Mochi-related vs other food-related foreign body airway obstruction: outcomes from the MOCHI registry

Background: Mochi (Japanese rice cake) is frequently implicated in severe foreign body airway obstruction (FBAO) due to its distinctive viscoelasticity and adhesive properties. However, it remains unclear whether mochi-related FBAO is associated with worse outcomes. Methods: In this nationwide prospective multicenter observational study (MOCHI registry), we analyzed patients with food-related FBAO transported to hospitals. The exposure was mochi-related FBAO and the comparator was other food-related FBAO. The primary outcome was 30-day survival; secondary outcome included favorable neurological outcome (Cerebral Performance Category [CPC] 1-2). We employed inverse probability of treatment weighting (IPTW) based on a propensity score model including age, sex, baseline functional status, comorbidities, event setting, witness status, and the New Year period. Results: Of 409 patients assessed for eligibility in the MOCHI registry, 399 were included in the final analysis; 63 (15.8%) presented with mochi-related FBAO. Mochi cases were more often ADL-independent (44/61 [72.1%] vs 128/329 [38.9%]) and had fewer comorbidities (e.g., dementia: 10/63 [15.9%] vs 116/336 [34.5%]; prior stroke: 5/63 [7.9%] vs 74/336 [22.0%]) and clustered at home during the New Year period. In the IPTW analysis, mochi was not significantly associated with 30-day survival (IPTW-weighted OR, 0.93; 95% CI, 0.41-2.11) or favorable neurological outcomes (IPTW-weighted OR, 0.87; 95% CI, 0.30-2.49). Conclusions: Mochi was not statistically significantly associated with 30-day outcomes after adjustment, but estimates were imprecise. Mochi-related events occurred disproportionately among relatively healthier, functionally independent individuals and occurred predominantly at home during seasonal consumption, supporting targeted seasonal prevention and public education in home settings.