Psychometric properties of Parenting Sense of Competence Scale using item-response theory

Parental competence is one of the essential components of raising ethical and healthy children. The mother's satisfaction with her maternal role significantly influences her cognitive responses and parenting behaviors. Having appropriate instruments to measure maternal satisfaction and identify and solve potential problems after childbirth can substantially contribute to maintaining and improving mother and infant health. This study aimed to evaluate the psychometric properties of the Parenting Sense of Competence (PSOC) Scale in mothers referring to the healthcare centers affiliated with Qazvin University of Medical Sciences. This cross-sectional psychometric study collected data from 254 mothers with 1.5-month-old infants referred to the healthcare centers in Qazvin Province. Data were analyzed using the item response theory (IRT) in SPSS 26 and Stata 17 software. The mean age (±standard deviation) of participants was 30.05 ± 5.7, and the overall Cronbach's alpha for the scale was 0.931. We used the graded response model (GRM) appropriate for Likert-type rating scales to fit the IRT. The discrimination parameter estimates showed that item 5 had a discrimination level <0.65, leading to its exclusion from the final analysis. In addition, the total information index confirmed that the scale was suitable in the trait range of -2.1 to 1.8. Compared with other common models for ordered responses based on general model fit indices, the GRM showed a better fit. The study results recommend applying the IRT models to improve and enhance the quality of questionnaires in various measurement fields.