Excerpts
Methodology
Patients were identified retrospectively from the Australian POTS Registry, which collects information on individuals 16 years and older with a physician-confirmed diagnosis of POTS. All registry participants who identified a viral, concussion or trauma trigger for the onset of POTS symptoms were included. POTS diagnosis for registry enrolment was determined using international criteria, namely unexplained orthostatic symptoms for a minimum of 3 months, in addition to a sustained heart rate increase of ≥ 30 beats per minute (≥ 40 bpm in adolescents) during a 10-min active stand test or head-up tilt table test, with an absence of orthostatic hypotension (defined as a drop of ≥ 20mmHg systolic or ≥ 10mmHg diastolic blood pressure within the first 3 min of standing) [
1,
11].
...
Primary outcomes were differences in HrQOL, as measured by the EuroQol 5-dimensional instrument (EQ-5D-5L), autonomic symptom burden as measured by the Composite Autonomic Symptom Score (COMPASS-31), gastrointestinal symptom burden as measured by the Gastroparesis Cardinal Symptom Index (GCSI), and fatigue as measured by the Fatigue Severity Scale-9 (FSS). Secondary outcomes were differences in demographics including education and employment status, socialisation, age of symptom onset, diagnostic delay, symptom duration, ED attendance prior to diagnosis and common comorbidities. Differences in self-reported historical hypermobility were examined using the Hakim five-point hypermobility questionnaire [
12].
...
The EQ-5D-5L tool evaluates health status across five dimensions (mobility, personal care, usual activities, pain/discomfort and anxiety/depression) and includes a visual analogue scale (EQ-VAS) which provides a global health assessment from 0 to 100, where 100 represents ‘full health’. Additionally, an EQ-utility score was generated from the UK Devlin set, between 0 and 1, with 1 representing ‘full health’ [
13]. The COMPASS-31 measures autonomic symptom burden across the domains of orthostatic intolerance, secretomotor, vasomotor, gastrointestinal, bladder and pupillomotor function [
14]. Although there is no validated cut-off score for discrimination of symptom severity in POTS specifically, a score of > 40 is considered suggestive of severe autonomic dysfunction. The GCSI uses a Likert-scale measure from 0 to 5, and consists of the subscales of post-prandial fullness/early satiety, nausea/vomiting and bloating. A total score of ≥ 2 indicates moderate to severe upper gastrointestinal tract symptoms [
15]. The FSS measures fatigue level, with a score of ≥ 36 out of 63 indicating severe fatigue [
16].
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