Development and Validation of a Carbohydrate and Insulin Dosing Knowledge Quiz in Adults with Diabetes Mellitus

Abstract

Objectives. We aimed to develop and validate a carbohydrate and insulin dosing knowledge quiz for adult Asian patients with diabetes mellitus.

Methodology. A self-administered quiz was developed to test carbohydrate recognition; single food carbohydrate estimation; meal carbohydrate estimation and food label reading; and insulin dosing calculation for carbohydrate, blood glucose and for a meal in a multi-ethnic Asian population. The subjects’ carbohydrate knowledge and insulin dosing ability were rated by the study dietitian and the subjects’ primary physicians, respectively.  We compared the quiz scores with the dietitians’ and physician ratings and the subjects’ HbA1c.  Reliability of the quiz was tested by measuring internal consistency and split half reliability.

Results. Seventy-five subjects completed the study. Median (inter-quartile range) quiz score was 71.9 (60.2 to 83.6)%.  The quiz score was found to be correlated with the health care provider assessments (r=0.652, p<0.001) and the subjects’ HbA1c (r=-0.375, p=0.001).  Cronbach alpha was 0.897 and Guttman split half coefficient was 0.930. 

Conclusions.  Our analysis suggested that this newly developed quiz had good reliability and validity for testing carbohydrate and insulin dosing knowledge in a group of Asian subjects with diabetes mellitus.  This can be a useful screening tool in clinical practice.