Reliability and validity of nutrition knowledge questionnaire for adults

Abstract

Objective: To determine the validity and reliability of a nutrition knowledge questionnaire for adults in California.

Methods: A convenience sample of adults was recruited for cognitive interviews. A mail-based survey of 400 randomly selected addresses was used to assess internal consistency (Cronbach α). Researchers assessed content validity (Student t test) and test-retest reliability (Pearson correlation) in a convenience sample of university students who had previously taken a college nutrition course, compared with students who had not.

Results: Twenty adults participated in cognitive interviews, 94 adults returned the mailed questionnaire, and 48 university students participated in validity and reliability testing. Cronbach α = .91 and test-retest r = 0.95, demonstrating internal consistency reliability and test-retest reliability. Students who had taken a college-level nutrition course scored significantly higher compared with students who had not (P < .001), demonstrating construct validity.

Conclusions and implications: Findings show that the questionnaire is a valid and reliable nutrition knowledge measure for use in California and may be of use in other places.

Keywords: nutrition knowledge; questionnaires; validated instruments.