Indications and efficacy of continuous subcutaneous insulin infusion (CSII) therapy in Type 1 diabetes mellitus: a clinical audit in a specialist service

Abstract

To determine if current guidelines correctly identify patients who will benefit from continuous subcutaneous insulin infusion (CSII) therapy by comparing outcomes between Type 1 diabetic patients with recurrent severe hypoglycaemia (SH) indications with those without; and between patients without and with classic contraindications to CSII managed in a single multidisciplinary pump clinic. Changes in biomedical outcomes [glycated haemoglobin (HbA1c), hypoglycaemia, diabetic ketoacidosis (DKA) rates], from before CSII to the end of the study (median duration 20.5 months, range 1-192), were analysed retrospectively from data collected from notes and interviews of 40 patients. Quality of life was assessed by three validated questionnaires at study end (33 patients). Twenty-five out of forty patients were started for reasons other than SH and 15 out of 40 had contraindications to CSII. Overall, CSII was associated with a reduction in HbA1c (9.6 +/- 2.7% to 8.3 +/- 1.2%, P = 0.011), SH (6.45 +/- 16.15/year to 0.34 +/- 1.01/year, P = 0.034) and DKA (1.83 +/- 4.48/year to 0.27 +/- 1.12/year, P = 0.036). The fall in SH was greater for patients started for SH (P < 0.001). However, only patients started for other indications showed a fall in HbA1c (P = 0.001). The fall in DKA rate was greater in patients with contraindications (P = 0.042), and they did not lose the other benefits of CSII therapy, including quality of life. In the setting of a specialist multidisciplinary service, CSII can be an effective and safe therapy. It confers benefit outside the setting of severe hypoglycaemia and can confer benefit in some patients with classic contraindications. This questions the validity of criteria that may exclude these patients in such a service.