Background and aims The quality of father-infant interaction impacts on infant developmental outcomes and is increasingly targeted for intervention. Review of the literature reveals few measures to assess the quality of parent-infant interaction during a structured task. Studies exploring the quality of fathers’ interactions have to date, only used the costly and time-consuming Nursing Child Teaching Assessment Scale (NCATS) to rate father-infant interaction. This study aims to explore the reliability and validity of the ORSPI as a measure of the quality of father-infant interaction.

Method Videotapes of 152 five-month old and 74 eight-month old father-infant dyads interacting during a structured task were rated using the 8 item ORSPI scale (scores range from 1–15). Total ORSPI scores were correlated with previously rated NCATS scores. Internal consistency and intra-rater reliability of the ORSPI were also assessed.

Results ORSPI scores were significantly positively correlated with NCATS total caregiver scores for five-month dyads (r=0.513, p<0.001) and eight-month dyads (r=0.634, p<0.001) indicating good concurrent validity. The ORSPI had excellent intra-rater reliability (ICC=0.931) and satisfactory internal consistency (five-month old dyads: Cronbach’s alpha=0.522; eight-month old dyads: Cronbach’s alpha=0.590). Father-infant dyads rated at both five and eight months old (N=74) showed that scores decreased significantly over time Wilcoxon signed rank test (ORSPI: Z= –2.277, p=0.023; NCATS Z= –3.059, p=0.002).

Conclusions The ORSPI has good concurrent validity, correlating with the highly regarded NCATS, and was both easy to use and reliable. These findings support its use as a simple measure of the quality of father-infant interaction.