Exploring a set of Sniffin’ sticks suitable for olfactory screening in Chinese patients with Parkinson disease

ObjectiveTo develop a set of smell sticks suitable for olfactory detection in Chinese patients with Parkinson’s disease (PD).MethodsWe retrospectively conducted olfactory testing using 16 odor smell sticks administered to 133 PD patients and 103 healthy controls. Multiple combinations of odor sets—including SIT-16, SIT-12, and Ch-SIT-12 were evaluated. The correct identification rates for each odor were compared between the two groups. Receiver operating characteristic (ROC) curves were generated for different odor sets, and a random forest model algorithm was employed to establish an optimized set of smell sticks.ResultsThe PD group showed significantly lower correct identification rates for all odors except clove compared to the control group (PCI: 0.76-0.87), 0.80 (95%CI: 0.75-0.86), and 0.80 (95%CI: 0.74-0.85), respectively. Using the random forest model, a combination of 10 smell sticks (Ch-SIT-10) achieved an AUC of 0.81 (95%CI: 0.75-0.86). At a cutoff value of 7.5, this combination demonstrated a sensitivity of 76% and a specificity of 81%, that was similar to other SIT screening tests.ConclusionsThe enhanced Ch-SIT-10 test provides a faster and convenient method for screening olfactory dysfunction in Chinese PD patients.