Abstract

Objectives
This study evaluated the changes in hygiene management performance in long-term care institutions for older adults, following repeated hygiene and safety monitoring visits conducted by the Center for Social Welfare Foodservice Management.
Methods
This retrospective, longitudinal, observational study included 29 long-term care institutions for older adults registered with the Dobong-gu Center for Social Welfare Foodservice Management in Seoul, South Korea, that prepared meals on-site. Hygiene and safety monitoring visits were conducted up to six times from January to December 2025. Hygiene management was assessed using a 29-item checklist across six domains. Changes in the overall hygiene management scores and domain scores (%) by visit round were analyzed using linear mixed-effects models to account for repeated measurements within institutions and an unbalanced repeated-measures data structure.
Results
The mean hygiene management score increased from 85.76 at visit 1 to 90.91 at visit six. In the linear mixed-effects model, visit round was positively associated with hygiene management score, with an average increase of 0.89 points per additional visit (β = 0.89, P < 0.001). Institution type, institution size, foodservice operation type, and number of cooks were not significantly associated with hygiene management scores. When the visit round was treated as a categorical variable, the scores at the first and second visits were significantly lower than those at the sixth visit, whereas no significant differences were observed from the third visit onward. Significant increases in the mean domain scores were observed for personal hygiene, ingredient management, storage management, and other items. In the item-level analyses, implementation status was significantly associated with higher overall hygiene management scores for 11 of the 15 analyzable items, and all personal hygiene-related items showed significant associations.
Conclusion
Repeated hygiene and safety monitoring visits were associated with improved hygiene management performance in long-term care institutions for older adults, particularly during the early stages of repeated visits. Such field-based guidance and feedback may contribute to the strengthening of hygiene management practices in small-scale institutions.

• Keywords: long-term care institutions; Center for Social Welfare Foodservice Management; hygiene management; monitoring visits; linear mixed-effects model