In-hospital mortality in a tertiary referral hospital: causes of death and comparison between patients with and without diabetes

Abstract

Introduction: Subjects with type 2 diabetes mellitus (T2DM) have increased morbidity and mortality mainly due to macrovascular complications. In addition, diabetic patients show increased in-hospital admissions in comparison with nondiabetic patients. However, in-hospital mortality data for patients with T2DM are not available in our country. The aim of the present study was to examine mortality rates in diabetic compared to nondiabetic patients admitted to a tertiary hospital during a 10-year period (1998-2007).

Material and methods: We performed a retrospective analysis of mortality rates in patients with and without T2DM hospitalised in a tertiary care hospital during the years 1998-2007. Demographic characteristics, medical history and outcome were collected from the patients' medical records. Patients with type 1 diabetes were excluded from the analysis.

Results: A total of 16 125 patients' records were studied (14 005 without diabetes and 2 120 with T2DM). In the total sample, 1 467 (9.1%) deaths were recorded. Mortality rates were higher in the diabetic than in the nondiabetic patients (11.2% versus 8.7%, respectively, p<0.001). Age of death did not differ between diabetic and nondiabetic patients (age+/-SD: 77.1+/-9.5 vs. 77.6+/-16.3 years, p=0.73). Median length of hospital stay was higher in the diabetic than in the nondiabetic patients (p=0.03). Mortality was higher in the diabetic in comparison with the nondiabetic females (59.9% vs. 52.7%, respectively, p=0.04), while no gender difference was found in males. Cerebrovascular disease was the commonest cause of death in both diabetic and nondiabetic patients (41.6% vs. 30.3%, p=0.001), followed by infections (23.1% vs. 21.7%, respectively, p=0.62). Death rates from malignancies were more common in the nondiabetic in comparison with the diabetic patients (18.8% vs. 4.2%, p<0.001). No significant differences were observed between the two study groups regarding mortality caused by cardiovascular events and chronic renal failure.

Conclusion: The present study showed that diabetic patients and especially females had increased in-hospital mortality compared with nondiabetic patients. Cerebrovascular disease and infections were the more common cause of death in both groups.