The included participants were adults older than 18 years and had a diagnosis of primary nOH. nOH is widely categorized into primary and secondary types.15 (link) Primary nOH is associated with underlying neurological disorders involving the autonomic nervous system, including PD, MSA, DLB, and PAF.15 (link) Secondary nOH is associated with spinal cord disorders and peripheral neuropathies such as amyloidosis and diabetes mellitus.15 (link) To exclude patients with secondary nOH, we obtained individual line-level data from the authors of the relevant studies, including all causes of nOH, and excluded any data related to secondary nOH. Bedridden patients and those with contraindications to atomoxetine (e.g., coronary artery disease, abnormal liver function, and narrow-angle glaucoma) were also excluded.