Practical skills and comprehensive knowledge are indispensable to benefit from real time continuous glucose monitoring (rtCGM) systems. The German Federal Joint Committee (G-BA) demands a qualified training for rtCGM users. To assess users’ rtCGM-knowledge, a questionnaire based on the independent training program SPECTRUM was developed and evaluated.
Diabetes professionals defined central knowledge content about rtCGM (content validity). They suggested 50 relevant multiple-choice (MC) items with 5 answer options. After a pilot study, the final knowledge questionnaire comprises 40 MC items. This version was answered by adults and adolescents with type 1 diabetes and diabetes professionals.
The total sample (n=233; 70% female) consisted of 111 people with diabetes (mean (SD) age: 42 (14) years, diabetes duration: 20 (14) years, 64% CSII, 38% CGM, HbA1c 8.0 (1.7)%) and 122 diabetes professionals (46 (11) years).
Internal consistency (Cronbach‘s alpha) was 0.92 for the total sample, for people with diabetes 0.94 and for professionals 0.84. Item difficulty ranged from 0.12 to 0.88 for people with diabetes and from 0.27 to 0.97 for professionals.
On average, 24.1 ± 9.9 items were answered correctly by people with diabetes and 29.2 ± 5.2 by professionals (p<0.001). People with diabetes without rtCGM-experiences reached lower values than rtCGM-experienced ones (21.0 ±10.4 vs. 29.2 ± 6.2; p=0.001). Their HbA1c correlated negatively with the sum-score of the questionnaire (r=- 0.36; p<0.001).
The knowledge questionnaire “rtCGM-Profi-Check” showed a good internal consistency and a high content validity. The questionnaire is an objective, reliable and valid measure to assess persons’ knowledge about rtCGM.