Psychometric evaluation of a modified food security survey scale in the economically deprived population of Hong Kong

Abstract

Food security is vital for global health and sustainable development. However, existing validated versions of the Household Food Security Survey Module (HFSSM) cannot address the needs for a shorter Chinese version with a shorter reference period. This study aimed to examine the psychometric properties of a 6-item Chinese-version of the HFSSM (3-month reference period), among the economically deprived population in Hong Kong. This study included 512 observations from community-dwelling Chinese adults (≥ 18 years), who were social services users or food assistant service applicants, and with household income < 75% of the population median. Construct validity and scale targeting were assessed using Rasch analysis. Convergent validity, known-group validity, internal consistency, and test-retest reliability were also examined. The construct validity was satisfactory, with a logical item calibration hierarchy and good infit statistics for five items (0.81–1.26), although a floor effect was indicated in the Wright map. The convergent validity was supported through a moderate positive correlation with the single-item household food insufficiency scale (r = 0.58). Known-group validity showed higher scores among those aged < 65 years (d = 1.17, p < 0.001), living with children aged < 18 years (d = 1.09, p < 0.001), enrolled in the food assistance program (d = 0.54, p < 0.001), living at the poverty line or below (d = 0.30, p = 0.010), and with poor or fair health (d = 0.20, p = 0.028). Furthermore, the scale had fair-to-good internal consistency (Cronbach’s alpha = 0.88, Rasch person reliability = 0.64) and excellent test-retest reliability (ICC = 0.96) in one week. The 6-item Chinese-version of the HFSSM (3-month reference period) is a valid and reliable measure of household food insecurity in the economically deprived population in Hong Kong.