Validation and application of the Insulin Treatment Appraisal Scale in Cuban patients with type 2 diabetes mellitus

The purpose of this study was to validate the Insulin Treatment Appraisal Scale (ITAS) in the Cuban population with type 2 diabetes mellitus.

A cross-sectional, multicentre analytical study was performed in Cuba from February 2020 to April 2021; 199 patients were surveyed in a hospital institution and in primary healthcare. We used the Insulin Treatment Appraisal Scale, consisting of 20 items, with a minimum score of 20 points and a maximum of 100, where the higher the score, the worse the perception of insulin therapy. The validity of the instrument was determined by means of an exploratory factor analysis. The internal consistency and reliability of the scale were calculated by means of Cronbach's alpha coefficient. A K-means cluster analysis was performed to establish a cut-off point for poor perception of insulin therapy.

The exploratory factor analysis supported the validity of the instrument, with a Cronbach's alpha of 0.747. There were statistically significant differences between patients under insulin and non-insulin treatment in terms of the answers given in all items of the scale. The total mean score obtained was 51.96 ± 10.78, and it was lower in insulin users compared to those who used other drugs (49.79 ± 10.07 vs 55.09 ± 11.12). A score ≥65 was proposed as a cut-off point for poor perception of insulin therapy. A positive relationship was found between the body mass index values and the total score of the scale. Being female and current treatment not involving insulin were factors associated with low perception of insulin therapy.

The instrument proved to be valid for the population in which it was applied. Insulin users turned out to be the ones with the best perception about its use. A cut-off point of ≥65 points for poor perception of insulin treatment was proposed for evaluation and comparison in future studies in other patient populations.