre observational study aims to develop and validate prognostic models for predicting CSDSs and other psychological outcomes, including anxiety, post-traumatic stress symptoms and quality of life, 6 weeks after elective CABG surgery.

The study will recruit 300 adult patients undergoing elective CABG (with or without valve intervention) across two Swiss hospitals. Data collected will include demographic, clinical, psychometric, inflammation-related and interoceptive variables. A training set (n=200) will be used to develop predictive models using machine learning, while a held-out test set (n=100) will be used for model validation. The primary outcome prediction will focus on CSDSs, assessed using the Patient Health Questionnaire-9 (PHQ-9), with analyses conducted both categorically (PHQ-9 total score ≥10) and continuously as complementary approaches. Secondary models will address anxiety, using the General Anxiety Disorder Scale-7, post-traumatic stress, using the post-traumatic stress disorder checklist for Diagnostic and Statistical Manual of Mental Disorders-5 and health-related quality of life, using the 12-item Short Form Survey. A simplified ‘light solution’ model with fewer predictors will also be developed for broader applicability. This study will address an important gap in perioperative mental healthcare by identifying key predictors of psychological morbidity following CABG, particularly CSDSs. The resulting models may inform future screening and preventive strategies and improve postsurgical outcomes through early identification and intervention in high-risk individuals.

The responsible ethics committee has reviewed and approved this project (Kantonale Ethikkommission Zürich, BASEC number: 2023-02040). The study minimises participant burden by integrating brief validated instruments and limiting psychiatric interviews to relevant outcomes, while ensuring ethical safeguards and respect for participant rights (including written consent). Results will be shared through peer-reviewed publications, conference presentations and stakeholder meetings involving clinicians and mental health professionals. Findings will also be communicated to participating centres and patient communities in accessible formats.

Perinatal complications involving conflicts between maternal and fetal health interests present a unique challenge to health economic evaluations. No comprehensive synthesis exists of how such studies account for dual-patient outcomes. We aim to develop a scoping review protocol to map and critically examine the methodologies in this understudied area.

The scoping review will be conducted under the Joanna Briggs Institute (JBI) framework. It will include health economic studies, such as cost-effectiveness, cost utility and decision analysis studies, focusing on clinical conditions during pregnancy where maternal and fetal interests conflict. Cost analysis without effectiveness assessment will be excluded. Using comprehensive search strategies in Medline (Ovid), EMBASE (Elsevier) and Cochrane Library (Wiley), two independent reviewers will screen and identify relevant studies via abstract and full-text review. We will perform data extraction following an adapted form from the Consolidated Health Economic Evaluation Reporting Standards checklist, which includes the content details, such as the type of study, population, intervention, comparator, probability, utility, duration, cost, model types and uncertainty measurements. As we try to explore the impact of the health economic studies in clinical practice, we will include citation metrics of each study and whether the study was cited by practice guidelines and clinical trials in the data extraction. We will also apply the JBI Checklist for Economic Evaluations to assess the reporting completeness in each article. Results will be tabulated by clinical theme and synthesised narratively to highlight patterns in valuation approaches, gaps in current methods and impact on clinical guidelines.

This study does not require ethical approval as it involves secondary analysis of published data. Findings will be disseminated through peer-reviewed publications, conference presentations and stakeholder engagement activities.

CRD42024557324