Table 3.

Factors influencing rate of polypharmacy in older patients with multilevel adjusted final models

Variables	Overall, OR (95% CI)	Public sector, OR (95% CI)	Private sector, OR (95% CI)
Patient level
Age, median (IQR)	0.99 (0.96–1.02)	1.00 (0.96–1.04)	0.99 (0.94–1.04)
Gender	Reference: Male
Female	1.49 (1.11–1.99)*	1.76 (1.17–2.65)*	1.08 (0.53–2.19)
Ethnicity	Reference: Malay
Chinese	0.94 (0.58–1.53)	0.93 (0.50–1.74)	1.65 (0.23–1.63)
Indian	1.11 (0.56–2.18)	1.21 (0.53–2.77)	0.45 (0.06–3.29)
Other	2.16 (0.49–9.52)	1.02 (0.35–3.02)	4.20 (0.62–28.24)
Education level	Reference: No formal education
Primary	1.61 (1.12–2.32)*	1.68 (1.00–2.83)	1.69 (0.61–4.67)
Secondary	1.44 (0.93–2.23)	1.85 (0.99–3.46)	1.73 (0.59–5.05)
Tertiary	1.08 (0.47–2.5)	1.62 (0.51–5.17)	0.60 (0.07–5.34)
Multimorbidity	Reference: No
Yes	14.21 (8.46–23.88)*	36.37 (17.39–76.09)*	5.54 (2.03–15.13)*
Prescriber level
Experience	1.01 (0.97–1.05)	1.02 (0.96–1.09)	1.00 (0.96–1.06)
Working hours	1.00 (0.97–1.03)	0.97 (0.92–1.02)	1.01 (0.97–1.04)
Gender	Reference: Male
Female	1.14 (0.63–2.04)	0.64 (0.32–1.29)	0.83 (0.27–2.55)
FMS	Reference: No
Yes	2.81 (0.79–9.91)	4.66 (1.11–19.5)*	–
Place of graduation	Reference: Foreign
Local	1.16 (0.76–1.78)	0.96 (0.52–1.80)	0.78 (0.31–1.97)
Practice level
Workload	0.99 (0.97–1.00)	0.98 (0.97–1.00)	0.98 (0.96–1.01)
Sector	Reference: Private
Public	6.37 (1.17–34.71)*	–	–
Operation day per week	Reference: Five
Six	1.35 (0.50–3.62)	1.31 (0.76–2.24)	2.22 (0.17–29.28)
Seven	2.73 (0.88–8.45)	1.80 (0.20–16.27)	4.44 (0.29–67.57)
Practice with FMS	Reference: No
Yes	1.56 (0.63–3.84)	0.93 (0.41–2.09)	7.68 (0.72–82.32)
Practice type	Reference: Group
Solo	3.09 (0.94–10.11)	2.91 (0.16–53.1)	4.36 (0.98–19.31)
Urban location	Reference: No
Yes	0.74 (0.33–1.64)	0.78 (0.44–1.41)	0.82 (0.19–3.50)

OR, odds ratio; CI, confidence interval; IQR, interquartile range; FMS, family medicine specialist; Multimorbidity refers to having 2 or more chronic conditions; * p-value < .05