Drug Reactions In Hospital Research Articles

Prevalence of Adverse Drug Reactions in Hospital Among Older Patients with and Without Dementia.

Older inpatients with dementia are at an increased risk of an adverse drug reaction (ADR) during hospitalization. To quantify the prevalence of ADRs in older inpatients according to dementia status and ADR definition approach and to identify risk factors of ADRs during hospitalization. This was a retrospective cohort study of 2000 inpatients aged ≥ 75 years admitted consecutively to six Sydney hospitals (1 July 2016 to 31 May 2017). Dementia was defined by diagnosis in electronic medical records. ADRs were defined according to two approaches: the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) and classification by a research pharmacist (subset cohort, n = 600). A binary logistic regression was conducted to determine risk factors of ADRs. Among 2000 patients, 25.9% (n = 517) were reported to have dementia. ADRs defined by ICD-10-AM were identified in 8.3% (n = 43) and 14.6% (n = 217) of inpatients with and without dementia respectively (p < 0.001). A total of 13.0% (n = 260) and 12.5% (n = 75) of patients had ADRs defined by ICD-10-AM and a research pharmacist, respectively. Key risk factors of ADRs were longer hospital stay [odds ratio (OR) 1.01, 95% confidence interval (CI) 1.01, 1.02) and a greater number of regular potentially inappropriate medicines (PIMs) on admission (OR 1.17, 95% CI 1.00, 1.38). ADRs were more prevalent among inpatients without dementia and when assessed by a research pharmacist. Our findings underline the need for improved ADR detection in older inpatients.

A holistic approach to adverse drug reactions in hospitals: Classification, risk factors, assessment and economic evaluation- A review

A holistic approach to adverse drug reactions in hospitals: Classification, risk factors, assessment and economic evaluation- A review

Time series analysis of using the PDCA method combined with the Teach-back method to improve spontaneous reports of adverse drug reactions in a grade IIIA hospital in China.

Spontaneous reporting of adverse drug reactions (ADRs) is essential for the post-marketing safety evaluation of drugs. Therefore, good monitoring of ADRs is vital for strengthening drug supervision, management, and guiding rational drug use. Chinese medical institutions are the primary source of ADR case reports, but the proportion of the reports in grade IIIA hospitals is still low due to serious under-reporting. The 3rd Affiliated Hospital of Chengdu Medical College, Chengdu Pidu District People's Hospital, also has such a problem. To improve the quantity and quality of ADR reports and enhance the level of pharmacovigilance in hospitals, the Third Affiliated Hospital of Chengdu Medical College, People's Hospital of Chengdu Pidu District experienced 10years to gradually establish a management model to improve the medical staff's reporting rate of spontaneous reporting of ADRs. The management model is led by clinical pharmacists and combines the PDCA with Teach-back methods. The purpose of this paper is to introduce the management model and discuss its advantages and shortcomings of this model. This study was conducted at the Third Affiliated Hospital of Chengdu Medical College-Chengdu Pidu District People's Hospital. From 2016, the daily management of reporting, auditing, and data improvement of adverse drug reactions in the hospital was carried out by clinical pharmacists, who used the PDCA method combined with the Teach-back method to continuously improve the reporting program of ADRs in the hospital during 2016-2021. Then, the proportion of spontaneous reports of total, new, and serious ADRs was compared before and after the intervention. Also, we performed a time series analysis using an autoregressive moving average model to assess changes in the total number of spontaneous ADR reports before the intervention (2013-2015), the first intervention (2016-2018), and the second intervention (2019-2021). After the combined PDCA and Teach-back method intervention, the median number of reported ADRs per year increased from 50 (range 37-55) in the pre-intervention period to 88 (range 83-162) in the first intervention period and to 374 in the second (range 312-566). Breakpoint regression analysis of the spontaneous reporting rate of ADRs showed that the instantaneous increase after the first intervention was not statistically significant (P = 0.526). However, the reporting rate of ADRs increased at a month-by-month growth rate during the second intervention compared to the first intervention. Its spontaneous reporting rate improved 1.034 times (P = 0.002). After the second intervention, the spontaneous reporting rate of ADRs transiently increased 6.111-fold (P < 0.001), and the month-to-month growth rate increased 1.024-fold (P < 0.001) again. The management model that combines the PDCA and the Teach-back method significantly improves the reporting rate of adverse drug reactions.

Adverse drug reactions in hospitals: population estimates for Portugal and the ICD-9-CM to ICD-10-CM crosswalk

BackgroundAdverse drug reactions (ADR), both preventable and non-preventable, are frequent and pose a significant burden. This study aimed to produce up-to-date estimates for ADR rates in hospitals, in Portugal, from 2010 to 2018. In addition, it explores possible pitfalls when crosswalking between ICD-9-CM and ICD-10-CM code sets for ADR identification.MethodsThe Portuguese Hospital Morbidity Database was used to identify hospital episodes (outpatient or inpatient) with at least one ICD code of ADR. Since the study period spanned from 2010 to 2018, both ICD-9-CM and ICD-10-CM codes based on previously published studies were used to define episodes. This was an exploratory study, and descriptive statistics were used to provide ADR rates and summarise episode features for the full period (2010–2018) as well as for the ICD-9-CM (2010–2016) and ICD -10-CM (2017–2018) eras.ResultsBetween 2010 and 2018, ADR occurred in 162,985 hospital episodes, corresponding to 1.00% of the total number of episodes during the same period. Higher rates were seen in the oldest age groups. In the same period, the mean annual rate of episodes related to ADR was 174.2/100,000 population. The episode rate (per 100,000 population) was generally higher in males, except in young adults (aged '15–20', '25–30' and '30–35' years), although the overall frequency of ADR in hospital episodes was higher in females.ConclusionsDespite the ICD-10-CM transition, administrative health data in Portugal remain a feasible source for producing up-to-date estimates on ADR in hospitals. There is a need for future research to identify target recipients for preventive interventions and improve medication safety practices in Portugal.

How to Use Quality Tools to Prevent Adverse Drug Reactions in Hospitals?

Adverse drug reactions (ADRs) and Drug-Drug interactions (DDIs) remain an important clinical problem in modern healthcare systems, particularly, with the rising complexity of therapeutics, ageing population and multi-morbidity. There is no doubt that the unpleasant impacts resulting from inaccurate or wrong dose which used in prophylaxis or treatment, will cause significant harm to the patient. Therefore, it is important to shed the light on these such cases in order to avoid further harm consequences. ADRs can be happened due to involvement of T-lymphocyte or IgE-mediated allergy. Hypersensitivity reactions have been highlighted in recent years, so, allergy test is a necessary step before taking medications that may cause hypersensitivity react ion. This article summarizes some of the key facts about ADRs and explores aspects related to their prevention, diagnosis, reporting and management in current clinical practice using strategies, procedures and tools for quality improvement to avoid any probable mistakes. The article will also illustrate the key role of healthcare practitioners in documenting and reporting the ADRs correctly.

An investigation of pharmacovigilance and reporting of adverse drug reactions in hospitals: a cross-sectional study in China

Background Pharmacovigilance is a science that plays a significant role in reducing ADRs and helps predict adverse reactions to drugs in community. To safely use drugs in treatment and prevention of disease, adverse drug reaction has been paid more attention. Objectives To evaluate the future needs of existing systems, the paper investigated the current state of pharmacovigilance and the reporting of ADR in Chinese hospitals. Methods This cross-sectional, questionnaire-based study involved 10,063 pharmacists, doctors, and nurses from primary, secondary, and tertiary hospitals in all 31 provinces of China. It was commissioned by the National Centre for ADR Monitoring of China and conducted in March 2020. Three areas were assessed: sociodemographic characteristics of participants, awareness of the pharmacovigilance system, and the current state of hospitals’ reporting of ADRs. Chi-square tests were used to calculate P values. Results Health care professionals had heard the term “pharmacovigilance” previously (89.40%) and knew the reporting object (68.47%), content (65.94%), and range (64.83%) of pharmacovigilance. Most hospitals dispatched responsible professionals (87.64%) and departments (86.25%) to monitor ADR reporting. A total of 58.66% of tertiary medical, 45.25% of secondary, and 38.90% of primary hospitals extracted ADRs from a hospital information system. Moreover, 53.09% of tertiary medical, 38.93% of secondary, and 23.89% of primary hospitals had established a prescription automatic screening system to warn about risks for ADRs. Health care professionals’ reports (99.92%) and patient feedback (77.99%) were included in most hospitals’ ADR reporting. Conclusions Chinese health care professionals generally have good awareness of pharmacovigilance, and pharmacovigilance is relatively more advanced in China compared to other developing countries.

Assessing Drug-Drug Interaction Potential among Patients Admitted to Surgery Departments in Three Palestinian Hospitals.

Background Drug-drug interactions (DDIs) are a common issue that leads to adverse drug reactions in hospitals. Patients in the surgical department are expected to have potential DDIs that may lead to morbidity and mortality. Objectives To study potential DDI prevalence in the surgery departments in 3 hospitals in Palestine. Moreover, to identify pertinent factors that are associated with drug-drug interactions. Method A cross-sectional study in 3 governmental Palestinian hospitals: Palestine Medical Complex, Rafidia Hospital, and Beit Jala Hospital. Patients who are 20 years old or above and admitted to the surgical wards between September 2017 and February 2018 were included in the study. Patient demographics, all medications given in the hospital, and hospitalization period were obtained from medical files. The digital clinical decision support system Micromedex® was used for analysis and classification of possible drug interactions. Bivariate analysis and logistic regression were used to study the risk factors for developing DDIs. Results 502 patients were included in this report. The prevalence of potential DDIs among patients admitted to surgery wards in three Palestinian hospitals was 56%. The number of detected potential DDIs per patient was 2.22 ± 3.76. The number of prescribed medications (P < 0.001) was found to increase the possibility of having drug interactions. Conclusions DDIs in Palestinian hospitals are a prevalent problem, and caution should be taken when ordering medications to hospitalized patients in surgery departments.

Prevalence of adverse drug events and adverse drug reactions in hospital among older patients with dementia: A systematic review.

This systematic review aimed to quantify the prevalence of adverse drug events (ADEs) and adverse drug reactions (ADRs) in older inpatients with dementia. A systematic search of observational studies was performed in Embase, Medline, PsycINFO, International Pharmaceutical Abstracts, Scopus and Informit. Articles published in English that reported the prevalence of ADEs or ADRs in hospital patients aged 65 years or older with dementia were included. Two authors reviewed titles and abstracts and all eligible full-text articles. Relevant information relating to ADEs, ADRs and dementia was obtained from each article. In total, 5 articles were included. One study reported the prevalence of ADEs to be 81.5%, defined using the Naranjo algorithm. Four studies assessed the prevalence of ADRs, ranging from 12.7 to 24.0%, assessed using various methods. One study defined ADRs according to the World Health Organization-Uppsala Monitoring Centre criteria, 2 studies employed the World Health Organization definition and 1 study did not explicitly define ADRs. The most frequently reported drug classes implicated in ADEs and ADRs were psychotropic, antihypertensive and analgesic drugs. Our findings suggest a high prevalence of ADEs and ADRs in older inpatients with dementia. However, only 1 study documented ADEs and there was variability in approaches to ADR assessment. A greater understanding of ADEs and ADRs, as well as tailored assessment tools, will promote prevention of ADEs and ADRs in people with dementia.

Preventability analysis of adverse drug reactions in a Jordanian hospital: a prospective observational study.

Background Adverse drug reactions remain to be an issue that compromisepatient's safety in Jordan and worldwide. In Jordan, an assessment of factors involved in preventability of adverse drug reactionshas not been conducted previously. Objectives To describe the proportion of preventable adverse drug reactions, and the causes of hospital-related preventableadverse reactions in one Jordanian hospital. Methods A prospective observational study of 4months duration conducted by clinical pharmacists in the hospital. Setting Surgical and medical wards in one Jordanian private hospital. Main outcome measure Proportions of admissions related to adverse drug reactions, proportions of preventablereactions and analysis of the factors involved in the preventableadverse drug reactions. Results Out of 350 admissions recorded during the study period, a total of 38 (10.8%) adverse reactionswere detected. Among those, 29 (8.3%) were detected in the hospital and 9 (2.6%) were the cause of the hospital admission. Many (44.7%) of the adverse drug reactions were preventable (31.6% were probably preventable and 13.1% were definitely preventable). About half (55.3%) were unpreventable. Insufficient monitoring was involved in 29.4% of the preventable adverse reactions and inappropriate dosing and drug-drug interactions were independently responsible for 17.6% of the preventableadverse reactions. Conclusion A high proportion of the identifiedadverse drug reactions were found to be preventable. Insufficient monitoring and inappropriate dosing were the most importantfactors associated with preventableadverse drug reactions. Nationally, more focused efforts need to be stimulated to prevent preventable adverse drug reactions in hospitals.

Drug-drug interaction study in an intensive care unit: An assessment of prevalence, nature, and severity of the medications involved

Background: Intensive care unit (ICU) patients are at an increased risk of drug-drug interactions (DDIs) due to polypharmacy and pharmacokinetic changes in critically ill patients. Adverse drug reactions in hospitals caused by DDIs pose a significant risk to the patient’s health outcome with an additional economic burden on the health -care system. Aims and Objectives: This study was conducted to measure the prevalence and nature of potential DDIs (pDDIs) as primary objective and to know the severity of pDDIs and association of pDDIs with the length of stay in ICU (if any) as a secondary objective. Materials and Methods: This was a 2-month, prospective, observational study that was conducted in an ICU of ESIC Medical College and Hospital, Gulbarga. Drugs.com interaction database was utilized to screen patient’s medication profiles for DDIs and for severity assessment. Results: Of 112 study population, 755 pDDIs were identified, averaging 6.74 interactions per patient. About 6.9% (52/755) were major, 75.9% (573/755) were moderate, and 19.9% (150/755) were minor DDIs. The most frequent drug pairs involved in pDDIs in major, moderate, and minor were rifampin and isoniazid (15.4%), furosemide and pantoprazole (4.01%), and digoxin and spironolactone (8%), respectively. Conclusions: DDIs occur frequently in the ICU. Nature and Severity of medications related to DDIs in an ICU differ from other hospital ICU settings. Based on the prescribing pattern in an ICU, a database at an institutional level can be developed so as to decrease the burden of interactions and overall result in improved patient safety.

Characterization of Serious Adverse Drug Reactions in Hospital to Determine Potential Implications of Mandatory Reporting

The Protecting Canadians from Unsafe Drugs Act will eventually require institutions to report all serious adverse drug reactions (ADRs), although the proposed regulations do not yet define what will need to be reported and by whom. Knowledge about the occurrence of serious ADRs in the hospital setting is needed to optimize the effectiveness of reporting and to determine the potential implications of mandatory reporting. To quantify and characterize suspected serious ADRs in patients admitted to a general medicine service, to assess the likelihood of causality, and to determine inter-rater agreement for identification of ADRs and assessment of their likelihood. This prospective observational study involved 60 consecutive patients admitted to a general medicine service at a tertiary care teaching centre starting on March 28, 2016. The primary outcome was the number of serious ADRs, defined by Health Canada as ADRs that result in hospital admission, congenital malformation, persistent or significant disability or incapacity, or death; that are life-threatening; or that require significant intervention to prevent one of these outcomes. Medical records were reviewed independently by pairs of pharmacists for serious ADRs, and the likelihood of causality was assessed using the World Health Organization-Uppsala Monitoring Centre system. Inter-rater agreement was calculated using the kappa score, and disagreements were resolved by discussion and consensus. Twenty-three serious ADRs occurred in the sample of 60 patients. The proportion of patients experiencing a serious ADR that contributed to the original hospital admission was 19/60 (32%, 95% confidence interval [CI] 20%-43%), and 4 patients (7%, 95% CI 0%-13%) experienced a serious ADR during their hospital stay. Inter-rater agreement for occurrence of serious ADRs was moderate (kappa 0.58, 95% CI 0.35-0.76). Reportable serious ADRs were common among patients admitted to a general medicine service. Canadian hospitals would face difficulties reporting all serious ADRs because of the frequency of their occurrence and the subjectivity of their identification.

Assessment of Adverse Drug Reactions Associated with Cardiovascular Agents and Antibiotics at a Tertiary Care Hospital

The assessment of Adverse Drug Reactions (ADRs) has become increasingly significant because of the introduction of a large number of potent toxic chemicals as drugs in the last two or three decades. Therefore, it is important that continuous monitoring of adverse drug reactions in hospitals could prevent serious consequences and unexpected effects of the drugs and improve the quality of treatment in patients. Antibiotics and cardiovascular agents are the most commonly prescribed drugs which are also involved with the highest number of adverse drug reactions in the hospitals. The objective of this study was to monitor and evaluate the adverse drug reactions caused by cardiovascular agents and antibiotics at a tertiary care hospital in Bangalore, for a period of 12 months between March “2017 to March 2018”. All in-patients of both genders who experienced an ADR during their hospital stay were enrolled for the study and exclusion criteria were patients admitted to hospital and did not experience an ADR. Out of 110 Adverse drug reactions, 57 (51.81%) were caused by cardiovascular agents and 53 (48.18%) were caused by antibiotics. Among the cardiovascular agents ADRs the most frequently reported ADRs were caused by furosemide 19 (33.33%) followed by telmisartan 5 (8.77%). Out of 53 (48.18%) ADRs caused by antibiotics, 8 (15.09%) were induced by ceftriaxone, followed by 7 (13.20%) piperacillin/tazobactam, 6 (11.32%) cefoperazone, 5 (9.43%) levofloxacin. The most common organ system affected was the gastrointestinal system with 31 (28.18%) followed by fluid and electrolytes 28 (25.45%), dermatological 21 (19.09%) and cardiovascular 7 (6.36%). The causality assessment of the ADRs was carried out using the Naranjo’s Scale algorithm and the majority of the ADRs were found to be possible 44 (40%). Antibiotics and cardiovascular agents are the most commonly prescribed medicines in hospitals, so it is important to notice the physicians with latest adverse drug reactions of these medications. This approach consequently reduces the chances of patient harm and also improves the patient's quality of treatment, reduces the cost burden and hospital stay and minimizes the antibiotics resistance due to unresponsiveness of medications in patients.

Adverse Drug Reactions in Hospital and Ambulatory Care Settings Identified Using a Large Administrative Database

Previous studies are limited in sample size and number of sites for the detection and characterization of adverse drug reactions (ADRs) in ambulatory care and hospital settings. To determine the prevalence and distribution of suspected ADRs according to demographic characteristics and drug classes for ambulatory care and hospitalized patients. A cross-sectional evaluation of administrative data from 2002-2005, containing a maximum of 20 million Medicare and commercially insured patients in a year, was completed. Individuals with one or more claims suggesting an ADR were identified, using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) criteria referred to as a "suspected ADR." Frequency of ICD-9-CM codes consistent with suspected ADRs for the 4 years was calculated for hospital and ambulatory care settings, based on age ranges, comorbidities, and drug classes. Between 2002 and 2005, the average annual prevalence of suspected ADRs was 0.5%, with a total of 249,633 suspected ADRs during the 4 years. The mean age of hospitalized patients experiencing a suspected ADR was 12 years older than that of ambulatory care patients and 20 years older than that of the general database population. Diseases of the circulatory and endocrine/nutritional/metabolic systems rank among the top 5 comorbid conditions in hospitalized patients who had a suspected ADR. Injury and poisoning was the primary comorbidity in ambulatory patients. High-risk medications frequently associated with suspected ADRs in both settings were antineoplastic and anticoagulant agents. Other drug classes commonly associated with suspected ADRs in hospitalized patients were antihypertensives and diuretics. For the ambulatory care setting, drug classes frequently associated with suspected ADRs were antirheumatic and antiarteriosclerotic agents. ADR detection, using administrative data, revealed differences in age, comorbidities, and drug classifications between ambulatory care and hospital settings. The results can be used to develop focused prevention strategies and targeted surveillance for individuals most at risk for developing ADRs.

Half of adverse drug reactions in hospital may be avoidable

Half of adverse drug reactions in hospital may be avoidable

Adverse Drug Reactions in Hospitals: A Narrative Review

The serious nature of adverse drug reactions (ADRs) has been highlighted in a number of instances over the last forty years, the most recent of these being the occurrence of serious thrombotic events with the use of COX-2 inhibitors. ADRs are estimated to be between the 4(th) and 6(th) leading cause of death in the USA, with fatal ADRs occurring in 0.32% of patients. A recent UK study showed that 6.5% of hospital admissions were related to ADRs. ADRs can therefore be regarded as a significant public health and economic problem. There is an urgent need to develop better preventive strategies to reduce the burden of ADRs. Because ADRs can affect any bodily system, can have many different clinical presentations, and are of widely variable severity, prevention will not be easy and will have to be multifactorial in its approach. This paper reviews the epidemiology of ADRs in hospitals and evaluates the research that has been undertaken to date to prevent ADRs.

Comprehensive surveillance of adverse drug reactions in hospital provides important data to inform the safe use of drug therapy

Comprehensive surveillance of adverse drug reactions in hospital provides important data to inform the safe use of drug therapy

Methods and systems to detect adverse drug reactions in hospitals.

Detection of adverse drug reactions (ADRs) in hospitals offers the chance to detect serious ADRs resulting in hospitalisation and ADRs occurring in hospitalised patients, i.e. patients with high comorbidity and receiving drugs that are administered only in hospitals. The most commonly applied methods involve stimulated spontaneous reporting of doctors and nurses, comprehensive collection by trained specialists and, more recently, computer-assisted approaches using routine data from hospital information systems. The different methods of ADR detection used result in different rates and types of ADRs and, consequently, in different drug classes being responsible for these ADRs. Another factor influencing the results of surveys is the interpretation of the term ADR, where some authors adhere to the strict definition of the World Health Organization and many others include intended and unintended poisoning as well as errors in prescribing and dispensing, thus referring to adverse drug events. Depending on the method used for screening of patients, a high number of possible ADRs and only few definite ADRs are found, or vice versa. These variations have to be taken into account when comparing the results of further analyses performed with these data. ADR rates and incidences in relation to the number of drugs prescribed or patients exposed have been calculated in only a few surveys and projects, and this interesting pharmacoepidemiological approach deserves further study. In addition, the pharmacoeconomic impact of ADRs, either resulting in hospitalisation or prolonging hospital stay, has been estimated using different approaches. However, a common standardised procedure for such calculations has not yet been defined. Although detection of ADRs in hospitals offers the opportunity to detect severe ADRs of newly approved drugs, these ADRs are still discovered by spontaneous reporting systems. The prospects offered by electronic hospital information systems as well as implementation of pharmacoepidemiological approaches increases the possibilities and the value of ADR detection in hospitals.

Incidence of Adverse Drug Reactions in Hospitalized Patients: A Meta-Analysis of Prospective Studies

Objective.—To estimate the incidence of serious and fatal adverse drug reactions (ADR) in hospital patients.Data Sources.—Four electronic databases were searched from 1966 to 1996.Study Selection.—Of 153, we selected 39 prospective studies from US hospitals.Data Extraction.—Data extracted independently by 2 investigators were analyzed by a random-effects model. To obtain the overall incidence of ADRs in hospitalized patients, we combined the incidence of ADRs occurring while in the hospital plus the incidence of ADRs causing admission to hospital. We excluded errors in drug administration, noncompliance, overdose, drug abuse, therapeutic failures, and possible ADRs. Serious ADRs were defined as those that required hospitalization, were permanently disabling, or resulted in death.Data Synthesis.—The overall incidence of serious ADRs was 6.7% (95% confidence interval [CI], 5.2%-8.2%) and of fatal ADRs was 0.32% (95% CI, 0.23%-0.41%) of hospitalized patients. We estimated that in 1994 overall 2216000 (1721000-2711000) hospitalized patients had serious ADRs and 106000 (76000-137000) had fatal ADRs, making these reactions between the fourth and sixth leading cause of death.Conclusions.—The incidence of serious and fatal ADRs in US hospitals was found to be extremely high. While our results must be viewed with circumspection because of heterogeneity among studies and small biases in the samples, these data nevertheless suggest that ADRs represent an important clinical issue.

Computerized surveillance of adverse drug reactions in hospital: implementation.

To implement and measure the effects of automatic computerized laboratory signals (ALS) as a detection support tool of adverse drug reactions (ADRs) in hospital. This was a prospective observational study of a total of 192 patients (199 sequential medical admissions) during a 2-month period in a 34-bed medical ward at the Hadassah University Hospital, Jerusalem, Israel. The study involved the routine (daily) distribution to staff physicians of lists of automatic signals generated from computerized laboratory data as potential indicators of ADRs. Patient charts were reviewed by the clinical pharmacology team for ADRs and to see whether these were recognized by the staff physicians. Seventy-one ADRs were detected in 64 of the 199 (32%) admissions. Twenty-seven per cent of the ADRs were serious, 9% of the admissions were due to ADRs. Two hundred and ninety-five ALS were generated involving 69% of the admissions. Sixty-one per cent of the ADRs were identified by ALS. ALS were present in 58% of the ADR negative admissions. Eighty-five per cent of the ADRs were recognized as such and 19% of the ALS-positive ADRs were not recognized by the staff physicians. The routine implementation of ALS doubled the number of ADRs recognized by the physicians while patients were hospitalized in the medical ward. The use of the system appeared valid, simple and potentially cost-effective.

Incidence of adverse drug reactions in hospitalized patients: a meta-analysis of prospective studies.

To estimate the incidence of serious and fatal adverse drug reactions (ADR) in hospital patients. Four electronic databases were searched from 1966 to 1996. Of 153, we selected 39 prospective studies from US hospitals. Data extracted independently by 2 investigators were analyzed by a random-effects model. To obtain the overall incidence of ADRs in hospitalized patients, we combined the incidence of ADRs occurring while in the hospital plus the incidence of ADRs causing admission to hospital. We excluded errors in drug administration, noncompliance, overdose, drug abuse, therapeutic failures, and possible ADRs. Serious ADRs were defined as those that required hospitalization, were permanently disabling, or resulted in death. The overall incidence of serious ADRs was 6.7% (95% confidence interval [CI], 5.2%-8.2%) and of fatal ADRs was 0.32% (95% CI, 0.23%-0.41%) of hospitalized patients. We estimated that in 1994 overall 2216000 (1721000-2711000) hospitalized patients had serious ADRs and 106000 (76000-137000) had fatal ADRs, making these reactions between the fourth and sixth leading cause of death. The incidence of serious and fatal ADRs in US hospitals was found to be extremely high. While our results must be viewed with circumspection because of heterogeneity among studies and small biases in the samples, these data nevertheless suggest that ADRs represent an important clinical issue.