Parent-reported sleep problems in relation to respiratory health in 11-year-old children born extremely preterm† in Norway during 1999 and 2000
| Difficulty falling asleep or frequent awakenings | Snoring | Daytime sleepiness | Not recommended sleep duration‡ | |||||||||
| No (n=144) % (n) | Yes (n=54) % (n) | Adjusted§ (n=146–197) OR (95% CI) | No (n=144) % (n) | Yes (n=56) % (n) | Adjusted§ (n=148–199) OR (95% CI) | No (n=165) % (n) | Yes (n=34) % (n) | Adjusted§ (n=147–198) OR (95% CI) | No (n=104) % (n) | Yes (n=33) % (n) | Adjusted§ (n=95–136) OR (95% CI) | |
| Last 12 months at 11 years age¶ | ||||||||||||
| Wheezing (yes) | 17.3 (18) | 32.6 (14)* | 2.1 (0.9 to 4.9) | 20.8 (22) | 27.9 (12) | 1.4 (0.6 to 3.3) | 17.8 (21) | 40.0 (12)** | 3.4 (1.4 to 8.3) | 13.9 (10) | 29.2 (7) | 2.5 (0.8 to 8.1) |
| Number of attacks last 12 months** | ||||||||||||
| None | 0 (0) | 21.4 (3) | 13.6 (3) | 9.1 (1) | 4.8 (1) | 27.3 (3) | 10.0 (1) | 33.3 (2) | ||||
| 1–3 | 52.9 (9) | 57.1 (8) | 59.1 (13) | 45.5 (5) | 61.9 (13) | 36.4 (4) | 50.0 (5) | 50.0 (3) | ||||
| >4 | 47.1 (8) | 21.4 (3) | 27.3 (6) | 45.5 (5) | 33.3 (7) | 36.4 (4) | 40.0 (4) | 16.7 (1) | ||||
| Disturbed sleep due to wheezing (yes)†† | 6.8 (7) | 16.3 (7) | 2.6 (0.8 to 8.1) | 7.6 (8) | 14.0 (6) | 1.8 (0.6 to 5.8) | 6.0 (7) | 20.0 (6)* | 3.9 (1.2 to 13.0) | 1.4 (1) | 16.7 (4) | §§ |
| Wheeze during or after exercise (yes) | 15.5 (22) | 22.2 (12) | 1.4 (0.6 to 3.2) | 12.6 (18) | 29.1 (16)** | 2.8 (1.3 to 6.1) | 14.1 (23) | 32.4 (11)* | 2.9 (1.2 to 6.8) | 12.9 (13) | 15.2 (5) | 1.0 (0.3 to 3.3) |
| Dry cough at night (yes) | 15.4 (22) | 20.4 (11) | 1.4 (0.6 to 3.2) | 13.9 (20) | 25.5 (14) | 2.1 (0.9 to 4.6) | 15.9 (26) | 23.5 (8) | 1.6 (0.7 to 4.0) | 10.7 (11) | 12.5 (4) | 1.2 (0.4 to 4,2) |
| Currently at 11 years age | ||||||||||||
| Current asthma (criteria-based)‡‡ | 18.2 (26) | 20.8 (11) | 1.1 (0.5 to 2.5) | 11.9 (17) | 36.4 (20)*** | 4.2 (1.9 to 8.9) | 17.2 (28) | 29.4 (10) | 1.9 (0.9 to 4.7) | 9.8 (10) | 21.2 (7) | 2.6 (0.9 to 7.6) |
| Asthma medication use | ||||||||||||
| Inhaled corticosteroids or oral leukotriene modifiers | 8.3 (12) | 16.7 (9) | 2.3 (0.9 to 5.9) | 8.3 (12) | 17.9 (10) | 2.4 (0.9 to 5.9) | 8.5 (14) | 23.5 (8)* | 3.4 (1.3 to 9.0) | 3.8 (4) | 18.2 (6)* | 5.6 (1.5 to 21.9) |
| Inhaled bronchodilators | 9.0 (13) | 14.8 (8) | 1.9 (0.7 to 5.1) | 7.6 (11) | 19.6 (11)* | 3.2 (1.3 to 8.2) | 8.5 (14) | 23.5 (8)* | 3.9 (1.4 to 10.9) | 5.8 (6) | 15.2 (5) | 3.4 (0.9 to 12.6) |
*p≤0.05, **p≤0.01, ***p≤0.001 (χ2 test or Fisher’s exact test). Boldface denotes significant group differences.
†Gestational age <28 weeks or birth weight <1000 g.
‡Not recommended sleep duration at 11 years was defined as <9 hours.
§Logistic regression: adjusted for sex, single parenthood and maternal education (dichotomised as less than a 3-year college education or not).
¶The International Study of Asthma and Allergies in Childhood questionnaire.
**The response options to the number of attacks were ‘none’, ‘1–3’, ‘4–12’ and ‘more than 12’. We merged the answer ‘4–12’ attacks and ‘more than 12’ attacks to ‘>4’ attacks.
††The response option was; ‘never woken’, ‘less than one night per week’ and ‘one or more nights per week’. In our analyses, the answers ‘less than one night per week’ and ‘one or more nights per week’ were merged into a yes.
‡‡Current asthma was defined as yes to ‘ever asthma’ combined with either respiratory symptoms or use of asthma medication in the previous 12 months, or asthma medication and symptoms in the past 12 months regardless of reporting asthma.
§§Adjusted analyses not performed due to low number.
¶¶