Abstract
Background: The H & H Lactation (H & H) scale is a useful instrument for understanding mothers' perceptions of insufficient milk supply, which is the common reason given for premature cessation of breastfeeding. This instrument may be used to intervene in postbirth dropoff in breastfeeding among mothers.
Objectives: To examine construct and nomological validity and related psychometric evidence for the translated H & H scale using a repeated measurement design in a sample of Thai mothers.
Method: A repeated measurement design with 196 mother-infant dyads. Data were collected at two time periods. At Time 1, data on the H & H and Index of Breastfeeding Status (IBS) scales were obtained between 36 and 48 hr postbirth. For Time 2, the same mothers completed the same instruments at 1 month postbirth. Psychometricproperties of the H & H scale were examined using convergent, discriminant, and nomological validity principles with instructural equation modeling.
Results: Based on judgment/classification task, exploratory/confirmatory factor analysis, and cross-validation using multisample analysis, only nine items of the H & H scale measured at Time 1 and Time 2 were found to be psychometrically sound for measuring insufficient milk supply for Thai mothers. An analysis of the influence of the nine-item of the H & H scale measured at Time 1 and Time 2 on the IBS measured at Time 2 showed that (a) the direct effects of two subscales of the H & H scale measured at Time 2 on the IBS were significant and positive, providing support for the nomological validity of the H & H scale; (b) each H& H factor at Time 1 had a significant influence on its corresponding factor at Time 2, supporting convergent validity; and (c) the crossover effects for each H & H factor for Time 1 and Time 2 data were nonsignificant, indicating discriminant validity.
Discussion: Overall, the 20-item H & H scale appears to be unreliable and invalid for measuring the concept of insufficient milk supply in cross-cultural studies. However, the short form of nine items is reliable and valid for Thai mothers. Further testing and development of the H & H scale and the proposed short form in other cultures and contexts is warranted.