Numeracy Skills and Glycemic Control in an Observational, Multicenter, Cross-Sectional, and International Study of Children with Type 1 Diabetes

Aims: This study examined the possible association between numeracy skills and glycemic outcomes in children with type 1 diabetes. Methods: The study used a cross-sectional design and collected data from 7 centers of the Hvidoere Study Group. HbA1c was measured centrally. Numeracy was assessed using the specific 5-item Diabetes Numeracy Test (DNT-5) and the international, general Wordless Mathematical Test (WMT). The HbA1c predictive multivariate generalized linear model was constructed using the adjusted R-squared index for model selection. Pearson’s correlation coefficient was calculated between observed and predicted HbA1c levels in the training and testing datasets. Results: Overall, 306 adolescents aged 12-18 (mean age 14.96 ± 1.68) years and diabetes duration of 6.57 (±3.75) participated in this study. Numeracy skills, as assessed by the WMT but not DNT-5, predicted the HbA1c levels after adjustment for sociodemographic and clinical factors. The correlation between observed and predicted HbA1c levels was consistent in both datasets and was 0.34 (N = 155) and 0.37 (N = 61) for the training and test datasets, respectively (p = 0.412). The effect size for the WMT-based predictive model of HbA1c adjusted for clinical and socioeconomic factors was significantly higher (p < 0.05) than the single-parameter-based model. Conclusions: Numeracy, as assessed by an international general math test, is a good predictor of HbA1c in children and adolescents with type 1 diabetes. The basic and short WMT is a potentially effective tool in personalized clinical pediatric diabetes practice. Therapy planning should consider adjusting therapy to compensate for lower numeracy skills and/or training to improve the patient’s numerical proficiency.