The study validates a rapid, semi-automated Next‑gen Olfactometry System (NOS) that shows moderate agreement with the standard OSIT‑J test, discriminates PD from high- and low-risk groups, and in exploratory analysis correlates with DAT SPECT in high‑risk individuals.

NOS offers a practical, scalable olfactory screening method to identify prodromal PD and enrich cohorts for early‑intervention trials and biomarker studies, aiding translational research and trial recruitment even though it does not report new mechanistic or therapeutic interventions.

BACKGROUND: Olfactory impairment is a key prodromal symptom of Parkinson's disease (PD), yet conventional Japanese olfactory tests require controlled rooms and time-consuming manual procedures, restricting large-scale use. The Next-gen Olfactometry System (NOS) provides rapid, semi-automated assessment. OBJECTIVES: We evaluate the clinical utility of the NOS as an efficient screening tool for PD-related olfactory dysfunction. METHODS: Twenty-three patients with PD, 21 high-risk individuals (≥2 prodromal symptoms), and 20 low-risk controls underwent NOS testing (recognition and detection thresholds and a composite score). Results were compared with the Odor Stick Identification Test for Japanese (OSIT-J) to evaluate correlation and discriminative ability. RESULTS: NOS recognition and detection thresholds correlated moderately with OSIT-J (r = -0.676 and r = -0.516, both P < 0.001). NOS recognition thresholds were significantly worse in PD than in either risk group, but did not differ between risk groups. NOS detection thresholds and OSIT-J scores showed a graded decline-worst in PD, intermediate in high-risk, and best in low-risk-with every pairwise contrast significant. The NOS indices may discriminate between the PD and high-risk groups, as well as between the PD and low-risk groups. In the exploratory analysis, NOS recognition thresholds correlated moderately with the dopamine transporter single-photon-emission computed tomography specific binding ratio in the high-risk group. CONCLUSIONS: NOS indices showed moderate agreement with OSIT-J. Although NOS did not surpass OSIT-J in discrimination between high- and low-risk individuals, its rapid, semi-automated workflow makes it a practical option for large-scale olfactory screening in prodromal PD.