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Table 1 Cohort characteristics by overall discretionary screen-time categories

From: Associations of discretionary screen time with mortality, cardiovascular disease and cancer are attenuated by strength, fitness and physical activity: findings from the UK Biobank study

 

Screen-time categories (h.day− 1)

<2

2–3

4–5

>5

Socio-demographics

 Total n

65,374

204,470

95,877

25,368

 Women, n (%)

38,977 (59.6)

110,399 (54.0)

51,460 (53.7)

12,519 (49.4)

 Age (years), mean (SD)

54.0 (8.0)

55.5 (8.1)

57.8 (7.8)

56.8 (8.2)

 Deprivation index quintiles, n (%)

  Lower

22,447 (34.3)

74,332 (36.4)

31,308 (32.7)

6643 (26.2)

  Middle

21,683 (33.2)

70,242 (34.4)

32,612 (34.0)

7515 (29.6)

  Higher

21,244 (32.5)

59,896 (29.3)

31,957 (33.3)

11,210 (44.2)

 Professional qualifications, n (%)

  College or university degree

33,304 (55.8)

72,395 (40.7)

20,217 (28.2)

5872 (33.2)

  A levels/AS levels or equivalent

7943 (13.3)

25,182 (14.2)

9120 (12.7)

2136 (12.1)

  O levels/GCSEs or equivalent

10,408 (17.4)

45,118 (25.4)

23,125 (32.3)

5115 (28.9)

  CSEs or equivalent

2230 (3.7)

11,517 (6.5)

6666 (9.3)

1641 (9.3)

  NVQ or HND or HNC or equivalent

2840 (4.8)

13,182 (7.4)

7388 (10.3)

1881 (10.6)

  Other professional qualifications

2984 (5.0)

10,603 (6.0)

5178 (7.2)

1042 (5.9)

 Income categories, n (%)

  Less than £18,000

7366 (12.8)

28,761 (16.1)

22,871 (28.5)

7808 (36.8)

  £18,000 to £29,999

11,344 (19.7)

44,273 (24.8)

23,569 (29.4)

5047 (23.8)

  £30,000 to £51,999

15,613 (27.1)

52,221 (29.3)

19,823 (24.7)

4066 (19.2)

  £52,000 to £100,000

16,782 (29.2)

42,731 (24.0)

11,718 (14.6)

3277 (15.4)

  Greater than £100,000

6432 (11.2)

10,364 (5.8)

2180 (2.7)

1025 (4.8)

 Employment status, n (%)

  In paid employment or self-employed

48,674 (75.2)

134,628 (66.4)

46,746 (49.2)

11,612 (46.3)

  Retired

11,970 (18.5)

56,500 (27.9)

40,443 (42.6)

9862 (39.3)

  Looking after home and/or family

2194 (3.4)

5578 (2.8)

2701 (2.8)

681 (2.7)

  Unable to work because of sickness or disability

722 (1.1)

2180 (1.1)

2310 (2.4)

1605 (6.4)

  Unemployed

662 (1.0)

2435 (1.2)

2117 (2.2)

1089 (4.3)

  Doing unpaid or voluntary work

344 (0.5)

907 (0.5)

378 (0.4)

117 (0.5)

  Full-time or part-time student

203 (0.3)

522 (0.3)

256 (0.3)

112 (0.5)

 Ethnicity, n (%)

  White

60,997 (93.3)

193,700 (94.7)

90,686 (94.6)

23,229 (91.6)

  South Asian

1806 (2.8)

4095 (2.0)

1580 (1.7)

622 (2.5)

  Black

1072 (1.6)

2994 (1.5)

1935 (2.0)

854 (3.4)

  Chinese

267 (0.4)

721 (0.4)

312 (0.3)

108 (0.4)

  Mixed background / others

1232 (1.9)

2960 (1.5)

1364 (1.4)

555 (2.2)

 Smoking status, n (%)

  Never

41,168 (63.2)

118,540 (58.2)

50,242 (52.6)

12,551 (49.7)

  Previous

18,901 (29.0)

67,082 (32.9)

34,420 (36.0)

8815 (34.9)

  Current

5087 (7.8)

18,207 (8.9)

10,870 (11.4)

3889 (15.4)

Obesity-related markers

 BMI, mean (SD)

25.7 (4.2)

27.1 (4.5)

28.2 (4.8)

28.89 (5.4)

 BMI categories, n (%)

  Underweight (< 18.5)

566 (0.9)

952 (0.5)

280 (0.3)

107 (0.4)

  Normal weight (18.5–24.9)

31,288 (48.1)

70,487 (34.6)

24,335 (25.5)

5781 (23.0)

  Overweight (25.0 to 29.9)

24,428 (37.5)

88,950 (43.7)

42,855 (44.9)

10,374 (41.3)

  Obese (≥30.0)

8788 (13.5)

43,274 (21.3)

27,941 (29.3)

8875 (35.3)

 Waist circumference (cm), mean (SD)

85.3 (12.3)

89.2 (12.9)

92.2 (13.3)

94.38 (14.2)

 Central Obesity, n (%)

13,362 (20.5)

60,575 (29.7)

37,674 (39.4)

11,327 (44.9)

 % Body fat, mean (SD)

29.2 (8.3)

30.8 (8.4)

32.7 (8.4)

32.89 (8.9)

Fitness, Physical activity and Sleep, mean (SD)

 Fitness (METs)

9.7 (3.5)

9.2 (3.4)

8.3 (3.3)

8.3 (3.5)

 Grip strength (kg)

31.1 (10.7)

31.5 (11.0)

30.4 (11.2)

30.5 (11.3)

 Total physical activity (MET.h.week−1)

6.6 (8.9)

6.7 (9.2)

6.3 (9.1)

5.0 (7.8)

 TV viewing (h.day−1)

0.7 (0.4)

2.3 (0.7)

4.1 (0.9)

5.3 (2.4)

 PC screen time (h.day−1)

0.8 (0.4)

1.0 (0.8)

1.3 (1.4)

3.0 (3.1)

 Screen time (h.day− 1)

1.6 (0.6)

3.4 (0.9)

5.4 (1.2)

8.2 (2.0)

 Sleep duration (h.day−1)

7.1 (0.9)

7.1 (1.0)

7.2 (1.1)

7.1 (1.2)

Dietary intake, mean (SD)

 Total energy (kcal.day−1)

2124.2 (636.5)

2115.3 (634.9)

2111.3 (660.9)

2126.5 (736.9)

 Protein intake (% of TE)

15.3 (3.4)

15.6 (3.6)

15.7 (3.8)

15.6 (4.0)

 Carbohydrates intake (% of TE)

47.7 (8.1)

47.1 (8.1)

47.0 (8.2)

46.9 (8.6)

 Total Fat intake (% of TE)

31.9 (6.6)

32.0 (6.7)

32.2 (6.8)

32.4 (7.1)

 Saturated intake (% of TE)

12.2 (3.3)

12.3 (3.3)

12.4 (3.4)

12.5 (3.5)

 Sugar intake (% of TE)

22.8 (6.9)

22.4 (6.9)

22.3 (7.1)

22.2 (7.5)

 Alcohol intake (% of TE)

5.1 (6.2)

5.3 (6.4)

5.2 (6.7)

5.0 (7.0)

 Red meat intake (portions.week−1)

1.8 (1.4)

1.9 (1.4)

2.0 (1.5)

2.1 (1.7)

 Processed meat intake (portions.week−1)

1.7 (1.1)

1.9 (1.1)

2.0 (1.1)

2.0 (1.1)

 Vegetable and Fruit intake (grams.day−1)

350.7 (196.9)

331.3 (189.1)

316.7 (192.7)

308.8 (213.5)

 Oily fish (portions.week−1)

1.1 (1.1)

1.1 (1.0)

1.1 (1.0)

1.0 (1.1)

Health status

 Diabetes history, n (%)

1784 (2.7)

7493 (3.7)

5411 (5.7)

2097 (8.3)

 High blood pressure history, n (%)

11,565 (17.7)

47,541 (23.3)

28,760 (30.1)

8281 (32.8)

 Systolic blood pressure (mmHg), mean (SD)

135.7 (19.4)

139.6 (19.5)

142.6 (19.5)

141.6 (19.8)

 Diastolic blood pressure (mmHg), mean (SD)

80.6 (10.7)

82.4 (10.6)

83.5 (10.5)

83.6 (10.8)

 Medication for cholesterol or blood pressure, n (%)

  None of the above

60,310 (92.3)

184,387 (90.2)

82,102 (85.6)

21,719 (85.6)

  Cholesterol-lowering medication

2259 (3.5)

9644 (4.7)

7267 (7.6)

2037 (8.0)

  Blood pressure medication

2805 (4.3)

10,439 (5.1)

6508 (6.8)

1612 (6.4)

  1. BMI body mass index, MET metabolic equivalent, SD standard deviation, TE total energy intake