Intravenous drug abuse and Type 1 diabetes: financial and healthcare implications.

AIMS: To determine the morbidity, mortality and healthcare costs of intravenous drug-abusing patients with Type 1 diabetes (IVDA-DM), who are admitted to hospital. METHODS: Retrospective case note analysis of admissions, complications and cost estimation over a 6-year period. Each drug-abusing patient (IVDA-DM) (n = 9) was compared with two controls (n = 18) with Type 1 diabetes but without a history of intravenous drug abuse (DM-controls). Admissions were also analysed for patients with intravenous drug abuse, but without Type 1 diabetes (IVDA-controls) (n = 198). Admissions were at a University teaching hospital in Liverpool, UK. DM-controls were drawn from a population attending diabetes outpatient clinics between 1997 and 2002 at the same hospital. The main outcome measures were: the duration and healthcare costs of hospital admissions per year, outpatient attendances per year, glycated haemoglobin (HbA(1c)), weight, micro- and macrovascular complications and mortality. RESULTS: Multiple admissions, mainly related to ketoacidosis, led to marked differences in mean (95% CI) inpatient days per year per patient [IVDA-DM 28.1 (13.6-42.7) vs. DM-control 1.1 (0.2-1.9); P < 0.0001], mean inpatient days per year per patient in critical care bed (IVDA-DM 1.7 (-0.7-4.2) vs. DM-control 0; P < 0.02) and mean costs of admission, per patient per year (pound sterling 7320 vs. pound sterling 230). The IVDA-DM group frequently omitted insulin, were underweight, failed to attend as outpatients and five had died by the end of 2002. The IVDA-controls spent considerably less time in hospital [3.4 (2.8-3.9) days per patient per year]. CONCLUSION: IVDA-DM patients have higher rates of diabetes complications, are admitted more frequently and have a high mortality compared with DM and IVDA-controls. The cost of inpatient care of this small group of patients was considerable.