To assess the validity and reliability of a novel Ehlers-Danlos Syndromes (EDS) disability index that longitudinally tracks EDS patient-reported outcomes.

EDS are a rare group of inherited connective tissue disorders characterized by defective collagen synthesis and processing. The clinical presentation of EDS is complex, often including but not limited to hypermobility, musculoskeletal disorders, and chronic pain that severely limit activities of daily living. In the absence of a curative treatment, a disease specific disability index utilizing patient-reported outcomes can advance treatment options and enhance EDS patients’ quality of life.  

An EDS-specific disability index was created with survey data and clinician feedback. 222 EDS patients in a multidisciplinary clinical program completed the index at initial and follow-up visits over one year. Initial visit data was subjected to exploratory and confirmatory factor analyses, as well as goodness of fit analysis. To refine the initial index, items were removed based on factor loading values. Paired t-tests were conducted for individual outcomes and factor subscales to evaluate the reliability of the index over time.

The exploratory factor analysis indicated a two-factor solution, accounting for 42.40% of data variance after rotation. Adequate model fit was observed through goodness of fit indices: Tucker and Lewis’s index (0.85) and root mean square error of approximation (0.1). The paired t-test analysis revealed significant improvement across three symptom related outcomes, one function related outcome, and the mean total score.  

Our preliminary findings further the development of a patient-reported disability index for EDS patients that comprehensively encompasses the various dimensions of disability they encounter.