Validation of General Nutrition Knowledge Questionnaire for Adults in Uganda

Abstract

Knowledge is a significant component of several behavioral theories used in nutrition, including the health belief and stages of change models. In Uganda, the evaluation of nutrition interventions is limited by the lack of validated tools, especially of nutrition knowledge. The objective in this study was to validate (i.e. construct validity and reliability) a general nutrition knowledge questionnaire (GNKQ) for adults in Uganda.A revised version (i.e. after expert review and face validation) of the GNKQ comprised 47 questions grouped in five domains assessing knowledge on recommendations (4), food groups (17), food choices (10), nutrition and disease relationship (11), and food fortification (5). A purposive sample of teachers (n=40) from Kampala and students (n=77) from Makerere University was recruited to complete the GNKQ twice, at least within one week apart. Students completed the questionnaire using the Qualtrics online platform; while the head teachers completed the GNKQ by hand. Item difficulty (acceptable range: 0.1–0.9) and discrimination analyses (acceptable above 0.2) were applied to data to remove simple and complex items, and those that failed to predict scores within each of knowledge domains. After removing the items, the questionnaire remained with a total of 28 questions with 89 items. Before deletion of any items, we assessed the internal consistency (Cronbach α), the content validity (Student t‐test) and test‐retest reliability for all subjects and each sub‐population group. The overall Cronbach alpha (all groups) was 0.93 and 0.94 at the first and second round, respectively. This was 0.84 and 0.85 for the head teachers and 0.94 and 0.95 for the students, at the first and second round, respectively. Overall internal consistencies for the following domains were considered acceptable (i.e. 0.70–0.95), food groups (0.81 and 0.81), nutrition and disease relationship (0.78 and 0.84), and food fortification (0.94 and 0.94) in the first and second rounds, respectively. For nutrition recommendations and food choices the internal consistencies were below 0.7. The overall test‐retest reliability using Pearson correlation was 0.89. The Pearson correlation coefficients were 0.93 and 0.63 for students and head teachers, respectively. The overall nutrition knowledge scores of nutrition students (104.8), engineering students (71.8) and head teachers (76.2) were significantly different (P<0.05). Trends and differences in knowledge scores remained similar after the second round of the questionnaire, 106.7, 72.0, and 79.7, respectively. Overall findings showed that the GNKQ is valid and reliable to evaluate nutrition knowledge among adults in Uganda. Low internal consistencies for some dimensions require continuous review of specific items. Further studies will address test‐retest reliability of the GNKQ using a larger population sample.Support or Funding InformationUSAID Borlaug Higher Education for Agricultural Research and Development (BHEARD) Program fellowship. Margin of Excellence funds from the Division of Nutritional Sciences at the University of Illinois Urbana‐Champaign (UIUC). UIUC Graduate College's Focal Point ‐UCOUNT project.