RESUMEN
We aimed to evaluate the frequency of hypoglycemia and its impact on the length of stay and all-cause in-hospital mortality in hospitalized patients with diabetes. We used data from the Basic Minimum Data Set of the Spanish National Health System. Hypoglycemia was defined as having an ICD-9-CM code 250.8, 251.0, 251.1, and 251.2, and categorized as primary if it was the main cause of admission and secondary if it occurred during the hospital stay. The association between hypoglycemia and the study outcomes was evaluated in two cohorts - with and without secondary hypoglycemia - matched by propensity scores and using multivariate models. Among the 5,447,725 discharges with a diagnosis of diabetes recorded from January 1997 to December 2010, there were 92,591 (1.7%) discharges with primary hypoglycemia and 154,510 (2.8%) with secondary hypoglycemia. The prevalence of secondary hypoglycemia increased from 1.1% in 1997 to a peak of 3.8% in 2007, while the prevalence of primary hypoglycemia remained fairly stable. Primary hypoglycemia was associated with reduced in-hospital mortality (Odds ratio [OR] 0.06; 95% Confidence interval [CI], 0.03-0.10) and a significant decrease in time to discharge (Hazard ratio [HR] 2.53; 95% CI, 2.30-2.76), while secondary hypoglycemia was associated with an increased likelihood of in-hospital mortality (OR 1.12; 95% CI, 1.09-1.15) and a significant increase in time to discharge (HR 0.80; 95% CI, 0.79-0.80). In conclusion, the prevalence of secondary hypoglycemia is increasing in patients with diabetes and is associated with an increased likelihood of in-hospital mortality and a longer hospital stay.