Page 159 - Demo

Development and validation of the TSC-PROM1576The most important part of the development of the TSC-PROM is content validity65 which was ensured and verified by all major stakeholders, including individuals with TSC and a broad multidisciplinary team of TSC experts. Some adjustments were made based on the feedback received during the cognitive interview study in the participating countries, and feasibility, comprehensibility, relevance, and comprehensiveness were demonstrated. However, cross-cultural validity has not yet been examined, and cultural adaptations may be necessary when using the TSC-PROM in other countries and languages. Satisfactory results were demonstrated on internal consistency and structural validity. Unidimensionality was satisfied, but there was some overlap between items indicated by local dependencies. This may be explained by the fact that items were divided into clusters with overlap in content of symptoms which often co-exist. Satisfactory results were also demonstrated on construct validity, although not all hypotheses with regard to discriminative validity were met, in particular for the proxy version. These results may reflect the heterogeneity of the TSC population and indicate that function for individuals with TSC is difficult to determine by proxy-reports.42 Furthermore, higher scores of the TSC-PROM indicating better functioning were observed for self-ratings compared to proxy-ratings (p<0.001, r=-0.50), perhaps because the proxy-ratings concern individuals who are more affected by the neurological manifestations of TSC, or due to bias of the rating as in other studies proxy-raters often seem to assess functioning as worse.66–68Recommendations for use in the care setting The TSC-PROM can provide quantitative evaluation of the severity and impact of TSC on various health domains and daily functioning from the patient’s perspective. As such, it might be used for monitoring and informing care. The instrument might also serve as a tool to facilitate detection of healthcare needs before or during a clinical visit. Although it is an elaborate questionnaire and it might take some time to complete, it consists of all relevant items. However, not all items or domains are always applicable to individuals with TSC due to the heterogeneity and treatment goals. Therefore, a subdomain could be used as well rather than the whole instrument, although it might still be valuable to use all domains in order to not forget about possible manifestations. It ensures an effective follow-up Annelieke Muller sHL.indd 157 14-11-2023 09:07