Background
Methods
Study population
Assessment of main exposure
Assessment of other covariates
Outcome ascertainment
General symptoms
| Rectal hyper-/hypothermia |
Behavioral changes | |
Turning pale or blue or losing consciousness when crying | |
Becoming floppy and no longer eating or dozing | |
Unpleasant odor | |
Suffers a fall | |
Feeding problems
| Coughing/choking/breathing difficulties while suckling |
Regurgitation long after suckling | |
More liquid and more frequent stools | |
Signs during sleep
| Turns pale or blue |
Respiratory arrest or frequent pauses or breathing difficulties | |
Havy sweating | |
Unpleasant smelling sweat | |
Noisy breathing or snoring without having a cold |
Statistical analysis
Complete cases[a] | Incomplete cases[a] | ||
---|---|---|---|
Variable | % (n) | % (n) | P-value[b] |
Gender
|
0.30
| ||
Male |
50.4 (28897)
|
50.9 (10898)
| |
Female |
49.6 (28393)
|
49.2 (10532)
| |
Child’age (months)
|
<0.001
| ||
6-8 |
45.8 (26232)
|
44.9 (9257)
| |
9-10 |
51.6 (29556)
|
51.9 (10694)
| |
11-12 |
2.6 (1502)
|
3.2 (651)
| |
Birth weight
|
0.02
| ||
<2500 g |
6.8 (3880)
|
7.3 (1529)
| |
≥ 2500 g |
93.2 (53410)
|
92.7 (19569)
| |
Mother’s age at childbirth in years
|
<0.001
| ||
< 18 |
1.02 (586)
|
1.16 (239)
| |
18/37 |
92.4 (52932)
|
91.4 (18899)
| |
≥38 |
6.6 (3772)
|
7.5 (1551)
| |
Mother’s level of education
|
<0.001
| ||
< lower secondary education |
8.9 (5127)
|
11.3 (930)
| |
Complete lower secondary education |
18.1 (10382)
|
16.5 (1355)
| |
Complete upper secondary education |
34.7 (19861)
|
30.4 (2488)
| |
Complete higher education/academic or not |
38.3 (21920)
|
41.7 (3419)
| |
Mother’s French language level
|
<0.001
| ||
None |
2.9 (1672)
|
5.8 (1186)
| |
Basic |
5.6 (3192)
|
10.4 (2129)
| |
Proficient |
91.5 (52426)
|
83.8 (17093)
| |
Exclusive breastfeeding
|
<0.001
| ||
Never breastfed |
24.9 (14245)
|
28.1 (5349)
| |
Breastfed for some time |
70.1 (40159)
|
65.7 (12522)
| |
Still breastfed |
5.0 (2886)
|
6.2 (1183)
| |
Smoking daily in the house (2006-2009)
|
<0.001
| ||
Yes |
21.9 (6328)
|
24.0 (2522)
| |
No |
78.1 (22567)
|
76.0 (7981)
| |
Family structure
| |||
Separated parents/sees only one parent |
6.6 (3370)
|
6.6 (1373)
| |
Parents together |
93.4 (53520)
|
93.4 (19345
|
0.8
|
Frightening symptoms (2006-2009) n = 28174 | Polysomno-graphy ordered (2006-2009) n = 30675 | Abnormal polysomno-graphy (2006-2009) n = 2406 | Home monitoring (2006-12) n = 49275 | Psychomotor delay (2006-2012) n = 55180 | BMI < p3 / ≥ p3- ≤97 (thinness) (2006-2012) n = 50810 | BMI > 97 / ≥ p3- ≤97 (overweight) (2006-2012) n = 53978 | |
---|---|---|---|---|---|---|---|
Variables | % | % | % | % | % | % | % |
Mother’s age at birth (years)
| |||||||
≥ 38 | 5.3 | 10.9 | 9.4 | 3.5 | 1.7 | 0.9 | 8.8 |
18-37 | 4.3 | 8.8 | 21.8 | 2.9 | 1.6 | 0.9 | 6.7 |
< 18 | 6.3 | 9.1 | 25.3 | 3.6 | 2.1 | 1.2 | 7.5 |
P-value[a] | 0.06 | 0.6 | 0.2 | 0.08 | 0.583 | 0.3 | 0.03 |
Mother’s level of education
| |||||||
Higher education | 3.7 | 8.8 | 22.8 | 3.3 | 1.4 | 1.0 | 4.6 |
Upper secondary education | 1.4 | 9.1 | 20.4 | 2.9 | 1.5 | 0.9 | 7.0 |
Lower secondary education | 5.4 | 9.4 | 21.9 | 3.0 | 1.7 | 0.7 | 8.8 |
< lower secondary education | 5.0 | 7.0 | 26.8 | 3.0 | 2.6 | 1.0 | 10.7 |
P-value[a] | < 0.001 | 0.02 | 0.3 | 0.9 | < 0.001 | 0.1 | < 0.001 |
Mother’s French language level
| |||||||
Proficient | 4.6 | 9.5 | 21.8 | 3.1 | 1.6 | 0.9 | 6.4 |
Basic | 2.2 | 2.7 | 28.3 | 1.3 | 1.4 | 0.4 | 10.9 |
None | 2.7 | 1.6 | 44.4 | 1.3 | 2.3 | 0.9 | 10.2 |
P-value[a] | < 0.001 | < 0.001 | 0.2 | < 0.001 | 0.067 | 0.01 | < 0.001 |
Child’s gender
| |||||||
Female | 4.2 | 8.6 | 20.4 | 2.8 | 1.5 | 1.1 | 5.5 |
Male | 4.6 | 9.2 | 23.2 | 3.1 | 1.8 | 0.7 | 7.9 |
P-value[a] | 0.1 | 0.6 | 0.09 | 0.06 | 0.004 | < 0.001 | < 0.001 |
Child’s age (months)
| |||||||
6-8 | 4.3 | 8.8 | 21.4 | 2.9 | 1.4 | 0.9 | 6.5 |
9-10 | 4.4 | 9.0 | 22.1 | 3.0 | 1.8 | 0.9 | 6.9 |
11-12 | 4.1 | 9.1 | 24.1 | 3.4 | 2.6 | 1.2 | 6.8 |
P-value[a] | 0.8 | 0.8 | 0.8 | 0.3 | <0.001 | 0.3 | 0.2 |
Birth weight
| |||||||
≥2500 g | 3.2 | 7.4 | 19.1 | 2.1 | 1.4 | 0.8 | 6.9 |
<2500 g | 21.2 | 29.5 | 32.2 | 14.4 | 4.0 | 2.3 | 4.6 |
P-value[a] | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 |
Exclusive Breastfeeding
| |||||||
Some time and still breastfed | 2.8 | 4.9 | 31.2 | 2.2 | 1.4 | 0.8 | 9.9 |
Some time | 3.8 | 8.2 | 21.1 | 2.6 | 1.4 | 0.9 | 6.5 |
Never | 6.3 | 11.6 | 22.6 | 4.2 | 2.2 | 1.0 | 6.8 |
P-value[a] | < 0.001 | < 0.001 | 0.1 | < 0.001 | < 0.001 | 0.3 | < 0.001 |
Smoking in the house (
2006-09
)
| (n = 28147) | (n = 27547) | (n = 2167) | (22868) | (n = 27962) | (n = 25693) | (n = 27310) |
No | 3.8 | 8.4 | 20.8 | 2.8 | 1.4 | 0.9 | 6.4 |
Yes | 6.2 | 10.4 | 21.9 | 3.8 | 2.0 | 0.9 | 8.1 |
P-value[a] | < 0.001 | < 0.001 | 0.6 | < 0.001 | <0.001 | 1.0 | < 0.001 |
Ethics approval
Results
Frightening symptoms (2006-2009)[a]n = 31409 | Polysomnography ordered (2006-2009)[a]n = 30675 | Abnormal Polysomnography (2006-2009)[b]n = 2406 | Home monitoring (2006-12)[a]n = 49275 | Psychomotor delay (2006-2012)[a]n = 55180 | BMI < p3: thinness (2006-2012)[b]n = 50810 | BMI > 97 :overweight (2006-2012)[c]n = 53978 | |
---|---|---|---|---|---|---|---|
Family structure
| |||||||
Parents separated | 6.4% (n = 2174) | 10.5% (n = 2127) | 31.8% (n = 192) | 4.2% (n = 3255) | 2.3% (n = 3624) | 0.7% (n = 3279) | 8.8% (n = 3573) |
Parents together | 4.2% (n = 29235) | 8.7% (n = 28548) | 21.0% (n = 2214) | 2.9% (n = 46020) | 1.6% (n = 51556) | 0.9 %(n = 47531) | 6.6% (n = 50405) |
Crude OR (IC95 %) | 1.5 (1.3-1.8) | 1.2 (1.1-1.4) | 1.8 (1.3-2.4) | 1.5 (1.2-1.8 | 1.4 (1.1-1.8) | 0.7 (0.5-1.1) | 1.4 (1.2-1.6) |
P-value[d] | < 0.001 | 0.005 | < 0.001 | < 0.001 | 0.002 | 0.13 | < 0.001 |
Adjusted OR (IC95%) | 1.4 (1.1-1.6) | 1.1(0.9-1.3) | 1.8 (1.3-2.4) | 1.3- (1.1-1.6) | 1.3 (1.0-1.6) | 0.7 (0.5-1.1) | 1.2 (1.0-1.3) |
P-value[e] | 0.001 | 0.12 | < 0.001 | 0.006 | 0.049 | 0.13 | 0.012 |
AR% | 26 (10.7 to 38.6) | 8.3 (-6.4 to 21.0) | 44 (23 to 58) | 22.5 (6.5 to 35.5) | 21.0 (0.1 to 37.6) | −39 (-112 to 9) | 14.5 (3.3-24.2) |
P-value - GOF test | 0.13 | 0.30 | - | 0.21 | 0.61 | - | <0.001 |