A systematic review of 14 previous studies found that all had reported a reduction in average blood glucose levels in patients that used an app, compared to those who did not, with an approximate reduction in HbA1c (glycated haemoglobin) of about 0.5%. The analysis also found that younger patients were more likely to report a benefit. No evidence was found to support the use of apps in type 1 diabetes, but further research is needed to substantiate this.