• Cancer
• Terminal care
• Hospice care

Terminally ill patients with cancer suffer from various troublesome symptoms, including oral problems, which have a significantly detrimental effect on their quality of life but are often not considered a priority.1 Some studies have demonstrated that simple oral care can improve oral problems,2 but this effect may be transient and deteriorate in the long run. Furthermore, oral problems can be an indirect cause of mortality in patients with advanced cancer, that is, oral colonisation can lead to systemic infection.3 Research has suggested that oral status is associated with poor survival in the palliative care setting4; however, to date, we are not aware of previous studies that have investigated the impact of oral care on survival.

We designed a nested case–control study in a palliative care unit of Korea University Guro Hospital, South Korea. All patients were terminally ill with cancer, likely to die within months and referred from home care or other facilities. The case group was from an intervention study conducted in August–December 2022, the aim of which was to examine the change of oral status by 1-week oral care. The controls were patients admitted during the same duration (5 months, March–July 2022). The eligibility criteria for both groups were the absence of head and neck cancer and admission to a palliative care …