The Parent–Infant Interaction Observation Scale: reliability and validity of a screening tool

Background: Sensitive responsiveness in parent–infant interaction is a significant predictor of infant attachment security, but frontline practitioners do not currently have the tools to identify ‘high-risk’ dyads. There is an urgent need for a brief screening tool that can be used by practitioners to screen new parents. Aims: To assess the reliability and validity of the Parent–Infant Interaction Observation Scale (PIIOS) in screening parent–infant interaction at 2–7 months. Method: Twenty-three professionals trained in parent–infant observation rated 14 3-minute videotapes of parent–infant interaction using the PIIOS in two studies. Inter-rater reliability was assessed using intraclass correlation coefficients, and validity was assessed by comparing the CARE-Index Maternal Sensitivity scale with the new scale, with inter-item correlation expressed as mean difference and 95% confidence intervals (CI). Results: The inter-rater reliability was excellent – study 1 0.94 (95% CI 0.92–0.95) and study 2 0.94 (95% CI 0.93–0.95). Higher correlation coefficients were obtained for scores in the lower range. A strong overall correlation coefficient was obtained with the CARE-Index Sensitivity scale – study 1: –0.88, and study 2: –0.86 (p < 0.001), ranging from 0.60 to 0.94 (study 1) and 0.59 to 0.89 (study 2) for individual coders. There was also strong internal consistency with positive correlations between each item score and the total score (range: 0.55–0.87). Conclusion: The PIIOS comprises a brief and easily administered method of screening parent–infant interaction, which could be used by primary care practitioners to identify parents in need of further support.