Validating the ADFSCI hypotension symptom domain as a scalable patient reported outcome measure in spinal cord injury

Hypotension is an under-recognized consequence of spinal cord injury (SCI). Clinical assessments, such as head-up tilt testing, are resource-intensive and carry safety risks. In this study, we evaluated the validity of the hypotension symptom domain of the Autonomic Dysfunction Following Spinal Cord Injury (ADFSCI) questionnaire as a patient-reported outcome measure for hypotension-related symptoms in individuals with SCI. Known-groups validity and convergent validity were supported by higher hypotension symptom scores in participants with physiologically defined orthostatic hypotension (OH). Discriminative performance for OH classification was acceptable, and symptom frequency, severity, and contextual triggers were each associated with greater physiological BP instability. Symptom-level analyses identified blurred vision, light-headedness, fatigue, weakness, and dizziness correlated with blood pressure declines. To assess real-world applicability, we also analyzed a global dataset of patient-reported ADFSCI responses from individuals with SCI, enabling population-scale characterization of hypotensive symptom burden. In this dataset, higher symptom scores were associated with female sex and higher neurological injury level. Together, these findings provide converging evidence of supporting the validity of the hypotension symptom domain as a scalable measure of hypotension symptom burden in SCI for use in remote assessment and screening.