National estimates of insulin-related hypoglycemia and errors leading to emergency department visits and hospitalizations.

IMPORTANCE: Detailed, nationally representative data describing high-risk populations and circumstances involved in insulin-related hypoglycemia and errors (IHEs) can inform approaches to individualizing glycemic targets. OBJECTIVE: To describe the US burden, rates, and characteristics of emergency department (ED) visits and emergency hospitalizations for IHEs. DESIGN, SETTING, AND PARTICIPANTS: Nationally representative public health surveillance of adverse drug events among insulin-treated patients seeking ED care (National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project) and a national household survey of insulin use (the National Health Interview Survey) were used to obtain data from January 1, 2007, through December 31, 2011. MAIN OUTCOMES AND MEASURES: Estimated annual numbers and estimated annual rates of ED visits and hospitalizations for IHEs among insulin-treated patients with diabetes mellitus. RESULTS: Based on 8100 National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance cases, an estimated 97,648 (95% CI, 64,410-130,887) ED visits for IHEs occurred annually; almost one-third (29.3%; 95% CI, 21.8%-36.8%) resulted in hospitalization. Severe neurologic sequelae were documented in an estimated 60.6% (95% CI, 51.3%-69.9%) of ED visits for IHEs, and blood glucose levels of 50 mg/dL (to convert to millimoles per liter, multiply by 0.0555) or less were recorded in more than half of cases (53.4%). Insulin-treated patients 80 years or older were more than twice as likely to visit the ED (rate ratio, 2.5; 95% CI, 1.5-4.3) and nearly 5 times as likely to be subsequently hospitalized (rate ratio, 4.9; 95% CI, 2.6-9.1) for IHEs than those 45 to 64 years. The most commonly identified IHE precipitants were reduced food intake and administration of the wrong insulin product. CONCLUSIONS AND RELEVANCE: Rates of ED visits and subsequent hospitalizations for IHEs were highest in patients 80 years or older; the risks of hypoglycemic sequelae in this age group should be considered in decisions to prescribe and intensify insulin. Meal-planning misadventures and insulin product mix-ups are important targets for hypoglycemia prevention efforts.

National surveillance of emergency department visits for outpatient adverse drug events in children and adolescents.

OBJECTIVE: To describe the national scope and magnitude of outpatient adverse drug events (ADEs) that lead to emergency department (ED) visits in children and adolescents. STUDY DESIGN: To conduct an active surveillance of patients 18 years of age or younger who came to EDs with ADEs from Jan 1, 2004, to Dec 31, 2005, through a nationally representative, stratified probability sample of 63 US hospitals with EDs. The main outcome measures were national estimates of the number, type, patient demographics, and clinical characteristics of ADEs. RESULTS: Annually, an estimated 158,520 patients

Evaluation and overview of the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance Project (NEISS-CADES).

BACKGROUND: Adverse drug events (ADEs) are an important cause of patient injury. Although most medications are prescribed and used in the outpatient setting, prevention efforts focus on the inpatient setting, partly because of limited data on outpatient events. We describe and evaluate a new system for surveillance of outpatient ADEs treated in hospital emergency departments (EDs). METHODS: We used guidelines for evaluating public health surveillance systems, developed by the Centers for Disease Control and Prevention, to assess the performance of the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project (NEISS-CADES) from January 1, 2004 through December 31, 2004. RESULTS: NEISS-CADES is a nationally representative surveillance system that identifies ADEs using ED clinical records. Of 10,383 reports in 2004, 100% listed patient age, sex, and disposition; 98% listed the implicated drugs. A 6-hospital evaluation of data quality, completeness, and other system attributes showed that NEISS-CADES data accurately reflected clinical records with respect to patient age and sex (100%), primary diagnosis (93%), implicated drugs (93%), primary treatments (80%), and diagnostic testing (61%). Sensitivity of case identification was estimated to be at least 0.33; estimated positive predictive value was 0.92. Data collection does not require additional work by clinical staff and has been well accepted by participating institutions. CONCLUSIONS: NEISS-CADES provides detailed and timely information on outpatient ADEs treated in EDs and identifies specific drugs and circumstances associated with these injuries. Findings from NEISS-CADES can help design and prioritize patient safety interventions for outpatient ADEs.

National surveillance of emergency department visits for outpatient adverse drug events.

CONTEXT: Adverse drug events are common and often preventable causes of medical injuries. However, timely, nationally representative information on outpatient adverse drug events is limited. OBJECTIVE: To describe the frequency and characteristics of adverse drug events that lead to emergency department visits in the United States. DESIGN, SETTING, AND PARTICIPANTS: Active surveillance from January 1, 2004, through December 31, 2005, through the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project. MAIN OUTCOME MEASURES: National estimates of the numbers, population rates, and severity (measured by hospitalization) of individuals with adverse drug events treated in emergency departments. RESULTS: Over the 2-year study period, 21,298 adverse drug event cases were reported, producing weighted annual estimates of 701,547 individuals (95% confidence interval [CI], 509,642-893,452) or 2.4 individuals per 1000 population (95% CI, 1.7-3.0) treated in emergency departments. Of these cases, 3487 individuals required hospitalization (annual estimate, 117,318 [16.7%]; 95% CI, 13.1%-20.3%). Adverse drug events accounted for 2.5% (95% CI, 2.0%-3.1%) of estimated emergency department visits for all unintentional injuries and 6.7% (95% CI, 4.7%-8.7%) of those leading to hospitalization and accounted for 0.6% of estimated emergency department visits for all causes. Individuals aged 65 years or older were more likely than younger individuals to sustain adverse drug events (annual estimate, 4.9 vs 2.0 per 1000; rate ratio [RR], 2.4; 95% CI, 1.8-3.0) and more likely to require hospitalization (annual estimate, 1.6 vs 0.23 per 1000; RR, 6.8; 95% CI, 4.3-9.2). Drugs for which regular outpatient monitoring is used to prevent acute toxicity accounted for 41.5% of estimated hospitalizations overall (1381 cases; 95% CI, 30.9%-52.1%) and 54.4% of estimated hospitalizations among individuals aged 65 years or older (829 cases; 95% CI, 45.0%-63.7%). CONCLUSIONS: Adverse drug events among outpatients that lead to emergency department visits are an important cause of morbidity in the United States, particularly among individuals aged 65 years or older. Ongoing, population-based surveillance can help monitor these events and target prevention strategies.

Emergency department visits for outpatient adverse drug events: demonstration for a national surveillance system.

STUDY OBJECTIVE: This project demonstrates the operational feasibility and epidemiologic usefulness of modifying a national injury surveillance system for active surveillance of outpatient adverse drug events treated in hospital emergency departments (EDs). METHODS: Coders were trained to identify and report physician-documented adverse drug events in 9 of 64 National Electronic Injury Surveillance System-All Injury Program hospital EDs (occurring July 17, 2002, to September 30, 2002). Feasibility was measured by timeliness and completeness of adverse drug event reporting. Outcomes (ED discharge disposition and injury type) and associated variables (age, sex, drug category, and adverse drug event mechanism) were measured. RESULTS: There were 598 patients with physician-documented adverse drug events (7 per 1,000 visits). Nearly 70% of adverse drug event cases were reported within 7 days of the ED visit; key data elements (drug name, disposition from ED, and event description) were completed for more than 98% of cases. Nine percent of patients with adverse drug events were hospitalized, and unintentional overdoses was the most common mechanism of adverse drug events (39%). Patients with unintentional overdoses were more likely to be hospitalized than those with adverse drug reactions (adjusted odds ratio [OR] 5.9, 95% confidence interval [CI] 2.2 to 16; adverse-effects referent; allergic reactions, adjusted OR 0.7, 95% CI 0.2 to 2.4). Warfarin and insulins were associated with 16% of adverse drug events overall and 33% of adverse drug events in patients aged 50 years or older. CONCLUSION: Active surveillance for outpatient adverse drug events using the National Electronic Injury Surveillance System-All Injury Program is feasible. Ongoing, population-based ED surveillance can help characterize the burden of outpatient adverse drug events, prioritize areas for further research and intervention, and monitor progress on adverse drug event prevention.