Summary: | 博士 === 國立陽明大學 === 環境與職業衛生研究所 === 102 === 英文摘要
Abstract
Studies on adverse drug events (ADE) in Taiwan, especially ADEs leading to emergency department (ED) visit, remain scarce. We therefore conducted the following three studies: (1) epidemiological investigation of ADEs leading to ED visit; (2) the differences of clinical profiles of ADEs leading to ED visit between the older (≥ 65 years old) and younger (<65 years old) adults; (3) the risk factors for ADEs leading to ED visit among the older adults.
Part I: Epidemiological investigation of Patients Presenting with Adverse Drug Events in the Emergency Department
Background: Adverse drug events have been studied widely in hospitalised and emergency department patients. Less is known about the ED visits of drug-related injury in Taiwan. This study seeks to determine the incidence, risk and patient outcomes of ADE in an ED population.
Methods: We conducted a prospective observational cohort study of patients 18 years and older presenting to the ED of an urban, tertiary medical centre. ED visits between 1 March 2009 and 28 February 2010 identified by investigators for suspected ADE were further assessed by using the Naranjo Adverse Drug Reaction probability scale. Outcomes (ED disposition, injury severity and preventability) and associated variables (triage, gender, drug category, number of drugs, Charlson comorbidity index score and ADE mechanism) were measured.
Results: Of 58 569 ED visits, 452 patients (0.77%) had physician-documented ADE. 24% of patients with ADE were hospitalised with life-threatening conditions, with a mortality rate of 10.0%. The majority of ADE were considered preventable (73.4%), and the unintentional overdose was the most common cause. Cardiovascular agents accounted for the most ADE (25.8%) and consisted of 65.3% of ADE in patients aged 65 years and older. Risk factors for ADE-related hospitalisation were elderly age (odds ratio (OR) 1.9, 95% confidence interval (CI) 1.1–3.4), severity of ADE (OR 6.9, 95% CI 3.3–14.5) and higher Charlson comorbidity index scores (OR 3.4, 95% CI 2.0–5.7).
Conclusion: ADE-related ED visits are not uncommon in Taiwan and many cases are preventable. ED-based surveillance may provide useful information for monitoring outpatient ADE.
Part II: Different Characteristics of Adverse Drug Events between Older Adults and Younger Adults Presenting to a Taiwan Emergency Department
Study Objective: To compare the proportion, seriousness, preventability of adverse drug events (ADEs), and clinical profiles between the older adults (≥ 65 years old) and younger (<65 years old) adults presenting to the emergency department (ED).
Methods: We conducted a prospective observational cohort study of patients 18 years and older presenting to the ED. For all ED visits between March 1, 2009, and Feb 28, 2010, investigators identified ADEs and assessed cases using the Naranjo Adverse Drug Reaction probability scale. Outcomes (length of ED stay, hospitalization, seriousness, and preventability of ADE) and associated variables were measured and compared between younger and older adults.
Results: Of 58,569 ED visits, 295 older adults and 157 younger adults were diagnosed as having an ADE and included in our analysis. The proportion of ADEs leading to ED visits in the older group, 14.3 per 1000 (295/20,628), was significantly higher than younger group of 4.1 per 1000 (157/37,941).We found that older group with ADE had a longer ED stay and more preventable ADEs than younger group but there was no significant difference in serious ADEs (death and life-threatening) and hospitalization between the two groups. In the univariate analysis, older group were more likely to be male, have symptoms of fatigue or altered mental status, involve cardiovascular, renal, and respiratory systems, have higher Charlson comorbidity index scores, higher number of prescription medications, and higher proportion of unintentional overdose.
Conclusion: ADE-related ED visits in older adults are more common and preventable than those in younger adults.
Part III: Risk Factors Associated with Adverse Drug Events among Older Adults in Emergency Department
Background: Little is known about the emergency department (ED) visits from drug-related injury among older adults in Taiwan. This study seeks to identify risk factors associated with adverse drug events (ADEs) leading to ED visits.
Methods: We prospectively conducted a case-control study of patients 65 years and older presenting to the ED. ED visits between March 1, 2009 and Feb 28, 2010 identified by investigators for suspected ADEs were further assessed by using the Naranjo Adverse Drug Reaction probability scale. For each patient with an ADE, a control was selected and time-matched from the ED population of the study hospital. The association between the risk of adverse drug events and triage, age, gender, serum alanine transaminase (ALT), serum creatinine, number of medications, and Charlson Comorbidity Index scores were analyzed using logistic regression.
Results: Of 20,628 visits, 295 ADEs were physician-documented in older adults. Independent risk factors for ADEs included number of medications (adjusted odds ratio [OR] =4.1; 95% confidence interval [CI] 2.4 – 6.9 for 3-7 drugs; adjusted OR=6.4; 95% CI 3.7 -11.0 for 8 or more drugs) and increased concentration of serum creatinine (adjusted OR=1.5; 95% CI 1.1 – 2.2). Diuretics, analgesics, cardiovascular agents, anti-diabetic agents and anticoagulants were the medications most commonly associated with an ADE leading to ED visits.
Conclusions: This study suggests that prevention efforts should be focused on older patients with renal insufficiency and polypharmacy who are using high risk medications such as anticoagulants, diuretics, cardiovascular agents, analgesics, and anti-diabetic agents.
Adverse drug event (ADE) is an important medical issue that can result in high morbidity and medical expenditure, including ED visits, medication use, diagnostic test and hospital admission. Our study showed that ED plays an important role in screening and management of ADE. To improve patient safety, especially the use of prescription medications among older people, a national active surveillance program for outpatient ADE is pivotal in Taiwan.
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