Development and validation of a Weight-Specific Health Literacy Instrument (WSHLI)

Abstract

Objective: Develop/validate a weight-specific health literacy instrument.

Methods: The development of weight-specific health literacy measurement consisted of seven phases: (a) a literature review; (b) consultation with weight management experts; (c) generation of an item pool; (d) selection of items via the Delphi method; (e) pilot testing; (f) a national survey; and (g) examination of the psychometric properties of the results.

Results: A random sample of 362 Taiwanese adults completed the face-toface survey. The results of factor analysis indicated reasonable good fit of a 2-factor model (χ²/df=1.1, p=0.18; RMSEA=0.02, CFI=0.99, TLI=0.99). Construct validity testing showed that the both factors were significantly correlated with s-MHLS (γ=0.71, p<0.001; γ=0.22, p<0.001), comprehension (γ=0.32, p<0.001: γ=0.10, p<0.05), and writing (γ=0.44, p<0.001: γ=0.11, p<0.05). Predictive validity testing showed that the first factor had significant correlations with weight management efficacy (γ=0.16, p<0.001), and three weight management behaviors. The second factor was significantly correlated with weight management efficacy (γ=0.11, p<0.05) but not with the 3 weight management behaviors.

Conclusions: On the basis of the psychometric results, we conclude that the final version of Weight-Specific Health Literacy Instrument (WSHLI) includes the 13 items. It is a valid and reliable tool for weight management research and evaluation in Mandarin Chinese speaking populations.

Keywords: Health literacy; Scale development; Weight management; Weight-Specific Health Literacy Instrument (WSHLI).