Further Development and Validation of the Affordances in the Home Environment for Motor Development–Infant Scale (AHEMD-IS)

Abstract

Background Affordances in the home environment may play a significant role in infant motor development. Objective The purpose of this study was to further develop and validate the Affordances in the Home Environment for Motor Development–Infant Scale (AHEMD-IS), an inventory that measures the quantity and quality of motor affordances in the home. Design A cross-sectional study was conducted to evaluate criteria for content validity, reliability, internal consistency, floor and ceiling effects, and interpretability of the instrument. Methods A pilot version of the inventory with 5 dimensions was used for expert panel analysis and administered to parents of infants (N=419). Data were analyzed with Cronbach alpha, intraclass correlation coefficients (ICCs), ceiling and floor effects, and item and dimension interpretability analyses for creation of a scoring system with descriptive categories for each dimension and total score. Results Average agreement among the expert panel was 95% across all evaluation criteria. Cronbach alpha values with the 41-item scale ranged between .639 and .824 for the separate dimensions, with a total value of .824 (95% confidence interval [95% CI]=.781, .862). The ICC values were .990 for interrater reliability and .949 for intrarater reliability. There was a ceiling effect on 3 questions for the Inside Space dimension and on 3 questions for the Variety of Stimulation dimension. These results demonstrated the need for reduction in total items (from 41 to 35) and the combination of space dimensions. After removal of questions, internal consistency was .766 (95% CI=.729, .800) for total score. Overall assessment categories were created as: less than adequate, moderately adequate, adequate, and excellent. Limitations The inventory does not determine specific use (time, frequency) of affordances in the home, and it does not account for infants' out-of-home activities. Conclusions The AHEMD-IS is a reliable and valid instrument to assess affordances in the home environment that promote infant motor development.