Development of an ICF-based scale for assessing quality of life in adults with congenital heart disease

Background Congenital heart disease (CHD), affecting approximately 0.9% of live births, now presents with markedly reduced mortality due to advances in diagnosis and treatment. Consequently, adults living with CHD now outnumber children, creating a demographic shift that reshapes disease management and underscores the need for population-specific assessment approaches. Purpose This study aimed to develop the first disease-specific, ICF-based quality-of-life scale designed specifically for adults with congenital heart disease. Methods A systematic review conducted by two experts identified ICF codes relevant to adults with CHD by examining body structures, body functions, activity, participation, and environmental and personal factors, as well as cardiac core sets. An initial pool of 39 codes was refined to 31 through evaluation by 16 experts, applying an acceptance threshold of at least 80%. Conceptually similar codes were merged to create a clinically applicable 21-item preliminary scale in line with ICF principles. Content validity was assessed by nine experts using the Lawshe method; three items with inadequate validity were removed, and the remaining 18 were revised and re-evaluated, achieving sufficient validity. The final scale utilised a 5-point Likert response format. A pilot study including 25 adults with CHD assessed feasibility, comprehensibility, and applicability. All items were considered clear and feasible by participants, with no major implementation issues reported. Results Expert assessments confirmed agreement for 31 ICF codes, which were subsequently refined by merging overlapping or complementary concepts. Three items with Content Validity Ratio values below 0.75 were removed, yielding a scale-level Content Validity Index of 0.96. The final scale comprises 18 items: 6 addressing Body Functions, 7 addressing Activity and Participation, and 5 addressing Environmental Factors. The pilot participants (14 women, 11 men) had a mean age of 25.1 ± 8.64 years. Conclusion This study outlines the development of an ICF-based quality-of-life scale for adults with CHD, encompassing body functions, activity–participation, and environmental domains. The resulting instrument provides a disease-specific, standardised, and patient-centred framework for evaluating key aspects of quality of life, with potential application in both clinical practice and research settings. Although promising, further research is required to establish the scale’s psychometric properties, including broader validity and reliability.