Table 3. Multivariate negative binomial regression on epilepsy incidence and prevalence^*.

Independent variable		Incidence		Prevalence
		IRR (95% CI)	p-value	OR (95% CI)	p-value
Age (vs. 65-74 y/o)	75-84 y/o	0.64 (0.50-0.82)	<0.001	0.61 (0.54-0.70)	<0.001
	85+ y/o	0.43 (0.31-0.60)		0.33 (0.27-0.40)
Male (vs. female)		1.05 (0.84-1.33)	0.652	1.13 (1.00-1.28)	0.045
Race (vs. non-Hispanic whites)	Hispanics	0.91 (0.70-1.18)	0.452	0.86 (0.74-0.99)	0.003
	Non-Hispanic blacks	1.28 (0.78-2.08)		1.33 (1.03-1.72)
	Non-Hispanic others	0.85 (0.62-1.17)		1.10 (0.94-1.29)
Location (vs. rural-rural counties)	Urban-rural counties	1.54 (1.01-2.37)	0.128	0.85 (0.65-1.11)	0.419
	Urban-urban counties	1.04 (0.82-1.32)		0.94 (0.83-1.07)
Married (vs. not)		0.88 (0.69-1.13)	0.332	0.85 (0.74-0.98)	0.021
Anoxic brain injury (vs. not)		7.37 (1.73-31.40)	0.007	1.69 (0.82-3.45)	0.153
Stroke (vs. not)		4.65 (3.54-6.11)	<0.001	3.81 (3.34-4.33)	<0.001
Atherosclerosis (vs. not)		1.00 (0.74-1.35)	0.998	1.18 (1.01-1.38)	0.032
Primary brain tumor (vs. not)		11.12 (2.18-56.59)	0.004	4.44 (2.14-9.20)	<0.001
Alzheimer's disease (vs. not)		2.25 (1.56-3.27)	<0.001	1.45 (1.20-1.76)	<0.001
Parkinson's disease (vs. not)		1.71 (0.99-2.97)	0.057	1.69 (1.30-2.20)	<0.001
Dementia (vs. not)		2.04 (1.44-2.88)	<0.001	2.26 (1.90-2.69)	<0.001
Hypertension (vs. not)		2.86 (2.22-3.69)	<0.001	1.81 (1.58-2.07)	<0.001
Sleep apnea (vs. not)		1.34 (0.91-1.97)	0.144	1.09 (0.88-1.35)	0.431

^*p-value of alpha (the overdispersion parameter) <0.001.

95% CI: 95 percent confidence interval, IRR: incidence rate ratio, OR: odds ratio, y/o: years old.