Incidence and risk factors for norovirus-related diarrhea in Japanese geriatric intermediate care facilities: A prospective cohort study

Aim

The risk of developing infectious diarrhea among elderly residents at Japanese geriatric intermediate care facilities is unclear. We investigated the incidence rate and risk factors of norovirus-related diarrhea at such facilities.

Methods

This prospective cohort study followed 1727 residents from November 2018 to April 2020 at 10 geriatric intermediate care facilities in Osaka, Japan regarding the occurrence of diarrhea. Resident data were collected from their medical records using structured forms at two to three of the following three time points: at recruitment, if they developed diarrhea, and when they left the facility. Residents who developed diarrhea were tested using rapid diagnostic tests for norovirus. Cox proportional hazard model was employed to hazard ratios (HRs) with 95% confidence intervals (CIs) to estimate the risk factors for norovirus-related diarrhea.

Results

During the study period, 74 residents developed diarrhea, 13 of whom were norovirus positive. The incidence rate of norovirus-related diarrhea was 10.11 per 1000 person-years (95% CI: 4.61–15.61). In terms of risk factors, people with care-needs level 3 were at a higher risk for developing norovirus-related diarrhea (adjusted HR [aHR] = 7.35, 95% CI: 1.45–37.30). Residents with hypertension (aHR = 3.41, 95% CI: 1.05–11.04) or stroke (aHR = 8.84, 95% CI: 2.46–31.83), and those who walked with canes (aHR = 16.68, 95% CI: 1.35–206.52) also had a significantly higher risk for norovirus-related diarrhea.

Conclusions

Throughout the study period, the incidence of development of diarrhea was low. Care-needs level 3, stroke, hypertension and use of a cane were identified as risk factors for norovirus-related diarrhea in Japanese geriatric intermediate care facilities. Geriatr Gerontol Int 2023; 23: 179–187 .     

Functional outcomes and associated factors of cerebral infarction and intracerebral hemorrhage in an area with aging populations in change over time: Evidence from the Akita Stroke Registry

Aim

To examine secular change in functional outcomes and associated factors of stroke in a rapidly aging region.

Methods

We retrospectively analyzed cerebral infarction and intracerebral hemorrhage incidence registered cases in the Akita Stroke Registry from 1985 to 2014, divided into three of 10 years each. Functional outcome was defined as good with a modified Rankin scale score of 0–1 and poor with a score of 3–6 at discharge. Mixed effects logistic regression analysis with the location of medical facility as a random effects variable by disease type was used to examine the results.

Results

There were 81 254 eligible patients (cerebral infarction: 58 217, intracerebral hemorrhage: 23 037). Age at onset increased over time in both diseases (cerebral infarction: median [interquartile range] age, 70 [63–77] years in 1985–1994 to 77 [69–83] years in 2005–2014; intracerebral hemorrhage: 64 [56–72] years in 1985–1994 to 72 [61–80] years in 2005–2014). Multivariate analysis showed that the odds ratio associated with good outcomes increased over time for cerebral infarction, and cerebral hemorrhage increased in periods 2 and 3 compared with period 1, but decreased from period 2 to period 3. For cerebral infarction, the odds ratios of prior diabetes associated with poor outcomes decreased over time.

Conclusion

The age at onset increased over time. In cerebral infarction, functional outcomes improved over time, and the association between diabetes and poor outcome declined over time. It was speculated that these results were related to advances in the healthcare system and improved management of vascular risk factors during the study period. Intracerebral hemorrhage improved during the first 20 years, with no apparent improvement thereafter. Geriatr Gerontol Int 2023; 23: 486–492 .