BACKGROUNDThe increased survival rate among individuals with congenital heart disease (CHD) has sparked interest in their transition to adult healthcare. Although there is a general agreement on the importance of transition interventions, the empirical evidence supporting them is insufficient. Therefore, this study aimed to conduct a systematic review and meta-analysis of transition interventions for adult healthcare in adolescents and young adults.METHODS AND RESULTSA literature search was conducted for studies comparing the quantitative effects of transition interventions with control groups, published up to March 15, 2023, in major databases (CENTRAL, Embase, PubMed, Web of Science, CINAHL, KISS, and KMbase), major clinical trial registers, academic journal sites related to the topic, and grey literature databases. Ten studies involving a total of 1,297 participants were identified. Transition interventions proved effective in enhancing disease-related knowledge (Hedge’s g=0.89, 95% CI=0.29-1.48) and self-management (Hedge’s g=0.67, 95% CI=0.38-0.95), as well as reducing loss to follow-up (OR=0.41, 95% CI=0.22-0.77). The certainty of evidence for the estimated values of each major outcome was low or very low.CONCLUSIONSThis study supports the implementation of transition interventions by demonstrating that they can improve patients’ disease knowledge and self-management, while also promoting treatment continuity. However, since the available data on transition interventions for adolescents and young adults with CHD remain limited, the widespread adoption of structured transition interventions in the future may alter the conclusions of this study.REGISTRATIONURL:https://www.crd.york.ac.uk/PROSPERO. Unique identifier: CRD42023399026.CLINICAL PERSPECTIVEWhat Is New?This systematic review of transition programs for individuals of transitional age with congenital heart disease identified 10 relevant studies.Transition programs for adolescents and young adults with congenital heart disease were primarily designed to provide individual education, supplement roles related to anatomical and hemodynamic considerations, manage medications and medical appointments and facilitate communication with healthcare providers.The transition programs demonstrated efficacy in enhancing disease-related knowledge and self-management, as well as in reducing instances of loss to follow-up. However, they did not significantly improve disease-related quality of life.What Are the Clinical Implications?Given the ethical and practical considerations that arise from country-specific conditions and environments, research on congenital heart disease transition programs should utilize a feasible study design that incorporates a control group.Transition programs should address lifestyle factors that can enhance heart function and alleviate clinical symptoms. After promoting long-term commitment to these programs, it is necessary to assess the effects on disease-related quality of life.An execution of a transition program that takes into account the developmental characteristics of the target age group, as well as a transition program involving parents, is necessary. Subsequently, an analysis of the effects of these programs is also required.As a result of the transition program, it is necessary to measure and analyze not only process indicators but also outcome indicators that directly reflect an individual’s health (e.g. emergency room visits, hospital admissions, and the status of disease or complications).