Is numeracy a barrier to glycaemic control in Type 1 diabetes mellitus? A synthesis of current literature

Aims: Healthcare professionals rely on patients’ health literacy and numeracy when providing education to enable self-management of diabetes. We review existing evidence for the impact of health literacy and numeracy on self-care processes in adults with Type 1 diabetes mellitus (T1DM). Methods: A systematic review and narrative synthesis was performed. Four electronic databases were searched from inception to October 2015. Inclusion criteria included at least 70% adults (>17 years old) T1DM population, measurement of health literacy or numeracy with validated score and measure of self-care. Results: A total of 972 articles were identified. Three articles met the inclusion criteria. There was heterogeneity of the studies although all studies used glycaemic control as the primary outcome. Six themes were identified, in particular, the association between numeracy and glycaemic control (p = 0.004, p = 0.066) in T1DM. No association was seen with health literacy. Conclusions: Low numeracy appears to be associated with poorer glycaemic control in adults with T1DM, likely reflecting the skills needed for conventional insulin dose adjustment in T1DM. This review calls for more work to investigate this association further, aid identification and produce strategies to overcome low numeracy.