Refusal of insulin therapy results in an average of a year’s delay for patients with type 2 diabetes to achieve glycaemic control, compared with those who accept their doctor’s advice, a US study shows.

Harvard University-led investigators looked at patient records at two large Boston hospitals between 2000 and 2014 and found that 43% of 5300 people with diabetes (and HbA1c above 53mmol/mol) declined their doctor’s first recommendation to use insulin.

Their study is one of the first to examine the effects of refusing the therapy, the authors say.

Among patients declining insulin, the mean time to achieving an HbA1c level below 53mmol/mol was 50 months, while it was just 38 months for those who followed doctors’ advice.