Development and Validation of a Measurement Tool for Recording Health-Related Quality of Life in Long COVID-19 (QoLCOVI)

COVID-19 (Coronavirus Disease - 19) is increasingly associated with long-term symptoms that last more than 12 weeks after infection. With these long-term symptoms, which can be described as long COVID, even a mild course of COVID-19 can lead to serious long-lasting impairments, such as shortness of breath when simply climbing stairs or loss of smell and taste. There is a particular risk for patients who have had to be treated in intensive care due to a severe course. The long-term symptoms of COVID-19 obviously affect the physical, emotional, cognitive and psychosocial components of health-related quality of life (QoL). An instrument that systematically records these effects, however, has not yet been developed or validated. The main goal of this study is therefore to develop and validate a Long COVID-19 specific measurement tool that maps the QoL of Long COVID patients. The specific objectives of the study are 1) to identify limitations in QoL from the point of view of patients with Long COVID-19 symptoms, which should form the basis for the development of a conceptual model of QoL in Long COVID-19, 2) the generation of an item set, 3) assessing the content validity of these items, 4) systematically reducing the items and improving the instrument, 5) assessing the content validity, and 6) validating the final instrument including an interpretability and feasibility analysis. The Wilson and Cleary model of health-related QoL will be used as the basis for the development of the new instrument. Based on a systematic review of the literature and using qualitative research (patient and expert interviews, focus groups), a conceptual model (task 1) and a pool of items (task 2) will be developed first. After the content validation of this item set (task 3) a prototype instrument will be available. This prototype will be used in a quantitative study to subsequently reduce the number of items, identify the underlying factor structure and eliminate inappropriate items. In addition, the appropriateness of the response categories will be examined (task 4). The content validity of the final instrument will be examined again with the help of patient interviews and, in the best case, will be confirmed (task 5). The final instrument will finally be validated in a psychometric study (task 6). This project will result in a high-quality, content-valid, psychometrically-validated, and user-friendly tool tailored to the Long COVID-19-specific aspects of QoL that can be used in epidemiological research, clinical studies, and clinical practice in the future.