The effect of the 2018 Japan Floods on cognitive decline among long-term care insurance users in Japan: a retrospective cohort study

Table 1 Demographic characteristics

		Disaster victims		Non-victims of the disaster		p value
		n = 2908		n = 261,671		p value
Age, no. (%)	Under 65	56	(1.93)	4466	(1.71)	0.019^a
	65–74	298	(10.25)	25,264	(9.65)
	75–84	979	(33.67)	82,661	(31.59)
	over 85	1575	(54.16)	149,280	(57.05)
	85–89	825	(28.37)	72,873	(27.85)	0.017^a
	90–94	529	(18.19)	53,322	(20.38)
	over 95	221	(7.60)	23,085	(8.82)
Gender, no. (%)	Male	874	(30.06)	75,345	(28.79)	0.135^a
Gender, no. (%)	Female	2034	(68.94)	186,326	(71.21)	0.135^a
Level of dementia symptomatology assessment before disaster, no. (%)	Independent	445	(15.30)	37,792	(14.44)	< 0.001^a
	I	574	(19.74)	47,321	(18.08)
	II a	381	(13.10)	33,152	(12.67)
	II b	575	(19.77)	50,756	(19.40)
	III a	467	(16.06)	47,708	(18.23)
	III b	203	(6.98)	18,638	(7.12)
	IV	263	(9.04)	26,304	(10.05)
Facility residents, no. (%)		655	(22.52)	78,826	(30.12)	< 0.001^a
Use of facilities that were shut down after the disaster		652	(22.42)	8995	(3.44)	< 0.001^a
Population density (per 1000/km²), median (IQR)^d		1.45	(0.57–1.86)	1.65	(0.70–1.89)	< 0.001^b
Care level re-certification, no. (%)		1,136	(39.1)	93,519	(8.92)	< 0.001^a
Cognitive decline, no. (%)		305	(10.5)	23,349	(24.5)	0.003^a
1 level down, no. (%)		145	(4.99)	11,626	(4.44)	0.27^a
2 level down, no. (%)		83	(2.85)	6562	(2.51)
3 or more level down, no. (%)		77	(2.65)	5161	(1.97)
Observation period, median (IQR)		6	(6–6)	6	(6–6)	0.27^c
Incident rate (95% confidential interval)		0.018	(0.016–0.020)	0.016	(0.016–0.016)

^aChi-squared test, ^bWilcoxon rank-sum test, ^cKruskal-Wallis test
^dThe data on population density in each municipality extracted from the Statistics Bureau, Ministry of Internal Affairs and Communications [24]

ISSN: 1347-4715