Table 4.

Multivariate regression analysis for factors associated with prescription of PIM^a according to the 2012 Beers Criteria

	Subjects with 1–4 PIM claims	Subjects with ≥5 PIM claims
Characteristics	OR (95% CI)	OR (95% CI)
Age, 65–69 years
70–74	0.98 (0.89–1.09)	1.16 (1.10–1.22)
75–79	1.16 (1.05–1.29)	1.33 (1.26–1.41)
80–84	1.50 (1.34–1.69)	1.61 (1.51–1.72)
≥85	1.89 (1.64–2.18)	1.93 (1.78–2.09)
Female gender	1.19 (1.17–1.21)	1.53 (1.48–1.59)
Specialty other than physician	1.23 (1.22–1.24)	1.46 (1.43–1.50)
Other than primary care facilities	0.84 (0.83–0.85)	0.72 (0.71–0.73)
Rural area	1.02 (1.00–1.04)	0.85 (0.82–0.88)
Insured by NHIb	0.88 (0.85–0.90)	0.83 (0.78–0.88)
No. of OPDc visits within 1 year (≤1 vs. >1)	0.79 (0.78–0.80)	0.68 (0.65–0.71)
Severity of comorbiditiesd	1.21 (1.19–1.22)	2.25 (2.20–2.31)
Polypharmacye	3.51 (3.46–3.56)	7.81 (7.56–8.06)

^aPIM, potentially inappropriate medication; ^bNHI, national health insurance; ^cOPD, outpatient department; ^dBased on Charlson Comorbidity Index¹³; ^ePolypharmacy defined as ≥6 medications prescribed in one claim²⁴