Table 3. Factors associated with polypharmacy among patients with dementia (n = 57,346).

Variable		Polypharmacy (5+)			Excessive polypharmacy (10+)
		OR	95% CI	P-value	OR	95% CI	P-value
Sex	Male (ref.)
	Female	1.052	1.010–1.095	0.0143	0.937	0.897–0.979	0.0034
Age	60–64 (ref.)
	65–69	1.189	1.061–1.332	0.0030	1.180	1.026–1.358	0.0208
	70–74	1.458	1.312–1.619	<0.0001	1.519	1.337–1.726	<0.0001
	75–79	1.690	1.530–1.866	<0.0001	1.661	1.470–1.875	<0.0001
	80–84	1.543	1.399–1.703	<0.0001	1.483	1.313–1.674	<0.0001
	85–89	1.216	1.099–1.345	0.0001	1.152	1.016–1.306	0.0269
	90–91	1.002	0.887–1.132	0.9724	0.920	0.789–1.072	0.2851
Disability	Severe	0.858	0.803–0.916	<0.0001	0.959	0.893–1.030	0.2479
	Mild	1.245	1.184–1.309	<0.0001	1.316	1.252–1.383	<0.0001
	None (ref)
Region	Seoul-Metro (ref)
	Chungcheong	0.909	0.856–0.964	0.0016	0.966	0.905–1.032	0.3045
	Honam	0.884	0.837–0.933	<0.0001	1.145	1.081–1.213	<0.0001
	Gyeongsang	0.937	0.895–0.982	0.0060	1.038	0.987–1.092	0.1512
	Gangwon-Jeju	0.911	0.835–0.993	0.0332	0.928	0.844–1.022	0.1285
Income level	Medical Aid	1.206	1.135–1.281	<0.0001	1.688	1.590–1.792	<0.0001
	NHI 1st	0.934	0.882–0.988	0.0172	1.079	1.012–1.149	0.0191
	NHI 2nd	0.901	0.838–0.968	0.0044	1.015	0.935–1.103	0.7163
	NHI 3rd	0.953	0.896–1.014	0.1292	1.018	0.949–1.091	0.6229
	NHI 4th	0.998	0.944–1.055	0.9471	1.033	0.972–1.099	0.2972
	NHI 5th (richest, ref.)
Type of long-term care benefits	Institutional care	1.366	1.287–1.451	<0.0001	0.986	0.924–1.051	0.6588
	Home care	1.266	1.212–1.323	<0.0001	1.193	1.139–1.250	<0.0001
	None (ref.)
Duration of dementia (years)	<1 (ref.)
	1–3	1.187	1.128–1.249	<0.0001	1.194	1.130–1.262	<0.0001
	3–10	1.216	1.163–1.272	<0.0001	1.208	1.151–1.268	<0.0001
	≥10	1.263	1.156–1.380	<0.0001	1.270	1.157–1.393	<0.0001
CCI	≤2 (ref.)
	3–4	1.960	1.878–2.046	<0.0001	2.477	2.341–2.620	<0.0001
	≥5	2.910	2.775–3.052	<0.0001	4.524	4.280–4.782	<0.0001

Ref.: reference

NHI: National Health Insurance, CCI: Charlson comorbidity index