Table 1 Seasonal average study population (#) and percentage (%) by age group and high-risk conditions, Denmark (2010/11 to 2017/18) and England (2010/11–2018/19).

From: The feasibility of pragmatic influenza vaccine randomized controlled real-world trials in Denmark and England

 

Denmark

England

Age group:

 

18–34 yrs

35–49 yrs

50–64 yrs

65–74 yrs

>75 yrs

18–34 yrs

35–49 yrs

50–64 yrs

65–74 yrs

>75 yrs

Study population

#

1,184,338

1,162,715

1,091,518

607,953

422,744

2,124,434

1,932,551

1,641,127

810,820

703,539

No high-risk condition

#

1,116,222

1,048,161

888,877

418,772

240,462

1,770,594

1,451,475

1,031,906

395,988

259,218

%

94.3

90.1

81.4

68.9

57.0

83.3

75.1

62.9

48.8

36.8

Any high-risk condition

#

68,116

114,554

202,642

189,182

182,282

353,840

481,076

609,221

414,832

444,320

%

5.7

9.9

18.6

31.1

43.0

16.7

24.9

37.1

51.2

63.2

Asthma

#

9424

10,298

9990

5943

4181

149,687

152,166

137,866

73,471

61,578

%

0.8

0.9

0.9

1.0

1.0

7.0

7.9

8.4

9.1

8.8

Respiratory disorders

#

1303

4329

15,975

20,205

24,617

1716

7642

37,639

48,471

52,624

%

0.1

0.4

1.5

3.3

5.8

0.1

0.4

2.3

6.0

7.5

Cardiovascular

#

3959

17,050

58,372

72,192

95,037

4812

18,310

74,855

97,262

168,364

%

0.3

1.5

5.3

11.9

22.4

0.2

0.9

4.6

12.0

23.9

Diabetes

#

10,027

26,678

69,683

67,618

51,795

19,534

56,832

137,204

116,557

121,541

%

0.8

2.3

6.4

11.1

12.2

0.9

3.0

8.4

14.4

17.3

Endocrine disorders*

#

7455

14,029

16,489

10,800

10,628

18,516

38,451

52,165

33,277

35,860

%

0.6

1.2

1.5

1.8

2.5

0.9

2.0

3.2

4.1

5.1

Blood disorders

#

476

488

716

953

1476

3584

2914

1591

696

787

%

0.0

0.0

0.1

0.2

0.4

0.2

0.2

0.1

0.1

0.1

Immunocompromised

#

11,361

23,440

47,006

51,182

45,635

32,523

37,212

54,186

53,220

62,564

%

1.0

2.0

4.3

8.4

10.7

1.5

1.9

3.3

6.6

8.9

Kidney disorders

#

840

1,918

4046

5792

9513

1735

6964

26,055

46,062

100,293

%

0.1

0.2

0.4

0.9

2.2

0.1

0.4

1.6

5.7

14.2

Liver disorders

#

1849

4276

6517

3043

1177

3226

10,620

16,654

7704

3319

%

0.2

0.4

0.6

0.5

0.3

0.2

0.6

1.0

0.9

0.5

Neurological disorders

#

1498

3730

5462

5748

13,106

1331

3924

7279

11,354

52,003

%

0.1

0.3

0.5

0.9

3.1

0.1

0.2

0.4

1.4

7.4

  1. *Excludes diabetes.