Table 4 Multivariate regression analysis for factors associated with prescription of PIM^a according to the 2012 Beers Criteria

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 NHI^b

0.88 (0.85–0.90)

0.83 (0.78–0.88)

No. of OPD^c visits within 1 year (≤1 vs. >1)

0.79 (0.78–0.80)

0.68 (0.65–0.71)

Severity of comorbidities^d

1.21 (1.19–1.22)

2.25 (2.20–2.31)

Polypharmacy^e

3.51 (3.46–3.56)

7.81 (7.56–8.06)