The Spider; A Multisystemic Symptom Impact Tool for People with Hypermobility-Related Disorders. Initial Validation...

The multisystemic comorbid symptoms/conditions of hypermobility spectrum disorders (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS) often significantly affect daily life. Many of these symptoms are under-recognized during diagnosis and treatment; therefore, a comprehensive questionnaire was developed to evaluate their presence and impact. The Spider's 8 domains assess neuromusculoskeletal, pain, fatigue, cardiac dysautonomia, urogenital, gastrointestinal, anxiety, and depression symptoms. This study aims to evaluate the construct validity of the Spider in adolescents.

This cross-sectional study recruited international participants through 3 patient charities and a hypermobility unit. Adolescents aged 13-18 years, with and without HSD/hEDS, were included. Validated and frequently used comparator questionnaires were used to establish convergent validity. Participants answered each Spider domain and the respective comparator via 4 online surveys. Convergent validity was assessed by comparing Spider domain and comparator scores through correlational analysis. Known-group validity was assessed by comparing Spider domain scores of hypermobile and control groups using Mann-Whitney U analysis.

In total, 1154 adolescents participated, 1036 with HSD/hEDS and 118 controls. Six domains (pain, fatigue, depression, cardiac dysautonomia, gastrointestinal, and neuromusculoskeletal) demonstrated strong correlations (r = -0.7 to 0.8) with the respective comparator. The urogenital and anxiety domains showed moderate correlations (r = 0.6). All correlations reached statistical significance (P < .001). Known-group validity was demonstrated in 7 domains (P < .001). The urogenital domain did not show a significant difference between the groups (P = .094).

The Spider domains demonstrate acceptable convergent validity. The Spider questionnaire can accurately, rapidly, and concisely measure the effect of common multisystemic comorbid symptoms/conditions associated with HSD/hEDS to help direct care in adolescents.