Table 3.

Multivariate analysis of factors associated with the prevalence of insomnia.

			Odds ratio	P	95% CI
Predictor for sleeplessness a
	Post-earthquake vs pre-earthquake		1.842	<.001	1.514–2.242
	Age ≥20 years vs age <20 years		2.246	.027	1.095–4.605
	Female vs male		1.510	.109	0.912–2.501
	Presence vs absence of pollinosis		2.334	.001	1.437–3.791
	Tokyo vs. Osaka		1.404	.187	0.848–2.323
	No reminder email vs reminder email		1.303	.016	1.050–1.617
Predictor of sleeplessness
	Tokyo
		Post-earthquake vs pre-earthquake	1.998	<.001	1.571–2.542
		Age ≥20 years vs age <20 years	1.378	.421	0.631–3.010
		Female vs male	1.670	.903	0.90–3.087
		Presence vs absence of pollinosis	2.437	.005	1.317–4.509
		No reminder email vs reminder email	1.435	.004	1.121–1.838
	Osaka
		Post-earthquake vs pre-earthquake	1.558	.011	1.106–2.196
		Age ≥20 years vs age <20 years	13.987	<.001	6.408–30.530
		Female vs male	1.285	.554	0.554–2.983
		Presence vs absence of pollinosis	2.193	.047	1.012–4.751
		No reminder email vs reminder email	1.005	.983	0.658–1.535

^a values are total counts from Tokyo and Osaka