A Questionnaire for User Satisfaction Standardized for CGM Performance Evaluation Studies (QUSS-CGM): Development and first validation steps

Background and aims: The management of glucose concentrations is part of the daily routine for people with diabetes, which has been eased with the development of new technologies, such as continuous glucose monitoring (CGM). A crucial factor for the acceptability of such devices is user friendliness and user satisfaction, aspects that are often assessed through questionnaires in CGM performance studies. Nonetheless, there is a lack of standardized questionnaires explicitly designed for CGM performance evaluation studies, which makes it hard to contrast study outcomes. This work focuses on the development and first validation steps of a Questionnaire for User Satisfaction Standardized for CGM Performance Studies (QUSS-CGM).

Methods: From a systematic literature search of studies evaluating CGM performance covering the years from 2002 to 2023, initial attributes were described, which defined the content of the items constituting the questionnaire. The validation process started with the content validation, in which a group of experts (n=9) in the diabetes technology field rated the items according to their relevance and clarity. After applying corresponding content changes, a group of people with diabetes (n=10) rated the comprehensibility of the remaining items through the response process validation (face validity).

Results: From the systematic literature search, 205 items (including duplicates) were gathered and classified into six defined attributes: sensor handling, comfort, reliability, ease of use, experience and digital interface. The grouped items were highly repetitive; therefore, they were summarized in a 25-item draft questionnaire. Through content and face validation, a pre-validated questionnaire constituted of 21 items and rated with a 5-point Likert scale, referred to as pre-QUSS-CGM, reflected a scale-level content validity index of 0.90 and a scale-level face validity index of 0.93 (from a maximum score of 1), thus indicating an acceptable content and face validity.

Conclusion: The validation steps presented here resulted in the pre-QUSS-CGM, which is planned for final validation including descriptive statistics and psychometric evaluation within a CGM performance evaluation. The development and validation of the QUSS-CGM seeks to establish a standardized instrument to assess user satisfaction in CGM performance studies. This questionnaire might therefore become complementary to a performance evaluation standard for CGM devices.

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Artikel online veröffentlicht:
18. April 2024