Development Of The Dietary Management Scale For Type 2 Diabetes Mellitus Patients

Objective: To develop a scale of dietary management ability for type 2diabetes mellitus patients, which is suitable for our country’s diet culture, and to examine the items and factors of the scale,and to test the reliability and validity of the scale.Methods:(1) The study is based on the theory of “Knowledge-attitude-practice pattern” of health promotion.(2) The pretesting scale is formed through the following methods: concept definition,review of the relevant literature, referring to evidence-based guideline of diabetes,semi-structural interview of patients, and experts consultation method. Then the initial scale with three factors and 28 items is formed after the pre-survey.(3) Totally 334 patients were investigated using the initial scale. Survey data was input into SPSS19.0 software after checking. The items were analyzed and screened by the following methods: item analysis method, variation coefficient method, the critical ratio method, Pearson correlation coefficients, Cronbach a coefficient method, principal component analysis method and exploring factor analysis. The reliability analysis methods include homogeneity reliability, split-half reliability and test-retest reliability. The validity analysis was evaluated by surface validity, content validity and construct validity.Results:(1) Through concept definition, reference literature review and evidence-based guidelines, combined with interviews, the scale with three dimensions and 27 items was formed.(2) A item was added and 20 items were modified after two rounds of expert consultation. The initial scale includes three dimensions and 28 items.(3) Items and factor analysis results: 28 items were analyzed by item analysis andexploratory factor analysis. A total of 13 items were deleted. The formal scale includes three dimensions and 15 items: diabetes diet knowledge(7 items), diabetes diet beliefs(4items), diabetes diet behavior(4 items).(4) Reliability test:(1)The Cronbach a coefficient of total scale is 0.815, three dimensions’ Cronbach a coefficient are 0.739, 0.885 and 0.616 respectively.(2)The parity binary coefficient of the total scale is 0.861, and 0.731, 0.900, 0.646 of the three dimensions respectively.(3)The test-retest reliability of the whole scale is 0.814, the three dimensions are 0.859, 0.833,0.917 respectively. All of the coefficients were statistically significant(P<0.000).(5) Validity test:(1)The surface validity: According to the theory and method of scale development, and our knowledge reserves, the scale showed good surface validity.(2)Content validity: The total scale content validity index(CVI) was 0.893, and each item ranges from 0.87~1.0.(3)Construct validity: There are three factors extracted by exploratory factor analysis, which explained 51.475% variances, and meeting requirements of greater than 40%. The load coefficient for all items are greater than 0.45. The final scale model is consistent with the theory of construction, and the structure validity is reliable.Conclusion: The dietary management scale for type 2 diabetes mellitus patients is proved to be a reliable and valid tool which can reflect the ability of dietary management correctly and scientifically. The scale content conforms to our country’s social and cultural background and the features of patients’ dietary management. The scale can be used to measure the patients’ dietary management ability, and provide reference for in-depth research.