Time trends in family risks and their impact

1. Time trends in family risks and their impact Stephan Collishaw & Barbara Maughan MRC SGDP Centre Institute of Psychiatry King’s College London

2. Time trends in family risks Recent decades • Marked changes in family demographics • age at marriage / cohabitation • age at birth of first child • family size • partnership stability / breakdown • complexity of family forms • Increases in psychosocial disorders among young people

3. Time trends in adolescent conduct problems1974-1999 Collishaw et al, 2004

4. Questions • do changing family patterns ‘explain’ trends in child outcomes? • do the same risk factors contribute to • individual differencesin behaviour problems? • overall levelsof behaviour problems? • does theimpactof family risks change when their prevalence changes?

5. Divorce rate per 1,000 married population1961-1999 (England & Wales) ONS Population Trends 102, 2000 &Social Trends 20, 1990

6. Hypothesis • increasing prevalence of divorce associated with reduction in impact • pre-divorce ‘selection’ effects • less troubled families • less parental discord • post-divorce consequences • less social stigma • increased awareness of impact for children

7. Parental divorce and child outcomesmeta analysis (Amato, 2001) Decade of publication

8. Parental divorce and child outcomesmeta analysis (Amato, 2001) Decade of publication

9. UK CohortsEly et al, 1999; Sigle-Rushton et al, 2005 Cohort

10. Possible explanations • change in nature of marital dissolution • ‘low discord’ divorce especially distressing for children • increasing gap in economic well-being • single-parent families not benefited from economic expansion

11. Aims • update picture to include more recent cohort • examine 3 family indicators • family type • family income • family size • explore changes in prevalence and impact • illustrate changes in correlates • test how far changing family risks ‘account for’ rising levels of conduct problems

13. Samples Age 16

14. Measures Family-based correlates Family type (single vs. step vs. intact) Family income (<60% median vs. remainder) Family size (4+ children vs. 1-3 children) Adolescent conduct problems fighting bullying stealing lying disobedience

15. Divorce rate per 1,000 married population1961-1999 (England & Wales) Cohort 3 Cohort 2 Cohort 1 ONS Population Trends 102, 2000 &Social Trends 20, 1990

16. Teenagers living with both birth parents

17. Teenagers living in a step-family

18. Teenagers living in single-parent households

19. Low income by cohort: intact families

20. Proportion of families in poverty: Single parent vs. intact families Single Intact

21. Increasing income-inequality: single parent vs. intact families OR = 8.5 Single Intact

22. Increasing income-inequality: single parent vs. intact families OR = 8.5 OR = 10.1 Single Intact

23. Increasing income-inequality: single parent vs. intact families OR = 8.5 OR = 10.1 OR = 19.4 Single Intact

24. Family type and conduct problems by cohort OR = 1.9 Family type

25. Family type and conduct problems by cohort OR = 2.1 OR = 1.9 Family type

26. Family type and conduct problems by cohort OR = 1.8 OR = 2.1 OR = 1.9 Family type

27. Family type and conduct problems by cohort OR = 2.7 Family type

28. Family type and conduct problems by cohort OR = 2.2 OR = 2.7 Family type

29. Family type and conduct problems by cohort OR = 1.6 OR = 2.2 OR = 2.7 Family type

30. Summary: family type Risk factor Exposure ‘Impact’ Single parent family Up No change Step family Up Down?

31. Absolute household disposable income in the UK (1974-1999) Social Trends, 2002

32. “Relative poverty” in the UK (1974-1999) Social Trends, 2006

33. “Relative poverty” by study cohort

34. ‘Relative poverty’ and conduct problems by cohort Low income OR = 1.4

35. ‘Relative poverty’ and conduct problems by cohort OR = 2.1 Low income OR = 1.4

36. ‘Relative poverty’ and conduct problems by cohort OR = 1.7 OR = 2.1 Low income OR = 1.4

37. Family size by cohort: % four or more children

38. Family size and conduct problems by cohort OR = 3.0 N children

39. Family size and conduct problems by cohort OR = 2.3 OR = 3.0 N children

40. Family size and conduct problems by cohort OR = 1.8 OR = 2.3 OR = 3.0 N children

41. Summary of findings up to now Risk factor Exposure ‘Impact’ Single parent family Up No change Step family Up Down? ‘Relative poverty’ No change Up Large family size Down Down

42. Conduct problems: high scores Total OR = 1.56 per cohort

43. What contributes to time trends in conduct problems?

44. What contributes to time trends in conduct problems?

45. What contributes to time trends in conduct problems?

46. What contributes to time trends in conduct problems?

47. Some conclusions • 1. Parallel trends in risks and outcomes do not imply a causal link • Increase in divorce rate over the past 30 years • Increase in conduct problems over the same time period • However, trends in family type appear largely independent of trends in conduct problems

48. Some conclusions • 2. Correlates of risk factors may change over time • E.g. Amato • Only had limited data with which to look at this • Socio-economic disadvantage even more strongly associated with single parenthood in more recent cohorts

49. Some conclusions • 3. Implication: changes in impact of a risk factor as important as changes in exposure • Focus on changes in exposure insufficient • Also need to consider possible change in association between risk and outcome • E.g. 1: family type and conduct problems; impact the same or reduced over time • E.g. 2: relative poverty and conduct problems; impact gone up over time

50. Some conclusions. • 4. Different explanatory models needed for understanding individual differences and level differences • Family type, income and size all associated with CP at individual level • But, trends in these aspects of family life only made modest contribution to understanding of level differences • Different factors may be relevant for the two