A call to action for adverse drug event (ADE) detection and prevention

Injury from medication use, known as an adverse drug event (ADE) accounts for millions of emergency department visits globally and thousands of hospitalizations annually within the United States. Efforts to prevent and detect ADEs within healthcare systems are complicated by data quality, lack of data standardization, and actionable clinical decision support systems. United States Pharmacopeia (USP) proposes the use of an ADE value set, a standardized grouping of medical terms, to improve the identification, documentation, and use of ADE information in EHRs. Artificial Intelligence and Machine Learning capabilities would be further strengthened through the standardization of ADE data and information.

The problem with the existing reporting standards for adverse event and medical error research

The Enhancing the Quality and Transparency of Health Research (EQUATOR) Network indexes over 600 reporting guidelines designed to improve the reproducibility of manuscripts across medical fields and study designs. Although several such reporting guidelines touch on adverse events that may occur in the context of a study, there is a large body of research whose primary focus is on adverse events, near-misses and medical errors that do not currently have a dedicated reporting guideline to help set reporting standards and facilitate comparisons across studies. As part of the process prescribed by EQUATOR for developing such a reporting guideline, we performed a needs assessment, evaluating whether existing standards address key features of a proposed reporting guideline in development, entitled Standard Elements in Studies of Adverse Events and Medical Error (SESAME). We evaluated 12 EQUATOR reporting guidelines for the presence of eight key features of SESAME. Five of the 12 failed to include any of these key features. None of the remaining seven incorporated more than four of the eight SESAME key components, confirming the need for a dedicated reporting guideline for studies of adverse events and medical errors.

Incidence of drug-related adverse events related to the use of high-alert drugs: A systematic review of randomized controlled trials

Background

High-alert medication (HAM) is more predictable to cause significant harm to the patient, even when used as intended. The damage related to the HAM lead not only suffering to the patient, but also raise the additional costs associated with care.

Objective

Evaluate the incidence of drug-related adverse events related to the use of high-alert medications.

Methods

It was conducted an active search for information through COCHRANE databases, LILACS, SciELO, SCOPUS, PubMed/MEDLINE and WEB OF SCIENCE. The search strategy included the following terms: "Patient safety", "Medication errors" and "Hospital" and "High Alert Medications" or "Dangerous Drugs" in different combinations. Then two reviewers independently conducted a preliminary evaluation of relevant titles, abstracts and finally full-text. Studies quality was evaluated according to PRISMA declaration.

Results

The systematic review evaluated seven articles, which showed that only 11 HAM identified in the literature could have serious events. The most frequently cited were warfarin (22.2%) which progressed from deep vein thrombosis to gangrene, suggesting lower initial doses, followed by cyclophosphamide (22.2%) and cyclosporine (22.2%) which presented invasive fungal infection and death. In addition to these, morphine was compared with its active metabolite (M6G), with M6G causing fewer serious clinical events related to nausea and vomiting, reducing the need for concomitant use of antiemetics.

Conclusions

The most reported drug classes in the articles included that were related to incidence of drug-related adverse events in use of high-alert medications: morphine, M6G-glucuronide, haloperidol, promethazine, ivabradine, digoxin, warfarin, ximelagatran, cyclophosphamide, cyclosporine, and ATG. The formulate protocols for the use of these medications, with importance placed on evaluating, among the classes, the medication that causes the least harm.

Preventability of Adverse Drug Reactions Related to Antibiotics: An Assessment Based on Spontaneous Reporting System

BACKGROUND

Antibiotics are commonly used in both outpatient and inpatient settings and are responsible for the majority of adverse drug reaction (ADR) reports. We aimed to characterize spontaneously reported ADRs associated with antibiotics and assessing the preventability of these ADRs in a Vietnamese setting.

MATERIALS AND METHODS

We conducted a retrospective descriptive study based on ADRs related to antibiotics spontaneously reported by healthcare workers to the National Pharmacovigilance Database of Vietnam (NPDV) between June 2018 and May 2019. The characteristics of included reports were descriptively analyzed. The preventability of reported ADRs was assessed using a standardized preventability scale. We identified the leading causes and described the characteristics associated with preventable ADRs (pADRs).

RESULTS

We included 6385 antibiotic-related reports from a total of 12,056 reports submitted to the NPDV during the study period. Beta-lactam antibiotics, mostly broad-spectrum with parenteral route, were suspected in the majority cases. The most commonly reported pADRs were allergic reactions, mostly classified under skin and subcutaneous tissue disorders. Of all included cases, 537 cases (8.4%) were deemed as associated with pADRs. Major causes of pADRs include potentially inappropriate prescribing (352/537, 65.5%) and re-administration of antibiotics causing prior allergy/allergies (99/537, 18.4%). The majority of pADRs involved the use of beta-lactam antibiotics with inappropriate indications.

CONCLUSION

ADRs related to antibiotic use represent more than half of ADRs spontaneously reported in Vietnam. Approximately one in every ten reported cases is associated with pADRs. The majority pADRs can be prevented through simple improvement in antibiotic prescribing practices.

Medication-related Medical Emergency Team activations: a case review study of frequency and preventability

OBJECTIVES

Despite recognition of clinical deterioration and medication-related harm as patient safety risks, the frequency of medication-related Rapid Response System activations is undefined. We aimed to estimate the incidence and preventability of medication-related Medical Emergency Team (MET) activations and describe the associated adverse medication events.

METHODS

A case review study of consecutive MET activations at two acute, academic teaching hospitals in Melbourne, Australia with mature Rapid Response Systems was conducted. All MET activations during a 3-week study period were assessed for a medication cause including identification of the contributing adverse medication event and its preventability, using validated tools and recognised classification systems.

RESULTS

There were 9439 admissions and 628 MET activations during the study period. Of these, 146 (23.2%) MET activations were medication related: an incidence of 15.5 medication-related MET activation per 1000 admissions. Medication-related MET activations occurred a median of 46.6 hours earlier (IQR 22-165) in an admission than non-medication-related activations (p=0.001). Furthermore, this group also had more repeat MET activations during their admission (p=0.021, OR=1.68, 95% CI 1.09 to 2.59). A total of 92 of 146 (63%) medication-related MET activations were potentially preventable. Tachycardia due to omission of beta-blocking agents (10.9%, n=10 of 92) and hypotension due to cumulative toxicity (9.8%, n=9 of 92) or inappropriate use (10.9%, n=10 of 92) of antihypertensives were the most common adverse medication events leading to potentially preventable medication-related MET activations.

CONCLUSIONS

Medications contributed to almost a quarter of MET activations, often early in a patient's admission. One in seven MET activations were due to potentially preventable adverse medication events. The most common of these were omission of beta-blockers and clinically inappropriate antihypertensive use. Strategies to prevent these events would increase patient safety and reduce burden on the MET.

Incidence, severity, and preventability of adverse events during the induction of patients with acute lymphoblastic leukemia in a tertiary care pediatric hospital in Mexico

Healthcare-associated adverse events represent a heavy burden of symptoms for pediatric oncology patients. Their description allows knowing the safety and quality of the care processes in countries with limited resources. This study aimed to describe the incidence, types, severity, and preventability of adverse events occurring in pediatric patients with acute lymphoblastic leukemia during the induction phase in a tertiary care pediatric hospital in Mexico. This study analyzed a cohort based on medical records of between 2015 and 2017. Initially, information on patients and adverse events was collected; subsequently, two pediatric oncologist reviewers independently classified adverse events, severity and preventability. Agreement between reviewers was evaluated. Adverse events incidence rates were estimated by type, severity, and preventability. One-hundred and eighty-one pediatric patients pediatric patients with acute lymphoblastic leukemia were studied. An overall adverse events rate of 51.8 per 1000 patient-days was estimated, involving 81.2% of patients during induction. Most adverse events were severe or higher (52.6%). Infectious processes were the most common severe or higher adverse event (30.5%). The presence of adverse events caused 80.2% of hospital readmissions. Of the adverse events, 10.5% were considered preventable and 53.6% could be ameliorable in severity. Improving the safety and quality of the care processes of children with acute lymphoblastic leukemia is possible, and this should contribute to the mitigation and prevention of adverse events associated morbidity and mortality during the remission induction phase.

Inter-rater reliability of assessments regarding the quality of drug treatment, and drug-related hospital admissions

AIMS

To investigate inter-rater agreement on the quality of drug treatment, and the relationship between the drug treatment and hospital admission.

METHODS

Three specialist physicians and two resident physicians determined, independently and in consensus, the quality of drug treatment from an overall medical perspective, and its association with admission, in 30 randomly selected patients (50% female, median age 72 years) admitted to Sahlgrenska University Hospital, Sweden, in April 2018. The inter-rater agreement was evaluated with Gwet's agreement coefficient (AC₁ ).

RESULTS

In all, 200 (95%) out of 210 drugs at admission and 238 (97%) out of 245 drugs at discharge were assessed as reasonable drug treatment by all assessors. Conversely, none of the drugs at admission, and two at discharge, were assessed as unreasonable drug treatment by all assessors (AC₁ : 0.88 and 0.94 [all], 0.86 and 0.95 [specialists], 0.92 and 0.92 [residents], respectively). The assessments regarding the association between the drug treatment and the hospital admission (not related or main/contributory reason) were consistent between the assessors for 16 out of 30 patients (AC₁ : 0.67 [all], 0.74 [specialists], 0.54 [residents]). In none of the three cases where the hospital admission was considered possibly attributable to a prescribing error did the assessors make consistent assessments.

CONCLUSIONS

As the inter-rater agreement ranged between weak and almost perfect, the reliability of assessments of drug treatment quality, as well as adverse consequences, appears to be a methodological concern. To yield acceptably reliable results regarding both drug treatment aspects at issue, specialist physicians should be involved.

Preventable adverse drug events causing hospitalisation: identifying root causes and developing a surveillance and learning system at an urban community hospital, a cross-sectional observational study

OBJECTIVES

To identify root causes of preventable adverse drug events (pADEs) contributing to hospital admission; to develop key messages which identify actions patients/families and healthcare providers can take to prevent common pADEs found; to develop a surveillance learning system for the community.

METHODS

Cross-sectional observational study; 120 patients and families, 61 associated healthcare providers were interviewed then root cause analysis was performed to develop key learning messages and an electronic reporting tool was designed. Most common pADE-related medical conditions and their root causes and most common pADE root causes of entire cohort are reported.

RESULTS

Most common pADE-related medical conditions: chronic obstructive pulmonary disease/asthma (13.3%), bleeding (12.5%), hypotension (12%), heart failure (10%), acute kidney injury (5%) and pneumonia (5%). Most common root causes were: providers not confirming that the patient/family understands information given (29.2%), can identify how a medication helps them/have their concerns addressed (16.7%), can identify if a medication is working (14.1%) or causing a side effect (23.3%); can enact medication changes (7.5%); absence of a sick day management plan (12.5%), and other action plans to help patients respond to changes in their clinical status (10.8%); providers not assessing medication use and monitoring competency (19.2%). Ten key learning messages were developed and a pADE surveillance learning system was implemented.

CONCLUSIONS

To prevent pADEs, providers need to confirm that patients/families understand information given, how a medication helps them, how to recognise and respond to side effects, how to enact medication changes and follow action plans; providers should assess patient's/families' medication use and monitoring competency.

Effect of a patient-centred deprescribing procedure in older multimorbid patients in Swiss primary care - A cluster-randomised clinical trial

Background

Management of patients with polypharmacy is challenging, and evidence for beneficial effects of deprescribing interventions is mixed. This study aimed to investigate whether a patient-centred deprescribing intervention of PCPs results in a reduction of polypharmacy, without increasing the number of adverse disease events and reducing the quality of life, among their older multimorbid patients.

Methods

This is a cluster-randomised clinical study among 46 primary care physicians (PCPs) with a 12 months follow-up. We randomised PCPs into an intervention and a control group. They recruited 128 and 206 patients if ≥60 years and taking ≥five drugs for ≥6 months. The intervention consisted of a 2-h training of PCPs, encouraging the use of a validated deprescribing-algorithm including shared-decision-making, in comparison to usual care. The primary outcome was the mean difference in the number of drugs per patient (dpp) between baseline and after 12 months. Additional outcomes focused on patient safety and quality of life (QoL) measures.

Results

Three hundred thirty-four patients, mean [SD] age of 76.2 [8.5] years participated. The mean difference in the number of dpp between baseline and after 12 months was 0.379 in the intervention group (8.02 and 7.64; p = 0.059) and 0.374 in the control group (8.05 and 7.68; p = 0.065). The between-group comparison showed no significant difference at all time points, except for immediately after the intervention (p = 0.002). There were no significant differences concerning patient safety nor QoL measures.

Conclusion

Our straight-forward and patient-centred deprescribing procedure is effective immediately after the intervention, but not after 6 and 12 months. Further research needs to determine the optimal interval of repeated deprescribing interventions for a sustainable effect on polypharmacy at mid- and long-term. Integrating SDM in the deprescribing process is a key factor for success.

Trial registration

Current Controlled Trials, prospectively registered ISRCTN16560559 Date assigned 31/10/2014.

The Prevention of Polypharmacy in Primary Care Patients Trial (4P-RCT).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-020-01870-8.

An investigation into the avoidability of adverse drug reactions using the LAAT and modified Hallas tools

An adverse drug reactions avoidability tool called the Liverpool ADR avoidability assessment tool (LAAT) was recently developed (for research purposes), and subsequently validated with mixed interrater reliability (IRR). We investigated the comparative IRR of this tool in an inpatient cohort to ascertain its practical application in this setting.The patient population was comprised of 44 ADR drug pairs drawn from an observational prospective cohort of patents with ADR attending a Weill Cornell Medicine-affiliated tertiary medical Centre in Doha Qatar (Hamad General Hospital). Using the LAAT, and modified Hallas tools, 4 independent raters (2 Clinical Pharmacologists, and 2 General Physicians) assessed and scored the 44 ADR-drug pairs. Agreement proportions between the rating pairs were evaluated as well individual/overall kappa statistics and intraclass correlation coefficients. We evaluated the weight of each of the 7 questions on the LAAT tool to ascertain its determinative role.Across 44 ADR-drug pairs, the overall median Fleiss kappa using the LAAT, and modified Hallas tools were 0.67 (interquartile range (IQR) 0.55, 0.76), 0.36 (IQR, 0.23-0.71) respectively. The overall percentage pairwise agreement with the LAAT and modified Hallas tools were 78.5%, and 62.2% respectively. Exact pairwise agreement occurred in 37 out of 44 (range 0.71-1), and 27 of 44 (0.53-0.77) ADR-drug pairs using the LAAT and modified Hallas tools respectively. Using the LAAT tool, the overall intraclass correlation coefficient was 0.68 (CI 0.55, 0.79), and 0.37 (CI 0.22, 0.53) with the modified Hallas tool.We report a higher proportion of "possible" and "definite" avoidability outcomes of adverse drug reactions compared with the modified Hallas, or that reported by developers of the LAAT tool. Although initially developed for research purposes, our report has suggested for the first time a potential applicability of this tool in clinical environment as well.

Reducing avoidable medication-related harm: What will it take?

Consumption of quality-assured medicines is expected to maintain or improve population health. Yet in a number of situations, what is realized is lower health benefits or magnified safety risks. Recognizing the public health implications of safety risks or medication-related harm, and that some types of harm are avoidable, the World Health Organization has initiated the third Global Patient Safety challenge on Medication Safety. Under the term "Medication Without Harm", this Challenge aims to assess the scope and nature of avoidable medication-related harm, create a framework for intervention and develop national guidance and tools to support safer medication use. The global target under the Challenge is to reduce the level of severe avoidable medication-related harm by 50% over a five-year period or within the next five years. Given a higher morbidity and mortality due to medication-related harm in low-income countries, this paper evaluates what needs to be done in low-income countries in order to achieve the global target. The ideal solution advocated requires that health planners in each low-income country determine what fraction of safety risks or harm can be prevented; and the relationship between number or frequency of avoidable harm or safety risks and the resource costs of treatment or prevention. In the absence of such information, this paper discusses a number of prevention strategies that might help; arguing that the period over which avoidable medication-related harm can be reduced by 50% will depend on whether significant continuous investments in health-system strengthening are made prior to and within that period.

Methods for evaluating adverse drug event preventability in emergency department patients

BACKGROUND

There is a high degree of variability in assessing the preventability of adverse drug events, limiting the ability to compare rates of preventable adverse drug events across different studies. We compared three methods for determining preventability of adverse drug events in emergency department patients and explored their strengths and weaknesses.

METHODS

This mixed-methods study enrolled emergency department patients diagnosed with at least one adverse drug event from three prior prospective studies. A clinical pharmacist and physician reviewed the medical and research records of all patients, and independently rated each event's preventability using a "best practice-based" approach, an "error-based" approach, and an "algorithm-based" approach. Raters discussed discordant ratings until reaching consensus. We assessed the inter-rater agreement between clinicians using the same assessment method, and between different assessment methods using Cohen's kappa with 95% confidence intervals (95% CI). Qualitative researchers observed discussions, took field notes, and reviewed free text comments made by clinicians in a "comment" box in the data collection form. We developed a coding structure and iteratively analyzed qualitative data for emerging themes regarding the application of each preventability assessment method using NVivo.

RESULTS

Among 1356 adverse drug events, a best practice-based approach rated 64.1% (95% CI: 61.5-66.6%) of events as preventable, an error-based approach rated 64.3% (95% CI: 61.8-66.9%) of events as preventable, and an algorithm-based approach rated 68.8% (95% CI: 66.1-71.1%) of events as preventable. When applying the same method, the inter-rater agreement between clinicians was 0.53 (95% CI: 0.48-0.59), 0.55 (95%CI: 0.50-0.60) and 0.55 (95% CI: 0.49-0.55) for the best practice-, error-, and algorithm-based approaches, respectively. The inter-rater agreement between different assessment methods using consensus ratings for each ranged between 0.88 (95% CI 0.85-0.91) and 0.99 (95% CI 0.98-1.00). Compared to a best practice-based assessment, clinicians believed the algorithm-based assessment was too rigid. It did not account for the complexities of and variations in clinical practice, and frequently was too definitive when assigning preventability ratings.

CONCLUSION

There was good agreement between all three methods of determining the preventability of adverse drug events. However, clinicians found the algorithmic approach constraining, and preferred a best practice-based assessment method.

Incidence, causes, and consequences of preventable adverse drug reactions occurring in inpatients: A systematic review of systematic reviews

BACKGROUND

Preventable adverse drug reactions (PADRs) in inpatients are associated with harm, including increased length of stay and potential loss of life, and result in elevated costs of care. We conducted an overview of reviews (i.e., a systematic review of systematic reviews) to determine the incidence of PADRs experienced by inpatients. Secondary review objectives were related to assessment of the effects of patient age, setting, and clinical specialty on PADR incidence.

METHODS

The protocol was registered in PROSPERO (CRD42016043220). We performed a search of Medline, Embase, and the Cochrane Library, limiting languages of publication to English and French. We included published systematic reviews that reported quantitative data on the incidence of PADRs in patients receiving acute or ambulatory care in a hospital setting. The full texts of all primary studies for which PADR data were reported in the included reviews were obtained and data relevant to review objectives were extracted. Quality of the included reviews was assessed using the AMSTAR-2 tool. Both narrative summaries of findings and meta-analyses of primary study data were undertaken.

RESULTS

Thirteen systematic reviews encompassing 37 unique primary studies were included. Across primary studies, the PADR incidence was highly varied, ranging from 0.006 to 13.3 PADRs per 100 patients, with a pooled incidence estimate of 0.59 PADRs per 100 patients. Substantial heterogeneity was present across both reviews and primary studies with respect to review/study objectives, patient age, hospital setting, medical discipline, definitions and assessment tools used, event detection methods, endpoints of interest, and units of measure. Thirteen primary studies used prospective event detection methods and had a pooled PADR incidence of 3.13 (2.87-3.38) PADRs per 100 patients; however, extreme statistical heterogeneity (I2 = 97%) indicated this finding should be considered with caution. Subgroup meta-analyses demonstrated that PADR incidence varied significantly with event detection method (prospective > retrospective > voluntary reporting methods), hospital setting (ICU > wards), and medical discipline (medical > surgical). High statistical heterogeneity (I2 > 80%) was present across all analyses, indicating results should be interpreted with caution. Effects of patient age could not be assessed due to poor reporting of age groups used in primary studies.

DISCUSSION

The method of event detection appeared to significantly influence PADR incidence, with prospective methods having the highest reported PADR rate. This finding is in agreement with the background literature. High methodological and statistical heterogeneity across primary studies evaluating adverse drug events reduces the validity of the overall PADR incidence derived from the meta-analyses of the pooled data. Data pooled from studies using only prospective methods of event detection should provide an overall estimate closest to the true PADR incidence; however, our estimate should be considered with caution due to the statistical heterogeneity found in this group of studies. Future studies should employ prospective methods of detection. This review demonstrates that the true overall incidence of PADRs is likely much greater than the overall pooled incidence estimate of 0.59 PADRs per 100 patients obtained when event detection method was not taken into consideration.

Development of a 'ready-to-use' tool that includes preventability, for the assessment of adverse drug events in oncology

Background Adverse drug events (ADEs) occur frequently in oncology and justify continuous assessment and monitoring. There are several methods for detecting them, but the trigger tool method seems the most appropriate. Although a generic tool exists, its use for ADEs in oncology has not been convincing. The development of a focused version is therefore necessary. Objective To provide an oncology-focused trigger tool that evaluates the prevalence, harm, and preventability in a standardised method for pragmatic use in ADE surveillance. Setting Hospitals with cancer care in France. Method The tool has been constructed in two steps: (1) constitution of an oncology-centred list of ADEs; 30 pharmacists/practitioners in cancer care from nine hospitals selected a list of ADEs using a method of agreement adapted from the RAND/UCLA Appropriateness Method; and (2) construction of three standardised dimensions for the characterisation of each ADE (including causality, severity, and preventability). Main outcome measure The main outcome measure was validation of the tool, including preventability criteria. Results The tool is composed of a final list of 15 ADEs. For each ADE, a 'reviewer form' has been designed and validated by the panel. It comprises (1) the trigger(s), (2) flowcharts to guide the reviewer, (3) criteria for grading harm, and (4) a standardised assessment of preventability with 6-14 closed sentences for each ADE in terms of therapeutic management and/or prevention of side-effects. Conclusion A complete 'ready-to-use' tool for ADE monitoring in oncology has been developed that allows the assessment of three standardised dimensions.

Preventable ADRs leading to hospitalization - results of a long-term prospective safety study with 6,427 ADR cases focusing on elderly patients

BACKGROUND

Studies evaluating the impact of age and potentially inappropriate medication (PIM) on avoidable adverse drug reactions (ADRs) are scarce.

METHODS

In this prospective, multi-center, long-term (8.5 years) observational study, we analysed ADRs leading to hospitalization in departments of internal medicine. ADRs causality and preventability were assessed using standardised algorithms. PIM was defined based on the PRISCUS-list. Multivariate analyses and estimation of ADR incidence rates were conducted.

RESULTS

Of all 6,427 ADR patients, a preventable ADR was present in 1,253 (19.5%) patients (elderly patients ≥70 years: 828). Risk factors for preventable ADRs in elderly patients were multimorbidity, two to four ADR-causative drugs, and intake of particular compounds (e.g. spironolactone) but not sex, PIM usage, or the total number of drugs. Regarding particular compounds associated with preventable ADRs, highest incidence rates for preventable ADRs were found for patients aged ≥70 years for spironolactone (3.3 per 1,000 exposed persons (95% CI: 1.4-6.6)) and intermediate-acting insulin (3.3 per 1,000 exposed persons (95% CI: 1.6-6.1)).

CONCLUSION

Avoiding PIM usage seems to be of limited value in increasing safety in elderly patients whereas our results underline the importance of an individualized medication review of the most commonly implicated drugs in preventable ADRs (supported by BfArM FoNr: V-11337/68605/2008-2010).

Adverse Drug Events and Medication Errors in African Hospitals: A Systematic Review

Background

Medication errors and adverse drug events are universal problems contributing to patient harm but the magnitude of these problems in Africa remains unclear.

Objective

The objective of this study was to systematically investigate the literature on the extent of medication errors and adverse drug events, and the factors contributing to medication errors in African hospitals.

Methods

We searched PubMed, MEDLINE, EMBASE, Web of Science and Global Health databases from inception to 31 August, 2017 and hand searched the reference lists of included studies. Original research studies of any design published in English that investigated adverse drug events and/or medication errors in any patient population in the hospital setting in Africa were included. Descriptive statistics including median and interquartile range were presented.

Results

Fifty-one studies were included; of these, 33 focused on medication errors, 15 on adverse drug events, and three studies focused on medication errors and adverse drug events. These studies were conducted in nine (of the 54) African countries. In any patient population, the median (interquartile range) percentage of patients reported to have experienced any suspected adverse drug event at hospital admission was 8.4% (4.5–20.1%), while adverse drug events causing admission were reported in 2.8% (0.7–6.4%) of patients but it was reported that a median of 43.5% (20.0–47.0%) of the adverse drug events were deemed preventable. Similarly, the median mortality rate attributed to adverse drug events was reported to be 0.1% (interquartile range 0.0–0.3%). The most commonly reported types of medication errors were prescribing errors, occurring in a median of 57.4% (interquartile range 22.8–72.8%) of all prescriptions and a median of 15.5% (interquartile range 7.5–50.6%) of the prescriptions evaluated had dosing problems. Major contributing factors for medication errors reported in these studies were individual practitioner factors (e.g. fatigue and inadequate knowledge/training) and environmental factors, such as workplace distraction and high workload.

Conclusion

Medication errors in the African healthcare setting are relatively common, and the impact of adverse drug events is substantial but many are preventable. This review supports the design and implementation of preventative strategies targeting the most likely contributing factors.

Electronic supplementary material

The online version of this article (10.1007/s40801-017-0125-6) contains supplementary material, which is available to authorized users.

A literature-based economic evaluation of healthcare preventable adverse events in Europe

Purpose

To establish from the literature, cost of preventable adverse events (PAEs) to member states of the Joint Action European Union Network for Patient Safety and Quality of Care.

Data sources

We searched MEDLINE, EMBASE and CINAHL for studies in Europe estimating cost of adverse events (AEs) and PAEs (2000-March 2016). Using data from the literature, we estimated PAE costs based on national 2013 total health expenditure (THE) data reported by World Health Organization and converted to 2015 Euros.

Study selection/Data extraction

Information on type, frequency and incremental cost per episode or estimated cost of AEs was extracted. Total annual disability-adjusted life years (DALYs) resulting from PAEs in 30 EU nations were calculated using an estimate from a published study and adjusted for the percentage of AEs considered preventable.

Result of data synthesis

Published estimates of costs of AEs and PAEs vary based on the care setting, methodology, population and year conducted. Only one study was from primary care, the majority were conducted in acute care. Nine studies estimated percentage of THE caused by AEs, 13 studies calculated attributable length of stay. We estimated the annual cost of PAEs to the 30 nations in 2015 to be in the range of 17-38 billion Euros, total DALYs lost from AEs as 3.5 million, of which 1.5 million DALYs were likely due to PAEs.

Conclusion

The economic burden of AEs and PAEs is substantial. However, whether patient safety interventions will be 'cost saving' depends on the effectiveness and costs of the interventions.

Hospitalizations due to preventable adverse reactions-a systematic review

PURPOSE

The study aimed to measure the percentage of preventable adverse drug reactions that lead to the hospitalization (PADRAd) and to explore the heterogeneity in its estimation through subgroup analysis of study characteristics.

METHODS

Two investigators independently searched in electronic databases and related bibliography for prospective studies involving PADRAd. We excluded studies investigating medication errors and spontaneous and retrospective reporting. The primary outcome was PADRAd percentage. To explore the heterogeneity, we performed subgroup analysis based on study region, wards, age groups, adverse drug reaction (ADR) definitions, preventability assessment, ADR identification methods, study duration and sample size. We explored fatal PADRAd and causative drugs as a secondary outcome. We used the generic inverse variance method with random effect model to compute meta-analytic summary.

RESULTS

Of the 68 full-text articles assessed, we included 22 studies. The mean PADRAd percentage was 45.11 % (95 % CI = 33.06-57.15; I 2 = 99 %). Studies including elderly (63.31 %) and all age groups (49.03 %) showed higher percentages than paediatric population (16.40 %). Studies examining all hospital populations showed higher percentages than specific wards. We observed high percentages in studies using Edwards and Aronson as an ADR definition and Hallas et al. as a preventability assessment tool. After age group adjustment, ADR detection methods did not show significant difference. The fatal PADRAd percentage was 1.58 % (95 % CI = -0.60 to 3.76; I 2 = 47 %). Paediatric and elderly studies showed a different causative drug pattern.

CONCLUSION

Variation in PADRAd across the studies can be explained by difference in study populations and data collection methods. Extrapolation of preventable reactions should be carried out considering all these factors with caution.

Development of the Liverpool Adverse Drug Reaction Avoidability Assessment Tool

Aim

To develop and test a new tool to assess the avoidability of adverse drug reactions that is suitable for use in paediatrics but which is also applicable to a variety of other settings.

Methods

The study involved multiple phases. Preliminary work involved using the Hallas scale and a modification of the existing Hallas scale, to assess two different sets of adverse drug reaction (ADR) case reports. Phase 1 defined, modified and refined a new tool using multidisciplinary teams. Phase 2 involved the assessment of 50 ADR case reports from a prospective study of paediatric inpatients by individual assessors. Phase 3 compared assessments with the new tool for individuals and groups in comparison to the ‘gold standard’ (the avoidability outcome set by a panel of senior investigators: an experienced clinical pharmacologist, paediatrician and pharmacist).

Main Outcome Measures

Inter-rater reliability (IRR), measure of disagreement and utilization of avoidability categories.

Results

Preliminary work—Pilot phase: results for the original Hallas cases were fair and pairwise kappa scores ranged from 0.21 to 0.36. Results for the modified Hallas cases were poor, pairwise kappa scores ranged from 0.06 to 0.16.

Phase 1: on initial use of the new tool, agreement between the two multidisciplinary groups was found on 13/20 cases with a kappa score of 0.29 (95% CI -0.04 to 0.62).

Phase 2: the assessment of 50 ADR case reports by six individual reviewers yielded pairwise kappa scores ranging from poor to good 0.12 to 0.75 and percentage exact agreement (%EA) ranged from 52–90%.

Phase 3: Percentage exact agreement ranged from 35–70%. Overall, individuals had better agreement with the ‘gold standard’.

Conclusion

Avoidability assessment is feasible but needs careful attention to methods. The Liverpool ADR avoidability assessment tool showed mixed IRR. We have developed and validated a method for assessing the avoidability of ADRs that is transparent, more objective than previous methods and that can be used by individuals or groups.

Adaptation and validation of an adverse drug reaction preventability score for bleeding due to vitamin K antagonists

Although drug therapy is inherently associated with the risk of adverse drug reactions (ADRs), some of these events are preventable. The estimated proportion of preventable ADRs varies from one study or clinical context to another. Bleeding caused by antithrombotic agents (and particularly vitamin K antagonists, VKAs) constitutes one of the most frequent causes of ADR-related hospitalization.Hence, the objective of the present study was to adapt and validate an ADR preventability score for bleeding due to VKAs and evaluate the preventability of bleeding in 906 consecutive hospitalized, VKA-treated adult patients with a risk of major bleeding (defined as an international normalized ratio ≥5) over a 2-year period. A specific preventability scale for VKA-associated bleeding was developed by adapting a published tool.Overall, 241 of the 906 patients in the study experienced at least 1 VKA-associated bleeding event. The scale's reliability was tested by 2 different evaluators. The inter-rater reliability (evaluated by calculation of Cohen's kappa) ranged from "good" to "excellent." Lastly, the validated scale was used to assess the preventability of the VKA-associated bleeding. We estimated that bleeding was preventable or potentially preventable in 109 of the 241 affected patients (45.2%).We have developed a useful, reliable tool for evaluating the preventability of VKA-associated bleeding. Application of the scale in a prospective study revealed that a high proportion of VKA-associated bleeding events in hospitalized, at-risk adult patients were preventable or potentially preventable.

Preventability of Voluntarily Reported or Trigger Tool-Identified Medication Errors in a Pediatric Institution by Information Technology: A Retrospective Cohort Study

INTRODUCTION

Information technology (IT) has the potential to prevent medication errors. While many studies have analyzed specific IT technologies and preventable adverse drug events, no studies have identified risk factors for errors still occurring that are not preventable by IT.

OBJECTIVES

The objective of this study was to categorize reported or trigger tool-identified errors and adverse events (AEs) at a pediatric tertiary care institution. Also, we sought to identify medication errors preventable by IT, determine why IT-preventable errors occurred, and to identify risk factors for errors that were not preventable by IT.

METHODS

This was a retrospective analysis of voluntarily reported or trigger tool-identified errors and AEs occurring from 1 July 2011 to 30 June 2012. Medication errors reaching the patients were categorized based on the origin, severity, and location of the error, the month in which they occurred, and the age of the patient involved. Error characteristics were included in a multivariable logistic regression model to determine independent risk factors for errors occurring that were not preventable by IT. A medication error was defined as a medication-related failure of a planned action to be completed as intended or the use of a wrong plan to achieve an aim. An IT-preventable error was defined as having an IT system in place to aid in prevention of the error at the phase and location of its origin.

RESULTS

There were 936 medication errors (identified by voluntarily reporting or a trigger tool system) included and analyzed. Drug administration errors were identified most frequently (53.4% ), but prescribing errors most frequently caused harm (47.2 % of harmful errors). There were 470 (50.2 %) errors that were IT preventable at their origin, including 155 due to IT system bypasses, 103 due to insensitivity of IT alerting systems, and 47 with IT alert overrides. Dispensing, administration, and documentation errors had higher odds than prescribing errors for being not preventable by IT [odds ratio (OR) 8.0, 95 % CI 4.4-14.6; OR 2.4, 95 % CI 1.7-3.7; and OR 6.7, 95 % CI 3.3-14.5, respectively; all p < 0.001). Errors occurring in the operating room and in the outpatient setting had higher odds than intensive care units for being not preventable by IT (OR 10.4, 95 % CI 4.0-27.2, and OR 2.6, 95 % CI 1.3-5.0, respectively; all p ≤ 0.004).

CONCLUSIONS

Despite extensive IT implementation at the studied institution, approximately one-half of the medication errors identified by voluntarily reporting or a trigger tool system were not preventable by the utilized IT systems. Inappropriate use of IT systems was a common cause of errors. The identified risk factors represent areas where IT safety features were lacking.

Assessment of a new instrument for detecting preventable adverse drug reactions

BACKGROUND

Pharmacovigilance centres (PVCs) in the World Health Organization (WHO) Programme for International Drug Monitoring have demonstrated their ability to detect preventable adverse drug reactions (ADRs) in their databases. In this field, there is no gold-standard method for detecting medication errors and evaluating ADR preventability. Therefore, we developed, from existing tools, a preventability assessment method: the 'P Method' (PM).

OBJECTIVE

To present the PM and to evaluate its inter-rater reliability.

METHODS

The PM includes 20 explicit criteria for assessing ADR preventability. This approach is based on identification of any potentially preventable risk factor that increases the likelihood of ADR occurrence. The outcome of the preventability assessment results in one of three possible scores: 'preventable', 'non-preventable' or 'not assessable'. The PM was tested in a multicentre study involving nine national PVCs. Two experienced reviewers at each participating PVC independently analysed the preventability of 183 ADRs, applying the PM.

RESULTS

The overall agreement between all reviewers for assessment of ADR preventability was 'fair', with a kappa value of 0.27 [95 % confidence interval (CI) 0.21-0.40]. The level of agreement between reviewer pairs ranged from 'slight', with a kappa value of 0.12 (95 % CI -0.03 to 0.27), to 'substantial', with a kappa value of 0.69 (95 % CI 0.48-0.89).

CONCLUSION

The analysis of the agreements and disagreements between reviewers highlighted where improvements might be made. Given that no standard assessment tool exists in the WHO Programme, the transparency of the assessment process in this method provides a substantial basis for further development and for support in signalling possible preventability.

Detection of Patients at High Risk of Medication Errors: Development and Validation of an Algorithm

Medication errors (MEs) are preventable and can result in patient harm and increased expenses in the healthcare system in terms of hospitalization, prolonged hospitalizations and even death. We aimed to develop a screening tool to detect acutely admitted patients at low or high risk of MEs comprised by items found by literature search and the use of theoretical weighting. Predictive variables used for the development of the risk score were found by the literature search. Three retrospective patient populations and one prospective pilot population were used for modelling. The final risk score was evaluated for precision by the use of sensitivity, specificity and area under the ROC (receiver operating characteristic) curves. The variables used in the final risk score were reduced renal function, the total number of drugs and the risk of individual drugs to cause harm and drug-drug interactions. We found a risk score in the prospective population with an area under the ROC curve of 0.76. The final risk score was found to be quite robust as it showed an area under the ROC curve of 0.87 in a recent patient population, 0.74 in a population of internal medicine and 0.66 in an orthopaedic population. We developed a simple and robust score, MERIS, with the ability to detect patients and divide them according to low and high risk of MEs in a general population admitted at acute admissions unit. The accuracy of the risk score was at least as good as other models reported using multiple regression analysis.

Pharmacoepidemiology at Nordic School of Public Health NHV: Examples from 1999 to 2014

BACKGROUND

Pharmacoepidemiology is a branch of public health and had a place at the Nordic School of Public Health. Courses, Master's theses and Doctorates of Public Health (DrPH) in Pharmacoepidemiology were a relatively minor, but still important part of the school's activities.

METHODS

This paper gives a short background, followed by some snapshots of the activities at NHV, and then some illustrative case-studies. These case-studies list their own responsible co-authors and have separate reference lists.

RESULTS

In the Nordic context, NHV was a unique provider of training and research in pharmacoepidemiology, with single courses to complete DrPH training, as well as implementation of externally-funded research projects.

CONCLUSIONS

With the closure of NHV at the end of 2014, it is unclear if such a comprehensive approach towards pharmacoepidemiology will be found elsewhere in the Nordic countries.

[Developing a terminology in the French language for clinical practice and research in drug safety]

While several attempts have been made to clarify the English terminology of drug-related iatrogeny, a consensus has still not been reached in the French language. We set up a multidisciplinary task force to propose a terminology that differs from the one used in pharmacovigilance and risk management. We prefer the term "adverse drug event" (ADE) over "adverse drug reaction", and recommend avoiding the term "adverse event", which is too general. We propose to classify ADEs as "direct drug effect" or "drug involvement in a multifactorial pathological condition", taking into account the close relationship commonly found between drug and non-drug etiologies of a pathology. The consistent association between the notions "error" and "preventability" is also questionable, and we suggest assessing the "ameliorability" of ADEs rather than their "preventability". "Misuse" (i.e., the non-respect by the patient of the drug label) must be distinguished from "off-label use or substance abuse".

A systematic review of adult admissions to ICUs related to adverse drug events

Adverse drug events (ADE) may lead to hospital admission, and in some cases admission to an ICU is mandatory. We conducted a systematic review dealing with the incidence of ADE requiring ICU admission in adult patients, the reference population being all ICU admissions. Medline, Embase and Web of Science databases were screened from January 1982 to July 2014, using appropriate key words. Only original articles in English reporting the incidence of ADE requiring ICU admission in adult patients among total ICU admissions were included. Article eligibility was assessed by two independent reviewers, a third being involved in cases of disagreement. All reported characteristics (type of ICU, characteristics of patients, incidence of ADE, severity and preventability, drugs involved, causality) in the selected articles were collected for the review. The quality of studies was independently assessed by two reviewers with a specific score that we developed. A meta-analysis was conducted. Inclusion criteria were fulfilled by 11 studies out of the 4,311 identified in the initial literature search. The median (interquartile) quality score was 0.61 (0.44; 0.69). The reported incidences of ADE requiring ICU admission in adult patients ranged from 0.37 to 27.4%, with an associated mortality rate ranging from 2 to 28.1% and a mean length of stay ranging from 2.3 to 6.4 days. Preventable events accounted for 17.5 to 85.7% of the events. Costs and mechanisms at the root of ADE were investigated in only two and five studies, respectively. The forest plot examining the incidence of ADE requiring ICU admission in adult patients was associated with high heterogeneity (I² statistic >98%), and the shape of the corresponding funnel plot was asymmetric. Heterogeneity across studies concerned many features, including studied populations, events considered, causality assessment methods, definitions of preventability and severity. Despite the heterogeneity of the reports, our review indicates that ICU admission due to ADE is a significant issue that should deserve further interest. The review led us to propose a list of items devoted to the reporting of future studies on ADE requiring ICU admissions.

Prevalence, nature and potential preventability of adverse drug events - a population-based medical record study of 4970 adults

AIMS

To estimate the 3 month prevalence of adverse drug events (ADEs), categories of ADEs and preventable ADEs, and the preventability of ADEs among adults in Sweden. Further, to identify drug classes and organ systems associated with ADEs and estimate their seriousness.

METHODS

A random sample of 5025 adults in a Swedish county council in 2008 was drawn from the Total Population Register. All their medical records in 29 inpatient care departments in three hospitals, 110 specialized outpatient clinics and 51 primary care units were reviewed retrospectively in a stepwise manner, and complemented with register data on dispensed drugs. ADEs, including adverse drug reactions (ADRs), sub-therapeutic effects of drug therapy (STEs), drug dependence and abuse, drug intoxications from overdose, and morbidities due to drug-related untreated indication, were detected during a 3 month study period, and assessed for preventability.

RESULTS

Among 4970 included individuals, the prevalence of ADEs was 12.0% (95% confidence interval (CI) 11.1, 12.9%), and preventable ADEs 5.6% (95% CI 5.0, 6.2%). ADRs (6.9%; 95% CI 6.2, 7.6%) and STEs (6.4%; 95% CI 5.8, 7.1%) were more prevalent than the other ADEs. Of the ADEs, 38.8% (95% CI 35.8-41.9%) was preventable, varying by ADE category and seriousness. ADEs were frequently associated with nervous system and cardiovascular drugs, but the associated drugs and affected organs varied by ADE category.

CONCLUSIONS

The considerable burden of ADEs and preventable ADEs from commonly used drugs across care settings warrants large-scale efforts to redesign safer, higher quality healthcare systems. The heterogeneous nature of the ADE categories should be considered in research and clinical practice for preventing, detecting and mitigating ADEs.

ADRIC: Adverse Drug Reactions In Children – a programme of research using mixed methods

Aims

To comprehensively investigate the incidence, nature and risk factors of adverse drug reactions (ADRs) in a hospital-based population of children, with rigorous assessment of causality, severity and avoidability, and to assess the consequent impact on children and families. We aimed to improve the assessment of ADRs by development of new tools to assess causality and avoidability, and to minimise the impact on families by developing better strategies for communication.

Review methods

Two prospective observational studies, each over 1 year, were conducted to assess ADRs in children associated with admission to hospital, and those occurring in children who were in hospital for longer than 48 hours. We conducted a comprehensive systematic review of ADRs in children. We used the findings from these studies to develop and validate tools to assess causality and avoidability of ADRs, and conducted interviews with parents and children who had experienced ADRs, using these findings to develop a leaflet for parents to inform a communication strategy about ADRs.

Results

The estimated incidence of ADRs detected in children on admission to hospital was 2.9% [95% confidence interval (CI) 2.5% to 3.3%]. Of the reactions, 22.1% (95% CI 17% to 28%) were either definitely or possibly avoidable. Prescriptions originating in the community accounted for 44 out of 249 (17.7%) of ADRs, the remainder originating from hospital. A total of 120 out of 249 (48.2%) reactions resulted from treatment for malignancies. Off-label and/or unlicensed (OLUL) medicines were more likely to be implicated in an ADR than authorised medicines [relative risk (RR) 1.67, 95% CI 1.38 to 2.02;p < 0.001]. When medicines used for the treatment of oncology patients were excluded, OLUL medicines were not more likely to be implicated in an ADR than authorised medicines (RR 1.03, 95% CI 0.72 to 1.48;p = 0.830). For children who had been in hospital for > 48 hours, the overall incidence of definite and probable ADRs based on all admissions was 15.9% (95% CI 15.0 to 16.8). Opiate analgesic drugs and drugs used in general anaesthesia (GA) accounted for > 50% of all drugs implicated in ADRs. The odds ratio of an OLUL drug being implicated in an ADR compared with an authorised drug was 2.25 (95% CI 1.95 to 2.59;p < 0.001). Risk factors identified were exposure to a GA, age, oncology treatment and number of medicines. The systematic review estimated that the incidence rates for ADRs causing hospital admission ranged from 0.4% to 10.3% of all children [pooled estimate of 2.9% (95% CI 2.6% to 3.1%)] and from 0.6% to 16.8% of all children exposed to a drug during hospital stay. New tools to assess causality and avoidability of ADRs have been developed and validated. Many parents described being dissatisfied with clinician communication about ADRs, whereas parents of children with cancer emphasised confidence in clinician management of ADRs and the way clinicians communicated about medicines. The accounts of children and young people largely reflected parents’ accounts. Clinicians described using all of the features of communication that parents wanted to see, but made active decisions about when and what to communicate to families about suspected ADRs, which meant that communication may not always match families’ needs and expectations. We developed a leaflet to assist clinicians in communicating ADRs to parents.

Conclusion

The Adverse Drug Reactions In Children (ADRIC) programme has provided the most comprehensive assessment, to date, of the size and nature of ADRs in children presenting to, and cared for in, hospital, and the outputs that have resulted will improve the management and understanding of ADRs in children and adults within the NHS. Recommendations for future research: assess the values that parents and children place on the use of different medicines and the risks that they will find acceptable within these contexts; focusing on high-risk drugs identified in ADRIC, determine the optimum drug dose for children through the development of a gold standard practice for the extrapolation of adult drug doses, alongside targeted pharmacokinetic/pharmacodynamic studies; assess the research and clinical applications of the Liverpool Causality Assessment Tool and the Liverpool Avoidability Assessment Tool; evaluate, in more detail, morbidities associated with anaesthesia and surgery in children, including follow-up in the community and in the home setting and an assessment of the most appropriate treatment regimens to prevent pain, vomiting and other postoperative complications; further evaluate strategies for communication with families, children and young people about ADRs; and quantify ADRs in other settings, for example critical care and neonatology.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Occurrence and preventability of adverse drug events in surgical patients: a systematic review of literature

BACKGROUND

Adverse drug events (ADEs) are a considerable cause of inhospital morbidity and mortality. Patient flow differs substantially for surgical and nonsurgical patients: surgical patients are subjected to multiple medication changes related to surgical intervention or postoperative care. The objective of this study is to systematically review the occurrence and nature of ADEs in surgical patients. Also, a comparison with nonsurgical patients was made.

METHODS

A search was conducted in Embase and Medline identifying studies that reported observational data on the occurrence and nature of ADEs in surgical hospitalised adult patients. If sufficient data were available, the occurrence of (preventable) ADEs was compared between surgical and nonsurgical patients.

RESULTS

Six studies fulfilled the inclusion criteria. The occurrence of ADEs in surgical patients ranged from 2.0 to 27.7 per 100 admissions, from 4.7 to 8.9 per 1,000 patient days, or involved 8.9% of the patients. Proportions of preventable ADEs in surgical patients were 18% and 54%, described in two studies. A head-to-head comparison of surgical patients and nonsurgical patients was possible for five of six studies. The occurrence of ADEs in nonsurgical patients was significantly higher than in surgical patients in three studies.

CONCLUSIONS

ADEs are a relevant problem in surgical patients and nonsurgical patients, with a high proportion of preventable ADEs. The occurrence of ADEs appears to be higher in nonsurgical patients than in surgical patients. However, studies lack details on the differences in nature of ADEs between hospital populations. To improve medication safety this knowledge is essential.

Prevalence and perceived preventability of self-reported adverse drug events--a population-based survey of 7099 adults

Purpose

Adverse drug events (ADEs) are common and often preventable among inpatients, but self-reported ADEs have not been investigated in a representative sample of the general public. The objectives of this study were to estimate the 1-month prevalence of self-reported ADEs among the adult general public, and the perceived preventability of 2 ADE categories: adverse drug reactions (ADRs) and sub-therapeutic effects (STEs).

Methods

In this cross-sectional study, a postal survey was sent in October 2010 to a random sample of 13 931 Swedish residents aged ≥18 years. Self-reported ADEs experienced during the past month included ADRs, STEs, drug dependence, drug intoxications and morbidity due to drug-related untreated indication. ADEs could be associated with prescription, non-prescription or herbal drugs. The respondents estimated whether ADRs and STEs could have been prevented. ADE prevalences in age groups (18–44, 45–64, or ≥65 years) were compared.

Results

Of 7099 respondents (response rate 51.0%), ADEs were reported by 19.4% (95% confidence interval, 18.5–20.3%), and the prevalence did not differ by age group (p>0.05). The prevalences of self-reported ADRs, STEs, and morbidities due to drug-related untreated indications were 7.8% (7.2–8.4%), 7.6% (7.0–8.2%) and 8.1% (7.5–8.7%), respectively. The prevalence of self-reported drug dependence was 2.2% (1.9–2.6%), and drug intoxications 0.2% (0.1–0.3%). The respondents considered 19.2% (14.8–23.6%) of ADRs and STEs preventable. Although reported drugs varied between ADE categories, most ADEs were attributable to commonly dispensed drugs. Drugs reported for all and preventable events were similar.

Conclusions

One-fifth of the adult general public across age groups reported ADEs during the past month, indicating a need for prevention strategies beyond hospitalised patients. For this, the underlying causes of ADEs should increasingly be investigated. The high burden of ADEs and preventable ADEs from widely used drugs across care settings supports redesigning a safer healthcare system to adequately tackle the problem.

Inter-rater reliability of the assessment of adverse drug reactions in the hospitalised elderly

BACKGROUND

The identification and assessment of adverse drug reactions (ADRs) is very challenging especially among the older person. Inter observer reliability of an ADR classification system by different healthcare providers is vital to establish the validity of the reaction.

OBJECTIVE

To assess the inter-rater reliability of an ADR classification system in hospitalised elderly patients and to investigate the differences in reliability by different professions.

METHODS

From a cohort of 330 elderly patients, patients who experienced a suspected medication related incident (n=87) were selected. The data were analysed by four healthcare professionals (2 pharmacists and 2 physicians) who independently classified the events into event type, types of adverse drug reactions, severity and preventability after a standardised induction based on previously published criteria. Fleiss' kappa was used to assess the level of agreement between the four raters. The difference in level of agreement between the professions was assessed using the weighted least-squares approach for comparing correlated kappa of Barnhart et al.

RESULTS

Pharmacists and physicians showed high agreement in the identification and on the type and causality of ADRs. However there was lower (moderate) agreement for the severity (kappa = 0.61) and preventability of ADR (kappa = 0.48). Statistically significant differences were also noted between the professions; pharmacists have higher agreement in the classification of preventability (p=0.03) whereas the physicians pairs showed stronger agreement for classifying severity (p<0.001).

CONCLUSION

Despite the high agreement in the identification, type and causality of ADRs, physicians and pharmacists have difficulties in classifying preventability and severity in a reliable way. A multi-disciplinary approach would enable each profession to share their expert knowledge in order to facilitate better or safer patient care.

Recognition of adverse drug events in older hospitalized medical patients

Objective

To assess medical teams’ ability to recognize adverse drug events (ADEs) in older inpatients.

Methods

The study cohort comprised 250 patients aged 65 years or older consecutively admitted to Internal Medicine wards of three hospitals in the Netherlands between April and November 2007. An independent expert team identified ADEs present upon admission or occurring during hospitalization by a structured retrospective patient chart review. For all ADEs identified, the expert team assessed causality, severity, preventability, and recognition by medical teams.

Results

The medical teams did not recognize 19.9 % of all ADEs present upon admission {60.4 ADEs [95 % confidence interval (CI) 51.5–70.8] per 100 hospitalizations} and 20.3 % of all ADEs occurring during the hospital stay [47.2 ADEs (95 % CI 39.4–56.5) per 100 hospitalizations]. Unrecognized ADEs were significantly more often ADEs with possible causality (p=0.014, df=1), ADEs caused by medication errors (p<0.001, df=1), and ADEs not manifesting as new symptoms (p<0.001, df=1). The medical teams did not recognize 23.2 % of mild to moderately severe ADEs and 16.5 % of severe, life-threatening, or fatal ADEs. The recognition of ADEs varied with event type.

Conclusions

The recognition of ADEs by medical teams was substantial for those ADEs with evident causality and with clinically apparent and severe consequences. ADEs mimicking underlying pathologies with a lower severity went unrecognized much more often, as did those resulting only in abnormal laboratory values. Tools to improve the recognition of ADEs by medical teams should, therefore, focus on those ADEs that are more challenging to detect.

Percentage of patients with preventable adverse drug reactions and preventability of adverse drug reactions--a meta-analysis

BACKGROUND

Numerous observational studies suggest that preventable adverse drug reactions are a significant burden in healthcare, but no meta-analysis using a standardised definition for adverse drug reactions exists. The aim of the study was to estimate the percentage of patients with preventable adverse drug reactions and the preventability of adverse drug reactions in adult outpatients and inpatients.

METHODS

Studies were identified through searching Cochrane, CINAHL, EMBASE, IPA, Medline, PsycINFO and Web of Science in September 2010, and by hand searching the reference lists of identified papers. Original peer-reviewed research articles in English that defined adverse drug reactions according to WHO's or similar definition and assessed preventability were included. Disease or treatment specific studies were excluded. Meta-analysis on the percentage of patients with preventable adverse drug reactions and the preventability of adverse drug reactions was conducted.

RESULTS

Data were analysed from 16 original studies on outpatients with 48797 emergency visits or hospital admissions and from 8 studies involving 24128 inpatients. No studies in primary care were identified. Among adult outpatients, 2.0% (95% confidence interval (CI): 1.2-3.2%) had preventable adverse drug reactions and 52% (95% CI: 42-62%) of adverse drug reactions were preventable. Among inpatients, 1.6% (95% CI: 0.1-51%) had preventable adverse drug reactions and 45% (95% CI: 33-58%) of adverse drug reactions were preventable.

CONCLUSIONS

This meta-analysis corroborates that preventable adverse drug reactions are a significant burden to healthcare among adult outpatients. Among both outpatients and inpatients, approximately half of adverse drug reactions are preventable, demonstrating that further evidence on prevention strategies is required. The percentage of patients with preventable adverse drug reactions among inpatients and in primary care is largely unknown and should be investigated in future research.