Table 1 Baseline characteristics of the study population (N = 461,034)

Age, mean [SD]

76.1

[7.1]

76.2

[7.1]

76.1

[7.1]

0.8844

 65–74

204,246

(44.3)

9726

(44.3)

194,520

(44.3)

0.9743

 75–84

194,220

(42.1)

9238

(42.1)

184,982

(42.1)

0.9743

  ≥ 85

62,568

(13.6)

2990

(13.6)

59,578

(13.6)

0.9743

Gender, male

180,351

(39.1)

8627

(39.3)

171,724

(39.1)

0.5819

CCI score, mean [SD]

2.11

[1.93]

2.25

[2.16]

2.10

[1.92]

<.0001

 0

97,658

(21.2)

4658

(21.2)

93,000

(21.2)

0.9917

 1–2

198,912

(43.1)

9468

(43.1)

189,444

(43.2)

0.9917

  ≥ 3

164,464

(35.7)

7828

(35.7)

156,636

(35.7)

0.9917

 Health insurance

403,869

(87.6)

19,228

(87.6)

384,641

(87.6)

0.9355

 Medical aid

57,165

(12.4)

2726

(12.4)

54,439

(12.4)

0.9355

 Diabetes Mellitus

136,783

(29.7)

6702

(30.5)

130,081

(29.6)

0.0043

 COPD

73,613

(16.0)

4126

(18.8)

69,487

(15.8)

<.0001

 Cerebrovascular disease

64,855

(14.1)

3732

(17.0)

61,123

(13.9)

<.0001

 Coronary artery disease

59,108

(12.8)

3319

(15.1)

55,789

(12.7)

<.0001

 Liver failure

37,934

(8.2)

2215

(10.1)

35,719

(8.1)

<.0001

 Congestive heart failure

30,984

(6.7)

1813

(8.3)

29,171

(6.6)

<.0001

 Cancer

28,152

(6.1)

1640

(7.5)

26,512

(6.0)

<.0001

 Renal failure

10,927

(2.4)

778

(3.5)

10,149

(2.3)

<.0001

 Parkinson's disease

10,347

(2.2)

749

(3.4)

9598

(2.2)

<.0001

No. of concomitant drugs, mean [SD]

4.4

[3.9]

5.2

[4.4]

4.4

[3.9]

<.0001

  < 5

258,095

(56.0)

10,829

(49.3)

247,266

(56.3)

<.0001

 Polypharmacy (5–9)

153,316

(33.3)

7580

(34.5)

145,736

(33.2)

<.0001

 Excessive polypharmacy (≥ 10)

49,623

(10.8)

3545

(16.2)

46,078

(10.5)

<.0001

Use of sedative drugs

225,843

(49.0)

13,797

(62.9)

212,046

(48.3)

<.0001

Use of digoxin

6610

(1.4)

406

(1.9)

6204

(1.4)

<.0001

Use of insulin

6077

(1.3)

517

(2.4)

5560

(1.3)

<.0001

Use of warfarin

4278

(0.9)

300

(1.4)

3978

(0.9)

<.0001