1. Timing of exposure to poverty and occurrence of asthma attack in the Quebec Longitudinal Study of Child Development
Louise Séguin, Maria-Victoria Zunzunegui, Lise Gauvin, and Béatrice Nikiéma.
Department of Social and Preventive Medicine
Université de Montréal
12th World Congress on Public Health
Istanbul, April 2009

2. Child Poverty and Health
Links between child poverty and health are well known.
Mechanisms underlying these links are not fully understood in industrialized countries.
Poverty during early childhood might have long term consequences for later health.

3. Our study
In our study we examined the links between timing and duration of child poverty and child asthma attacks when children were 6-7 years old.

4. Duration/timing of poverty and child health
Long term or chronic poverty has more impact on a child health than transitory poverty (Spencer, 2000, Séguin et al, 2005, 2007)
Some authors demonstrated that if a child grew up in a low SES family during his/her first 2 years of life, that child was more likely to experience a chronic illness at 10-11years old. (Chen et all, 2008)

5. Child Poverty and Adult Health
Child poverty during early childhood not only affects child health, it also jeopardizes future adult health independently of adult socioeconomic status.

6. Child Poverty and Adult Health
An adult who experienced early childhood poverty has a higher risk of:
Early mortality (Kuh, 2002; Claussen, 2003, Galobardes, 2008)
Cardiovascular diseases (Barker, 1992; Barker, 2001)
Type 2 diabetes (Lawlor, 2002)
Cognitive development problems (Richards, 2002; Yeung, 2002; Cheung, 2001; Guo, 2000)
Older age cognitive problems (Stern, 1994; Abbott, 1998; Kaplan, 2001)

7. Child poverty in Canada
Children are the age group most often affected by poverty in Canada.
Canada has higher child poverty rates than many Europeans countries

8. Child Poverty in Industrialized Countries – UNICEF 2007

9. Defining poverty Poverty:
Absolute or relative lack of material resources
Poverty is not only about lack of money or insufficient income
Lack of money determines and limits choices of resources
Being poor involves being exposed to multiple adversities.

10. Pediatric asthma
Asthma is one of the most frequent health problem among young children in industrialized countries
Poor children are disproportionnately burdened by asthma (Chen et al,, 2006; Lindbaek, et al,, 2003; Séguin et al, 2007).
There are still controversies and uncertainties concerning the factors that are involved with pediatric asthma (Wright & Subramania, 2007; Lougheed, 2007),

11. Objectives of the study
The objectives of this study are to examine:
if the presence of asthma attack is related to the timing and duration of poverty among 5 to 7 years old children from the QLSCD.
the role of exposure to cumulative adversities before 4 years old in the occurrence of asthma attack among these 5 to 7 years old children.

12. The Quebec Longitudinal Study of Child Development (QLSCD)
Sampling from the Quebec live births records
By the Direction Santé Québec of the Quebec Institute of Statistics.
A representative cohort of 2120 singleton live births in Quebec excluding those
residing in the Northern Quebec, Cree, and Inuit regions, and on Indian reserves
for whom duration of gestation is unknown.
with a gestational age <24 wks or >42 wks

13. The Quebec Longitudinal Study of Child Development (QLSCD): data sources
Birth data were extracted from hospital charts.
Health conditions at birth (birth weight, gestational age, congenital malformations,...)
Data were collected annually at home by interviewers. Mothers were respondents in 97-99% of cases
Mothers completed self-administered questionnaires.

14. Participation rates
Annual follow-up of 2120 children who were 5 months old in 1998 (initial participation rate: 83%)
Participation rate at follow-ups:
1 yr ½ : 96 %, n= 2045
2 yrs ½ : 94 %, n= 1997
3 yrs ½ : 92 %, n= 1950
4 yrs : 92 %, n= 1944
5 yrs : 83 %, n= 1759
6 yrs : 70,4%, n= 1492
7 yrs : 75,9%, n= 1528

15. Measure of poverty
Poverty was defined as having a household income before taxes (previous 12 months) below the Low-Income Cut Offs (LICO) from Statistics Canada.
Computation of the LICO takes into account the number of persons in the household and the number of residents in a rural or urban area.

16. Measure of asthma attacks
Mother reported if the child experienced an asthma attack during the previous 12 months.
Since we looked at the answers provided during two observation periods, when the child was 6 and 7 years old, in fact we are examing the presence of an asthma attack during the period between 5 and 7 years old.

17. Index of vulnerability/adversity
Index of biological vulnerability at birth:
Being male, 2nd born or more, preterm.
Index of psychosocial adversity <4 years old:
Single parent family, dysfonctional family, maternal depression, low social support, neighborhood perceived as unsafe by the mother.

18. Results

19. Timing and duration of poverty for 6-7 years old children of the QLSCD
No episodes of poverty (1064)
Poor before 4 yrs old only (223)
Poor between 5 to 7 yrs only (70)
Poor <4 yrs + between 5 to7 yrs (253)

20. Chronic Poverty before 4 Years Old and Exposure to Adversity, QLSCD
Adversities
Never
poor
n=1263
Chronic
poverty
n=264
Single parent family
4.9%
36.6%
Dysfunctional family (highest quartile)
21.0%
37.9%
Maternal depression
19.7%
46.4%
Neighborhood perc’ved unsafe by mother
8.3%
24.6%

21. Frequency of asthma attack according to some characteristics of the child, QLSCD

22. Asthma attacks according to timing of poverty and exposure to adversity, QLSCD
Timing of poverty
(low income)
Never
<4 yrs
at 5-7 yrs
< 4 yrs & %
Parent asthma
Mother or father
12.8
15.2
14.3
14.2
Psychosocial adversity < 4 yrs old
Score 0
55.5
23.8
48.6
15.0
Score 1
29.2
34.5
22.8
28.1
Score 2
10.9
18.6
28.8
Score 3-5
4.4
17.9
10.0

23. Multivariate analysis
Logistic regressions
Examining potential interactions between poverty and biological vulnerability or psychosocial adversity regarding asthma attacks among children.

24. Multivariate analysis
The multivariate model is adjusted for:
exposure to smoke from tobacco at home
living in presence of a pet at 5-months old
duration of breastfeeding
the mother’s educational level
No interactions were demonstrated.

25. Probability of an asthma attack between 5 and 7 yrs old, QLSCD Odds ratios (OR)* and 95 % confidence interval (CI)
OR*
95% CI
Timing of poverty
No episode of poverty (ref)
1.0
Poor <4yrs old only
0.8
( )
Poor at 5-7 yrs old only
2.3
( )
Chronic poverty
1.8
( )
Biological vulnerability (ref=0)
Score = 1
1.4
( )
Score = 2-3
1.7
( )
Psychosocial adversity (ref=0)
Score 1
0.9
( )
Score 2
1.1
( )
Score 3-5
( )
Asthma in mother or father (ref=no)
Oui
2.4
( )

26. Conclusions The adjusted model shows that:
The probability of an asthma attack between 5 and 7 years old is higher among children who are poor chronically and among those who are poor at this age compare to those who were never poor.
A history of asthma among parents is associated with a higher probability of a child asthma attack.

27. Conclusions
Early poverty (<4yrs old or < 2 yrs old) is not associated with the occurrence of an asthma attack between 5 and 7 years old.
Actual and chronic poverty appear as the most important.
However, early poverty might show an impact on health during adolescence and adulthood.

28. Conclusions
While their gradient is in the expected direction, the cumulative biological or psychosocial risk factors are not associated with the occurrence of an asthma attack between 5 and 7 years old when family poverty is accounted for.
The link between poverty and child asthma attack is present whatever the level of education of the mother.

29. Limitations of the study
Small number of participants.
Lack of information on:
severity of the disease,
exposure to other risk factors
management and treatment of asthma.

30. Strenghts of the study A longitudinal prospective design
Large participation rates
Data collected annually at home
trained interviewers
validated scales.

31. Future research Other studies are necessary to clarify
The mediating or modifying roles of exposure to diverse psychosocial risk factors regarding the likelihood of an asthma attack among poor children.
At what age early poverty might demonstrate its impact on one’s health

32. Acknowledgments
The study was funded by the Canadian Institutes of Health Research Grant #200309MOP and Grant #200609MOP
The Institut de la Statistique du Québec, Direction Santé Québec was responsible for the data collection and validation of the data base.
The GRIS receives infrastructure funding from the Fonds de la recherche en santé du Québec (FRSQ)