Are analogue insulins better than soluble in continuous subcutaneous insulin infusion? Results of a meta-analysis

Aims The properties of rapid-acting insulin analogues are thought to be particularly appropriate for use in continuous subcutaneous insulin infusion (CSII) or insulin pump therapy. We conducted a systematic review and meta-analysis of trials comparing rapid-acting insulin analogues with soluble insulin in CSII. Methods The following databases were searched ( last search June 2002): MEDLINE 1985 - 2002; Embase 1980 - 2002; PubMed internet version, records added June 2001 to June 2002; Science Citation Index 1990 - 2002; BIOSIS 1999 - 2002; Web of Science Proceedings 1990 - 2002; and the Cochrane Library, including DARE and the HTA databases. Randomized controlled trials and crossover studies with at least 10 weeks on each treatment were included. Data extraction and quality assessment were undertaken by one reviewer and checked by a second. A meta-analysis was undertaken using a random effects model. Results A significant improvement of 0.26% (95% confidence interval - 0.47, - 0.06%) in glycated haemoglobin was demonstrated with lispro. Some studies reported fewer hypoglycaemic episodes with analogue insulin but this varied according to the definitions used. No differences in insulin dosage or weight were seen. Two studies reported patient preference, with analogues preferred in both. The extra cost per annum ranges from pound72 ( at 40 units per day) to pound150 ( at 84 units per day). Conclusions Insulin analogues result in a modest but significant reduction in HbA(1c) compared with soluble insulin when used in CSII, and are preferred by patients.