Multimorbidity, functional impairment and health-related quality of life in postural orthostatic tachycardia syndrome: findings from an Australian observational cohort study

To characterise the symptom, comorbidity and diagnostic journey of adult and older adolescent patients with postural orthostatic tachycardia syndrome (POTS). Cross-sectional observational cohort study. Participants ≥16 years old with physician-confirmed POTS who enrolled in the Australian POTS registry between 1 May 2021 and 30 April 2024 were included. 500 participants enrolled in the Australian POTS registry. Health-related quality of life and symptom severity were assessed using validated patient-reported outcome measures, including the Composite Autonomic Symptom Score, EuroQol 5-Dimension-5 Level (EQ-5D), Gastroparesis Cardinal Symptom Index (GCSI), Fatigue Severity Scale (FSS) and the 5-point hypermobility index scores. Sociodemographics, diagnostic journey details and comorbidities were obtained via self-reported questionnaires and reconciled with medical records by the clinical team. Among 500 participants (86.8% females, 92.7% White; mean age 31.3±11.7 years), the median diagnostic delay was 3.0 years (IQR 9.0; mean 6.7 years), with 25.5% experiencing a delay of ≥10 years. Despite being young and highly educated, 22.0% were unemployed or unable to attend education. Infection was the most frequently identified proximal trigger and accounted for 39.4% of cases. Higher autonomic symptom burden, as reported on the Composite Autonomic Symptoms Score (COMPASS-31) questionnaire, was associated with greater fatigue (FSS: 56.0±8.8 vs 48.0±14.5; p<0.001), gastrointestinal symptoms (GCSI: 1.60±0.77 vs 0.89±0.63; p<0.001), increased healthcare utilisation and worse quality of life (EQ-5D utility: 0.547±0.237 vs 0.717±0.200; p<0.001), assessed using Mann-Whitney U and χ tests as appropriate. POTS is associated with significant diagnostic delays, high healthcare utilisation, substantial symptom burden, educational, social and occupational impacts. Patient-reported outcome measures such as the COMPASS-31 questionnaire can assist in identifying high-risk individuals. Systemic healthcare reform is urgently needed to improve access to timely diagnosis and effective treatment for individuals living with POTS. ACTRN12621001034820.