Psychometrics of the NICHD Scales to inform clinical practice

Kyla Vaillancourt^1*Kim Alyousefi-van Dijk^2,3Jane Barlow⁴Lydia Barge²Harshita Kavia²Camilla Rosan^2,5Helen Sharp⁶Susan Ayers¹

• ¹City St George's University of London School of Health & Medical Sciences, London, United Kingdom
• ²Anna Freud Centre, London, United Kingdom
• ³Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom
• ⁴Department of Social Policy and Intervention, University of Oxford, Oxford, United Kingdom
• ⁵University College London, London, United Kingdom
• ⁶Department of Primary Care and Mental Health, University of Liverpool, Liverpool, United Kingdom

Background: There is no recommended measure of parent-infant interaction that is psychometrically robust, feasible (i.e., brief and simple to use) and validated for use from birth to 12 months for routine use in Perinatal Mental Health Services (PMHS). This study tested the cross-sectional construct validity of the global sensitivity scale and a sensitivity composite from the NICHD Parent-Infant Interaction scales in a clinical sample of parents and babies, and the inter-rater reliability of all the NICHD scales in a sub-sample of dyads with infants under 3 months of age. Methods: Secondary analysis using parent-infant interaction videos from a Randomised Controlled Trial in specialist PMHS in England were used. Participants were 275 dyads who completed baseline self-reports (parental mental health symptoms, parent-reported bonding) and parent-infant observation tasks where sensitivity was measured (free play, book sharing, clothing change). Parents with infants over 2 months of age (N=180), also completed measures of child development. Non-parametric correlations and linear regression were conducted to assess construct validity and intra-class correlations were conducted to evaluate inter-rater reliability. Results: Amongst dyads with infants 0-3 months, inter-rater reliability was good for the global and composite sensitivity scale, but poor-to-moderate for the scales of parental intrusiveness, dyadic mutuality and the infant scales. In the full sample of dyads, there was a small but significant negative association between the global and composite sensitivity scales and parental mental health symptom severity, but this association was not statistically significant when sensitivity was observed in the free play alone. In terms of child development, greater sensitivity was only associated with fewer socio-emotional problems when it was observed during the clothing change task. There was a statistically significant negative association between observed sensitivity and bonding difficulties, and the strength of this association was greater for younger infants than older infants. Conclusions: These findings contribute to the evidence base of the NICHD scales in a PMHS setting and suggest ways that the clinical utility of the NICHD scales could be improved for routine practice. Abbreviations: NICHD=National Institute for Child Health and Development