1. Effect of Concurrent, Lagged, and Cumulative Exposure to Poverty on Children’s Health from 5- through 41 Months Béatrice Nikiéma, Lise Gauvin, Louise Séguin & Maria Victoria Zunzunegui 12 th World Congress on Public Health, Istanbul, April 2009

2. Introduction  Poverty-health links are often studied  Dynamics of poverty across time and its relationship with health outcomes  More limited data  Even fewer data among young children, across the early childhood years  Lesser quantity of data on physical health

3. Objective  To examine how different durations and timing of adverse economic circumstances are related to the likelihood of experiencing childhood physical health problems

4. Data The Québec Longitudinal Study of Child Development (QLSCD)  A birth cohort, coordinated by the Direction Santé Québec of the Institut de la statistique du Québec since 1998  A representative sample of 2120 singleton live births registered in the Québec live births registry in 1997-1998  Data collection: 5 months + annual follow-up  By face to face interviews with parents (98% mothers)  Hospital records for data on neonatal conditions

5. Data  The four first waves of data  Participation rate at baseline  5 months : 83% n =2120  Participation at follow-up:  17 months : 96 %, n= 2045  29 months : 94 %, n= 1997  41 months : 92 %, n= 1950

6. Health Indicators  Number of asthma attacks during the previous 12 months  Number of acute infections during the previous 3 months

7. Defining Poverty  Child Poverty : Living in a household with insufficient income  Before taxes annual income falls below the Low Income Cut-Off (LICO) from Statistics Canada

8.  Concurrent Poverty : poverty measured synchronously with the assessment of the health outcome  Lag of Poverty : poverty status recorded at the previous measurement occasion  Cumulative Poverty : total number of measurement occasions during which a child was deemed to be living in conditions of poverty Defining Poverty

9. Analytic Strategies Effects of Concurrent Poverty or Lagged Poverty (1)  Multilevel Models for Count Data (Poisson regression)  Growth Curve Analysis  2 Hierarchical Levels Level 1=measurement occasion ; Level 2=children  Laplace Approximation (Laplace6)

10. Analytic Strategies Effects of Cumulative Poverty (2)  Multilevel Multivariate Response Analysis  Level 1: health outcome at each measurement occasion  Level 2: Children  Separate fixed effects at each occasion  Accounting for within-occasion variance and between-occasion covariance

11. Results

12. Prevalence of Health Problems

13. Prevalence of Insufficient Income used as a proxy of Poverty

14. Concurrent Effects of Poverty # of Asthma Attacks 1 # of Acute Infections 2 Event Rate Ratio (95% CI) Event Rate Ratio (95% CI) Change due to concurrent poverty Income sufficient1.00 Income insufficient 1.11(0.94-1.31)1.04(0.97-1.11) 1 Adjusted for child’s sex and birth rank, type of family, and mother’s age and education; 2 Adjusted for child’s sex, use of daycare center, and mother’s education and immigration status; * p <.05; ** p <.01

15. Lagged Effects of Poverty 1 Adjusted for child’s sex and birth rank, type of family, and mother’s age and education; 2 Adjusted for child’s sex, use of daycare center, and mother’s education and immigration status; # Asthma Attacks 1 # Acute Infections 2 Event Rate Ratio (95% CI) Event Rate Ratio (95% CI) Change due to poverty at the previous measurement occasion Income sufficient1.00 Income insufficient1.28(1.10-1.50)1.10(1.02-1.18)

16. Cumulative Effects of Poverty 17 months29 months41 months Event Rate Ratio # of Asthma Attacks 1 # periods with insufficient income None1.00 11.712.14*1.38 21.77*2.28*1.34 32.32*2.66* 42.90* # of acute infections 2 # periods with insufficient income None1.00 11.181.141.05 21.091.121.07 31.161.13 41.09 1 Adjusted for child’s sex and birth rank, type of family, and mother’s age and education; 2 Adjusted for child’s sex, use of daycare center, and mother’s education and immigration status * p<0.5

17. Summary Concurrent Effect Lagged Effect Cumulative Effect # Asthma Attacks - ++ # Acute Infections - +-

18. Conclusion (1)  Our results support the hypotheses that :  Exposure to poverty may result in health problems at a later time Poverty recorded at the previous measurement occasion is associated with current health outcomes  Accumulation of poverty insults may result in greater risk of health problems among young children Association between greater number of periods spent living in poverty & greater number of asthma attacks

19. Conclusion (2)  Timing & duration of poverty matter for child physical health  Further investigation warranted  With continuous indicator of poverty or material deprivation (?)  For the effect of income instability (social mobility)

20. Acknowledgements  The study was funded by the Canadian Institutes of Health Research Grant #200309MOP-123079 and Grant #200609MOP-165867  The Institut de la Statistique du Québec, Direction Santé Québec who was responsible for the data collection and validation.  Lise Gauvin holds a Canadian Institute for Health Research / Centre de Recherche en Prevention de l’Obésité Applied Public Health Chair in Neighborhoods, Lifestyle, and Healthy Body Weight.  The GRIS and the CRCHUM receive infrastructure funding from the Fonds de la recherche en santé du Québec (FRSQ)  The Léa-Roback Research Center is funded through a Research Center development initiative by the Canadian Institutes of Health Research.