Abstract
Objective: To develop a scale to quantify and discriminate orthostatic from non-orthostatic symptoms. In the current study, we present validation and reliability of orthostatic and non-orthostatic symptom scores taken from the orthostatic discriminate and severity scale (ODSS). Methods: Validity and reliability were assessed in participants with and without orthostatic intolerance. Convergent validity was assessed by correlating symptoms scores with previously validated tools [autonomic symptom profile (ASP) and the orthostatic hypotension questionnaire (OHQ)]. Clinical validity was assessed by correlating scores against standardized autonomic testing. Test–retest reliability was calculated using an intra-class correlation coefficient. Results: Convergent validity: orthostatic (OS) and non-orthostatic (NS) symptom scores from 77 controls and 67 patients with orthostatic intolerance were highly correlated with both the orthostatic intolerance index of the ASP (OS: r = 0.903; NS: r = 0.651; p < 0.001) and the composite score of the OHQ: (OS: r = 0.800; NS: r = 0.574; p < 0.001). Clinical validity: symptom scores were significantly correlated with the total composite autonomic severity score (OS: r = 0.458; NS: r = 0.315; p < 0.001), and the systolic blood pressure change during head-up tilt (OS: r = − 0.445; NS: r = − 0.354; p < 0.001). In addition, patients with orthostatic intolerance had significantly higher symptom scores compared to controls (OS: 66.5 ± 18.1 vs. 17.4 ± 12.9; NS: 19.9 ± 11.3 vs. 10.2 ± 6.8; p < 0.001, respectively). Test–retest reliability: Both orthostatic and non-orthostatic symptom scores were highly reliable (OS: r = 0.956 and NS: r = 0.574, respectively; p < 0.001) with an internal consistency of 0.978 and 0.729, respectively. Interpretation: Our initial results demonstrate that the ODSS is capable of producing valid and reliable orthostatic and non-orthostatic symptom scores. Further studies are ongoing to test sensitivity, specificity and symptom severity.
Original language | English (US) |
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Pages (from-to) | 105-112 |
Number of pages | 8 |
Journal | Clinical Autonomic Research |
Volume | 29 |
Issue number | 1 |
DOIs | |
State | Published - Feb 11 2019 |
Keywords
- Autonomic dysfunction
- Autonomic reflex screen
- Orthostatic intolerance
- Questionnaires
ASJC Scopus subject areas
- Endocrine and Autonomic Systems
- Clinical Neurology