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Early Intervention and Child Health: Evidence from a Dublin Based Trial Orla Doylea,b, Nick Fitzpatrickb, Judy Lovettc, Caroline Rawdond aUCD School of EconomicsbUCD Geary Institute for Public Policy

Irish Economic Association Annual Conference, 7th May 2015

+Background

Steep socio-economic gradient in health that emerges early in life (Case et al, 2002)

Poor health during childhood associated with adverse educational and labour market outcomes (Case et al., 2005; Currie and Hyson, 1999)

Identifying the causal pathways through which SES is related to child health is limited by endogeneity

+This Study

We utilize a randomized controlled trial, which experimentally modifies the parenting and home environment of disadvantaged families, to investigate a mechanism for ameliorating poor health

Early intervention may be effective from a biological and economic perspective

Home visiting programs (HVPs) target disadvantaged families from pregnancy onwards

Systematic reviews of HVPs report mixed findings on child health Avellar & Supplee (2013): 5 of 12 HVPs identify significant treatment effects Peacock et al. (2013): 2 of 7 HVPs identify significant treatment effects

But none account for small sample size, differential attrition or multiple hypothesis testing

+ Preparing for Life programme One of first & longest running Irish experimental interventions

Aim: Improve child school readiness by assisting parents from pregnancy-age 5

+ Treatment

1. Home-visiting Mentoring Programme

Fortnightly home-visits from a trained mentor from pre-birth to age 5

Mentors role: act as advisors to the participating families & support and educate parents about child development & parenting

Home visits structured around “Tip Sheets” - handouts presenting best-practice information relating to child development

2. Triple P Parenting Programme (Sanders et al., 2003) Promotes healthy parenting practices and positive parent-child

attachment

Group Triple P: 5 two-hour group discussion sessions and 3 phone calls

Offered when their children are between 2 and 3 years old

+ Recruitment & Randomisation

Eligibility Criteria: Cohort of pregnant women residing in catchment area between Jan 2008-

August 2010

Recruitment: Maternity hospital & within the local community (b/w 12-26 weeks) Population-based recruitment rate was 52%

Randomisation: Unconditional probability randomisation strategy

115 allocated to Treatment group 118 allocated to Control group

+ Data & Methodology

Data Baseline data: No statistical differences between treatment and control

groups on 114/126 baseline measures (90.5%)

Outcome data: Maternal reports of child health in previous 6/12 months assessed at 6, 12, 18, 24, and 36 months Child general health Number of health problems which required medical attention Incidences of hospitalization Incidences of accidents which required medical attention Incidences of asthma/wheezing which required medical attention Incidences of chest infections which required medical attention Received necessary immunizations

Methods Permutation based hypothesis testing (Heckman et al. 2010): small sample

inference Stepdown procedure (Romano & Wolf, 2005): multiple hypothesis testing Inverse Probability Weighting: differential attrition/missing data

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+ Attrition

Allocated to Intervention (n = 115)

Allocated to Control (n = 118)

Randomized (n = 233)

Assessed at baseline (n = 104)

Assessed at baseline (n = 101)

Assessed at 24-months (n = 81)

Assessed at 18-months (n = 74)

Assessed at 6-months (n = 83)

Assessed at 6-months (n = 90)

Assessed at 12-months (n = 82)

Assessed at 12-months (n = 83)

Assessed at 18-months (n = 80)

Assessed at 36-months (n = 74)

Assessed at 36-months (n = 76)

Assessed at 24-months (n = 84)

+ Results: IPW-adjusted impact of treatment on Child Health (1)

N (intervention

/control)

Mintervention (SD) Mcontrol (SD) IPW chi-squared/t-test

pa

IPW Permutation Test

pb

IPW Stepdown Permutation Test

pb

Rated Good Health

6 months 173 (83/90) 0.92 (0.27) 0.94 (0.23) 0.580 0.591 0.932

12 months 165 (82/83) 0.94 (0.24) 0.93 (0.26) 0.833 0.841 0.97318 months 154 (80/74) 0.92 (0.27) 0.87 (0.34) 0.322 0.302 0.73124 months 165 (81/84) 0.95 (0.23) 0.84 (0.37) 0.054* 0.037** 0.12436 months 150 (74/76) 0.88 (0.33) 0.89 (0.32) 0.908 0.910 0.910

Number of Health Problems

6 months 173 (83/90) 1.38 (1.73) 1.24 (1.02) 0.414 0.605 0.96312 months 164 (81/83) 1.37 (1.49) 1.39 (1.12) 0.712 0.926 0.99518 months 154 (80/74) 1.42 (1.38) 1.31 (1.24) 0.664 0.651 0.95324 months 165 (81/84) 1.26 (1.31) 1.71 (1.55) 0.257 0.089* 0.27936 months 150 (74/76) 1.42 (1.22) 1.41 (1.24) 0.940 0.942 0.942

Hospital Stay 6 months 173 (83/90) 0.09 (0.29) 0.07 (0.26) 0.632 0.637 0.89512 months 165 (82/83) 0.07 (0.25) 0.07 (0.25) 0.987 0.987 0.98718 months 154 (80/74) 0.01 (0.10) 0.09 (0.28) 0.042** 0.027** 0.18624 months 165 (81/84) 0.04 (0.20) 0.06 (0.24) 0.596 0.581 0.92436 months 150 (74/76) 0.06 (0.25) 0.10 (0.30) 0.425 0.409 0.889

+ Results: IPW-adjusted impact of treatment on Child Health (2)

N (intervention

/control)

Mintervention (SD) Mcontrol (SD) IPW chi-squared/t-test

pa

IPW Permutation Test

pb

IPW Stepdown Permutation Test

pb

Accident

12 months 165 (82/83) 0.04 (0.21) 0.01 (0.10) 0.171 0.154 ~

18 months 154 (80/74) 0.08 (0.27) 0.04 (0.21) 0.387 0.405 ~24 months 165 (81/84) 0.10 (0.30) 0.10 (0.30) 0.955 0.957 ~36 months 150 (74/76) 0.12 (0.33) 0.21 (0.41) 0.162 0.159

Immunizations ~4 months 172 (82/90) 0.97 (0.18) 0.90 (0.31) 0.071* 0.045** 0.2126 months 165 (82/83) 0.98 (0.13) 0.97 (0.18) 0.584 0.597 0.59713 months 154 (80/74) 0.89 (0.32) 0.85 (0.36) 0.526 0.536 0.807

Wheezing or Asthma 12 months 165 (82/83) 0.11 (0.32) 0.10 (0.30) 0.812 0.817 0.99318 months 154 (80/74) 0.17 (0.38) 0.16 (0.37) 0.844 0.846 0.97324 months 165 (81/84) 0.08 (0.28) 0.24 (0.43) 0.019** 0.013** 0.035**36 months 150 (74/76) 0.16 (0.37) 0.17 (0.38) 0.939 0.939 0.939

Chest Infection 12 months 165 (82/83) 0.26 (0.44) 0.43 (0.50) 0.102 0.158 0.21518 months 154 (80/74) 0.29 (0.46) 0.31 (0.47) 0.746 0.750 0.93524 months 165 (81/84) 0.27 (0.45) 0.38 (0.49) 0.134 0.132 0.37536 months 150 (74/76) 0.31 (0.47) 0.33 (0.47) 0.833 0.835 0.835

+ Robustness & Additional Analyses

Conditional permutation testing Given RCT design, conditioning on covariates should not be strictly necessary,

however can improve the precision (Duflo et al., 2006)

Re-estimated results conditioning on significant baseline variables – unconditional and conditional results largely equivalent

Multiple Imputation (MI) as an alternative to IPW IPW and MI results are largely equivalent, with one extra statistically significant

result (number of health problems at 24 months) found in the MI models

Gender differences - effects for boys only Individual effects: Number of health problems at 24 months (d = 0.63), hospital

stays at 18 months (3 pp), accidents at 36 months (23.9 pp), asthma/wheezing at 24 months (22.5 pp), and chest infections at every time point (22.8 – 37.9 pp)

Stepdown effects: number of health problems, accidents, and chest infections

+ Differential misreporting & Contamination

Differential Misreporting Maternal report subject to measurement error if mothers over/under report

their child’s health Tested for differential misreporting using Social Desirability Scale-17 (SDS-17;

Stöber, 2001)

No evidence of differential misreporting

Contamination As potential for contamination in PFL is high, test using a ‘blue-dye’ question Limited evidence of contamination

Mintervention (SD) Mcontrol (SD) IPW-Perm. Test P2

Social Desirability Scale 11.19 (2.77) 11.29 (2.76) 0.540

Mintervention (SD) Mcontrol (SD) IPW Perm. Test P2

Heard the phrase ‘descriptive praise’ & accurately reports how to engage in this behavior

0.26 (0.44) 0.06 (0.24) 0.001

+Conclusion

A bundle of parenting interventions has some positive and statistically significant effects on child health

Binomial test shows probability of observing the number of reported favourable differences by chance is small

Strongest main effect on incidences of wheezing/asthma (15.5 pp reduction)

Effects driven by boys alone – consistent with Campbell et al. (2014) Number of health problems (d = 0.63), accidents (23.9 pp) and chest

infections (22.8 – 37.9 pp) Greater vulnerability of boys in the prenatal and infancy periods

Results robust to small sample size, differential attrition, multiple hypothesis testing, differential misreporting & contamination