Table 1 Background characteristics from the mid-adulthood spirometry assessment.

From: Lung function in adults born with very low birth weight from young to mid-adulthood

 

1. BPD-VLBW

2. Non-BPD-VLBW

3. (all) VLBW

4. Term (reference)

p-value between 1 and 4

p-value between 2 and 4

p-value between 3 and 4

Number of participants

20

95

115

142

   

HeSVA

16

61

77

83

   

NTNU

4

34

38

59

   

Maternal background characteristics

Mean (SD) or n (%)

Mean (SD) or n (%)

Mean (SD) or n (%)

Mean (SD) or n (%)

   

Maternal age (years)

29.5 (5.5)

30.2 (4.5)

30.1 (4.7)

30.05 (4.8)

0.66

0.84

0.98

Height (cm)

163.9 (7.3)

165.2 (6.0)

165.0 (6.2)

166.1 (5.6)

0.15

0.27

0.16

Smoking during pregnancya

2 (20.0%)

12 (26.1%)

14 (25.0)

11 (16.9)

0.81

0.24

0.27

Parental educational attainment

    

0.73

0.11

0.12

Basic or less

4 (21.1%)

19 (20.4%)

23 (20.5%)

15 (11.5%)

   

Upper secondary

4 (21.1%)

15 (16.1%)

19 (17.0%)

28 (21.4%)

   

Lower-level tertiary

5 (26.3%)

32 (34.4%)

37 (33.0%)

37 (28.2%)

   

Upper-level tertiary

6 (31.6%)

27 (29.0%)

33 (29.5%)

51 (38.9%)

   

Study participant characteristics

       

Sex, women

12 (60.0%)

56 (58.9%)

68 (59.1%)

82 (57.7%)

0.84

0.85

0.82

Gestational age (weeks)

27.5 (2.5)

29.8 (2.3)

29.4 (2.5)

40.1 (1.2)

<0.001

<0.001

<0.001

Birth weight (g)

997 (261)

1207 (193)

1171 (220)

3653 (481)

<0.001

<0.001

<0.001

Birth weight SD score Finnish reference

−0.87 (1.20)

−1.33 (1.69)

−1.24 (1.6)

0.14 (1.0)

0.001

<0.001

<0.001

Birth weight SD score Norwegian reference

−0.67 (0.90)

−1.09 (1.17)

−1.02 (1.1)

0.05 (1.0)

0.002

<0.001

<0.001

C-section as a delivery mode

8 (40.0%)

66 (70.2%)

74 (64.9%)

11 (13.3%)

0.010

<0.001

<0.001

Ventilator treatment (days)

32.3 (21.5)

3.3 (4.4)

8.2 (14.5)

-

-

-

-

Supplemental oxygen (days)

72.7 (84.3)

11.8 (15.3)

21.9 (42.8)

-

-

-

-

Age at discharge from hospital (days)

105.9 (82.2)

61.7 (20.5)

70.7 (44.2)

-

-

-

-

Bronchopulmonary dysplasia diagnosed by clinician

20 (100%)

-

20 (25.0%)

-

-

-

-

RDS

18% (90.0%)

37 (39.8%)

55 (48.7%)

-

-

-

-

Study participant mid-adulthood assessment characteristics

       

Age (years)

36.3 (2.7)

36.1 (3.4)

36.1 (3.3)

35.8 (3.3)

0.48

0.24

0.36

Height, cm

164.0 (9.9)

168.9 (9.5)

168.0 (9.7)

173.7 (9.6)

<0.001

<0.001

<0.001

BMI (kg/m2)

27.4 (6.9)

25.7 (5.66)

26.0 (5.89)

25.7 (4.41)

0.29

0.91

0.58

Daily smoking

0 (0)

13 (14.0%)

13 (11.5%)

15 (10.6%)

0.04

0.43

0.81

Never smoked vs. others

14 (70.0%)

51 (54.8%)

65 (57.5%)

71 (50.0%)

0.09

0.47

0.23

Current use of inhaled glucocorticoids or adrenergic bronchodilators

4 (20.0%)

17 (17.9%)

21 (12.8%)

12 (8.5%)

0.12

0.03

0.02

History of asthma (treated or diagnosed by a physician)

4 (20.0%)

27 (28.4%)

31 (27.0%)

30 (21.1%)

1.0

0.20

0.28

Respiratory symptoms in the last 12 months

8 (40.0%)

32 (34.4%)

40 (35.4%)

44 (31.0%)

0.42

0.67

0.46

Educational attainment

    

0.14

0.003

0.049

Lower (ISCED levels 1–2)

0 (0)

3 (3.2%)

3 (2.6%)

2 (1.4%)

   

Intermediate (ISCED levels 3–5)

11 (55%)

43 (45.3%)

54 (47.0%)

47 (33.1%)

   

Lower tertiary or higher (ISCED levels 6–8)

9 (45.0%)

49 (51.6%)

58 (50.4%)

93 (65.5%)

   
  1. BPD bronchopulmonary dysplasia, BMI body mass index, HeSVA Helsinki study of very low birth weight adults, ISCED International Standard of Classification of Education, NTNU NTNU low birth weight in a lifetime perspective study, SD standard deviation, VLBW very low birth weight.
  2. aData available only for HeSVA participants.