Effect of barcode technology on medication preparation safety: a quasi-experimental study

BACKGROUND

Medication errors are a common problem in hospitals and a major driver of adverse patient outcomes. Barcode verification technology is a promising strategy to help ensure safe medication preparation practices.

OBJECTIVES

The objectives of this study were (i) to assess the effects of a barcode-assisted medication preparation and administration system regarding the rate of medication preparation errors and (ii) to compare the time spent on medication preparation tasks by medical staff.

METHODS

A quasi-experimental study with a pre-post design was conducted, from August 2017 to July 2018, in two mixed medical/surgical units of a tertiary teaching hospital. The primary aim was to assess the effects of a barcode-based electronically assisted medication preparation and administration system linked to the hospital's electronic medication administration record regarding the rate of medication preparation errors and time-based staff performance. Data were collected using direct observation. Adjusted and unadjusted logistic models were used for error frequencies and linear regression models for time performance.

RESULTS

5932 instances of medication selection and dosing during 79 medication preparation procedures were observed. The overall medication preparation error incidence decreased from 9.9% at baseline to 4.5% at post-intervention, corresponding to a relative risk reduction of 54.5% (P < 0.001). However, the adjusted effect by registered nurses (RNs) and nurses' work experience of total medication preparation errors showed only borderline significance (odds ratio [OR] 0.64, P = 0.051). For adjusted error-specific analyses, significant error reductions were found in wrong medication errors (OR 0.38, P < 0.010) and wrong dosage errors (OR 0.12, P = 0.004). Wrong patient, wrong form and ambiguous dispenser errors did not occur at post-intervention. Errors of omission (OR 1.53, P = 0.17), additional doses (OR 0.63, P = 0.64) and wrong dispenser boxes (OR 0.51, P = 0.11) did not change significantly. The time necessary to prepare medications for a 24-h period also decreased significantly-from 30.2 min to 17.2 min (beta = -6.5, P = 0.047), while mean preparation time per individual medication dose fell from 24.3 s to 15.1 s (beta = -5.0, P = 0.002).

CONCLUSION

Use of the new barcode technology significantly reduced the rate of some medication preparation errors in our sample. Moreover, the time necessary for medication preparation, both per 24-h period and per single-medication dose, was significantly reduced.

Translation, transcultural adaptation and validation to Brazilian Portuguese of tools for adverse drug reaction assessment in children

Background

Children are more vulnerable to adverse drug reactions (ADRs) due to complex changes in the body during the growth process and lack specific pharmacoepidemiologic studies. Causality and Avoidability assessment of ADRs are relevant to clinical guidelines development and pharmacovigilance. This study aimed to translate and transcultural adapt two new tools—Liverpool Causality Assessment Tool (LCAT) and the Liverpool Avoidability Assessment Tool (LAAT)—to Brazilian-Portuguese and evaluate the psychometric properties of these tools to analyse ADRs in Brazilian children.

Methods

The validation of the cross-cultural adaptation of tools was obtained by the functional (conceptual, semantic, operational, and measurement) equivalence between the original and translated versions of each instrument. The translated version of LCAT and LAAT was applied to assessing the twenty-six case reports of suspected adverse drug reactions in a Brazilian teaching paediatric hospital. The inter-rater reliability (a pharmacist and a physician) was evaluated using Cronbach’s alpha. The exact agreement percentages (%EA) and extreme disagreement (%ED) were computed. Overall Kappa index was calculated with a 95% confidence interval.

Results

There was a need to modify some terms translated into Portuguese for semantic and conceptual equivalence. The Cronbach’s alpha coefficient values obtained were 0.95 and 0.85, and the weighted Kappa (95% confidence interval) were 0.82 (0.67–0.97) and 0.68 (0.45–0.91) for LCAT and LAAT, respectively. The Brazilian-Portuguese versions of the LCAT and LAAT showed reliable and valid tools for the diagnosis and follow-up of ADRs in children.

Conclusion

The methodological approach allowed the translation, transcultural adaptation, and validation to Brazilian-Portuguese of two easy and quick to perform tools for causality and avoidability of ADRs in children by a multidisciplinary expert specialist committee, including the authors of original tools. We believe these versions may be applied by professionals (patient safety teams) and researchers in Brazil in groups or by a single reviewer.

Trial registration

This study was evaluated and approved by the Research Ethics Committee (Instituto de Pediatria e Puericultura Martagão Gesteira – Federal University of Rio de Janeiro – Number: 3.264.238.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01315-9.

Root causes of adverse drug events in hospitals and artificial intelligence capabilities for prevention

AIMS

To identify and prioritize the root causes of adverse drug events (ADEs) in hospitals and to assess the ability of artificial intelligence (AI) capabilities to prevent ADEs.

DESIGN

A mixed method design was used.

METHODS

A cross-sectional study for hospitals in Spain was carried out between February and April 2019 to identify and prioritize the root causes of ADEs. A nominal group technique was also used to assess the ability of AI capabilities to prevent ADEs.

RESULTS

The main root cause of ADEs was a lack of adherence to safety protocols (64.8%), followed by identification errors (57.4%), and fragile and polymedicated patients (44.4%). An analysis of the AI capabilities to prevent the root causes of ADEs showed that identification and reading are two potentially useful capabilities.

CONCLUSION

Identification error is one of the main root causes of drug adverse events and AI capabilities could potentially prevent drug adverse events.

IMPACT

This study highlights the role of AI capabilities in safely identifying both patients and drugs, which is a crucial part of the medication administration process, and how this can prevent ADEs in hospitals.

Evaluation of the nature, severity, likelihood and preventability of medication-related hospital-acquired complications

Objective Pricing for safety and quality was introduced into Australian hospitals using a defined list of hospital-acquired complications (HACs). Medication-related HACs include drug-related respiratory complications (DRRC), haemorrhagic disorder due to circulating anticoagulants (HDDCA) and hypoglycaemia. The aim of this study was to determine the probability, severity and preventability of medication-related HACs, common contributory medications and themes, and whether medication-related HACs are a suitable data source to inform risk associated with medicines use. Methods Medical notes were reviewed retrospectively for all patients discharged from a tertiary referral metropolitan hospital between 1 July and 31 December 2018 who were flagged as experiencing a medication-related HAC. Naranjo, Hartwig's and Schumock and Thornton tools were used to assess the probability, severity and preventability of medication-related HACs. Results Over the 6-month period, 88 patients experienced a medication-related HAC. An HAC was not identified in five (5.7%) patient charts. The most common HAC was hypoglycaemia (n=59; 67%), followed by HDDCA (n=23; 26%) and DRRC (n=6; 7%). Fifteen patients (17%) flagged with a hypoglycaemia HAC were not on a medicine associated with hypoglycaemia. Overall, 6% (n=4) of HACs were severe, 72% (n=49) were moderate and 22% (n=15) were mild. Where the HAC and causal medication(s) were identified (n=68), over half were probable (51.5%, n=35) and 44.1% (n=30) were possible causes of the adverse drug reaction; only two (2.9%) were definite causes. None of the DRRC HACs was preventable. Over half the HDDCA HACs (52.2%; n=12) and almost half the hypoglycaemia HACs (46.2%; n=18) were not preventable. Common themes included appropriate anticoagulant agent, dose and monitoring, as well as periprocedural hypoglycaemic management, which considers oral intake and comorbidities. Conclusion Not all patients who experience medication-related HACs were on causative medications. Of those who were, medications were probable causal agents in over 50% of cases. Only a small number of HACs were severe and under half of medication-related HACs were preventable. What is known about the topic? The relationship between pricing for safety and quality and improvements in patient outcomes has shown mixed results. Medication-related harm is a problem within Australia and system-wide changes should be considered to improve patient care. What does this paper add? This paper adds evidence to the use of medication-related HACs as a source of data to inform risk associated with medicines use and provides details on the preventability and severity of medication-related HACs and the likelihood that medicines contribute to these complications. What are the implications for practitioners? This paper provides clinicians and policy makers details on the utility of using medication-related HACs as a measure of risk associated with medicines use. It discusses merit in using HACs as a source for quality improvement, but recommends that definitions may need to be reviewed to enhance utility.

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.

[Closed-loop medication management: Results of a user survey]

BACKGROUND

New technologies, such as bar-code scanning systems, have played a significant role in enhancing medication processes over recent years. Despite the documented benefits, integration, acceptance, and user opinion continue to play an important role in the successful implementation of such systems. To date no studies have been carried out in Switzerland to assess the attitude or acceptance of nurses towards electronically supported medication systems after implementation. This study was conducted in order to close this gap.

METHODS

Following a four-month test phase of a closed-loop medication system on two mixed medical-surgical units in a tertiary teaching hospital, a cross-sectional online survey was conducted among the participating registered nurses (response rate: 62.5%).

RESULTS

The new system was evaluated positively by the majority (70%) of users. Accordingly, the barcode-assisted medication process was proven to be especially beneficial to users during the 24-hour medication preparation process and during the preparation of infusions. However, user compliance decreased significantly during the administration of bedside medication and the preparation of additional single doses. This was mainly due to a lack of time and inadequate system performance.

CONCLUSION

In the study, 75% of participants reported that they were open to or even enthusiastic about using the new technologies and were supportive of their introduction into the medication process. Overall, the majority rated the new system as beneficial to daily clinical practice, provided the technical performance was high.

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.

Severe cutaneous adverse reactions due to inappropriate medication use

BACKGROUND

The proportion of severe cutaneous adverse reactions (SCARs) that could be avoided if medication use was consistent with good medical practice is unknown.

OBJECTIVES

To estimate the proportion of SCARs related to inappropriate medication use.

METHODS

We carried out a retrospective study of all validated SCARs collected in a French registry between 2003 and 2016. For each case, all plausible drugs suspected of inducing SCARs (i.e. not just the drug regarded as 'the most probable') were considered with regard to (i) prescription for an inappropriate indication, (ii) unintentional rechallenge despite a previous allergy to the drug or (iii) self-medication with prescription medicines.

RESULTS

In total, 602 cases were included in the analyses. Antibiotics, anticonvulsants and allopurinol were the drugs most frequently involved, accounting for more than 50% of all cases. All suspected medications were considered to have been appropriately used for 417 of the 602 individuals included in the study population [69·3%, 95% confidence interval (CI) 65·6-73·0] and inappropriately used for 144 individuals (23·9%, 95% CI 20·5-27·3). These inappropriate uses were due mainly to prescriptions for an inappropriate indication (65·8%, 95% CI 58·4-73·2) or unintentional rechallenge (20·9%, 95% CI 14·6-27·2). Allopurinol and co-trimoxazole were the drugs most frequently involved in inappropriate indications. Antibiotics were the largest group involved in unintentional rechallenge. Nonsteroidal anti-inflammatory drugs, available on prescription, were most frequently involved in inappropriate self-medication.

CONCLUSIONS

Our results underline the need for respecting the appropriate indication for drugs in order to reduce the incidence of SCARs. Reducing unintentional rechallenge also seems to be a necessary preventive measure.

Association of preventable adverse drug events with inpatients' length of stay-A propensity-matched cohort study

PURPOSE

Using clinical administrative data (CAD) of inpatients, we aimed to identify ICD-10 codes coding for potentially preventable inhospital adverse drug events (ADE) that affect the length of hospital stay (LOS) and thus patient well-being and cost.

METHODS

We retrospectively assessed CAD of all inpatient stays in 2012 of a German university hospital. Predefined ICD-10 codes indicating ADE (ADE codes) were further specified based on expert ratings of the ADE mechanism and ADE preventability in clinical routine to particularly identify preventable inhospital ADE. In a propensity-matched cohort design, we compared patients with one or more ADE codes to control patients with regard to differences in LOS for three situations: all cases with an ADE code, cases with an inhospital ADE code, and cases with a preventable inhospital ADE code.

RESULTS

Out of 54 032 cases analysed, in 8.3% (N=4 462) at least one ADE code was present. Nine of 128 evaluated ADE codes were rated as preventable in clinical routine, relating to 220 inpatients (4.9% of all identified inpatients with at least one ADE code and 0.4% of the entire cohort, respectively). Out of 48 072 evaluable inpatients for propensity score matching, 7 938 controls without ADE code and 4 006 cases with ADE code were selected. In all three settings, cases showed prolonged LOS vs controls (delta 1.13 d; 0.88 d and 1.88 d, respectively), significantly exceeding the maximum LOS as defined for each Diagnosis-Related Group.

CONCLUSION

Inpatients with ADE codes referring to inhospital, potentially preventable ADE exceeded the maximum hospital stay fully reimbursed by insurance companies, indicating unnecessary long and costly inpatient stays.

Mobile App Design, Development, and Publication for Adverse Drug Reaction Assessments of Causality, Severity, and Preventability

BACKGROUND

Adverse drug reactions (ADRs) cause significant morbidity and mortality. Improved assessment of ADRs to identify the causal relationship, the severity, and the preventability will aid ADRs prevention or reduce patient burden.

OBJECTIVE

The aim of this study was to develop mobile apps in assisting clinical decision in ADR assessments of causality, severity, and preventability using validated tools. The usability of the apps was assessed.

METHODS

We designed mobile apps using validated assessment tools for ADRs. They are the Liverpool ADRs Causality Assessment Tool, Hartwig's Severity Assessment Scale, and the Modified Schumock and Thronton Preventability Scale. The apps were named "Adverse Drug ReactionCausality," "Adverse Drug ReactionSeverity," and "Adverse Drug RxnPreventability." A survey was conducted using the System Usability Scale (SUS) to assess the usability of the developed apps among health care professionals.

RESULTS

These apps are available for download through Google Play Store for free since January 2015. From the survey, the mean SUS score was 70.9 based on 26 responses from the pediatric ward of Hospital Ampang, Malaysia.

CONCLUSIONS

The developed apps received an overall acceptable usability among health care professionals. The usage of these apps will improve detection, assessment, and avoidance of future ADRs. They will also contribute to future research on ADRs, thus increasing drug safety.

Campania preventability assessment committee: a focus on the preventability of the contrast media adverse drug reactions

OBJECTIVE

The current study aims to assess the preventability of the contrast media adverse drug reactions reported through the Campania spontaneous reporting system, identifying the possible limitations emerged in this type of evaluation.

METHOD

All the individual case safety reports validated by the Campania Pharmacovigilance Regional Centre from July 2012 to September 2015 were screened to select those that reported contrast media as suspected drug. Campania Preventability Assessment Committee, in collaboration with clinicians specialized in Radiology, assessed the preventability according to the P-Method, through a case-by-case approach.

RESULTS

From July 2012 to September 2015, 13798 cases were inserted by pharmacovigilance managers in the Italian Pharmacovigilance Network database (in the geographical contest of the Campania Region), of which 67 reported contrast media as suspected drug. Five preventable cases were found. The most reported causes for preventability were the inappropriate drug use for the case clinical conditions and the absence of the preventive measure administrated prior to the contrast media administration. Several limitations were found in the evaluation of the critical criteria for the preventability assessment.

CONCLUSIONS

Educational initiatives will be organized directly to the healthcare professionals involved in the contrast media administration, to promote an appropriate use of the contrast media.

Characterization of adverse drug reactions causing admission to an intensive care unit

AIMS

This study aimed to determine the occurrence of adverse drug reactions (ADRs) that caused admission to the intensive care unit (ICU) of a university hospital.

METHODS

Clinical records were reviewed for patients meeting the inclusion criteria who were admitted to the ICU between September and December 2012. Suspected cases of ADRs were documented. Nine researchers later evaluated causality using the Naranjo Algorithm, preventability using the Schumock and Thornton criteria, and clinical classification based on the dose-time-susceptibility system.

RESULTS

In total, 96 patients presented 108 cases of ADR (13.8%, 95% confidence interval 11.2-16.4%) as the cause of admission. The most frequent ADRs were bradyarrhythmias and upper gastrointestinal bleeding (12%). Therapeutic failure accounted for 20%. The most commonly associated medications were acetylsalicylic acid (16%) and losartan (10%). Forty-six cases were categorized as possible, and only one as definite. According to the dose-time-susceptibility classification, in 82% of the cases, the dosage was collateral (within the therapeutic range), and 90% were independent of time; the factors most associated with susceptibility to ADRs were comorbidities (42%) and age (49%). Forty-four percent of the ADRs were considered possibly preventable.

CONCLUSIONS

ADRs contribute significantly to ICU admissions, and a significant number of ADRs are preventable. National studies are needed to assess their incidence and to establish classification standards to reduce their clinical impact.

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.

Adverse drug reactions

Adverse drug reactions (ADRs) remain a challenge in modern healthcare, particularly given the increasing complexity of therapeutics, an ageing population and rising multimorbidity. This article summarises some of the key facts about ADRs and explores aspects relating to their prevention, diagnosis, reporting and management in current clinical practice.

Prevalence and characteristics of adverse drug reactions at admission to hospital: a prospective observational study

Aims

Adverse drug reactions (ADRs) contribute to poorer patient outcomes and additional burden to the healthcare system. However, data on the true burden, relevant types and drugs causing ADRs are lacking. The aim of this study was to determine the prevalence of ADR‐related hospitalization in the general adult population in Singapore and to investigate their characteristics.

Methods

We prospectively recruited 1000 adult patients with unplanned admission to a large tertiary‐care hospital. Two independent reviewers evaluated all suspected ADRs for causality, type, severity and avoidability. The prevalence of ADR‐related hospitalization was calculated based on ‘definite’ and ‘probable’ ADRs. Logistic regression was used to evaluate predictors for having an ADR at admission.

Results

The prevalence of all ADRs at admission was 12.4% (95% CI: 10.5–14.6%) and ADRs causing admission was 8.1% (95% CI: 6.5–10.0%). The most common ADRs were gastrointestinal‐related. The most common drug category causing ADRs were cardiovascular drugs. Patients with ADRs had a longer length of stay than those who did not (median 4 vs. 3 days, P = 1.70 × 10⁻³). About 30% of ADRs at admission were caused by at least one drug with a clinical annotation in the Pharmacogenomics KnowledgeBase (PharmGKB), suggesting that some of these ADRs may have been predicted by pharmacogenetic testing.

Conclusions

We have quantified the burden and characteristics of clinically impactful ADRs in the Singaporean general adult population. Our results will provide vital information for efforts in reducing ADRs through targeted vigilance, patient education and pharmacogenomics in Singapore.

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.

Correlation of Incident Potentially Inappropriate Medication Prescriptions and Hospitalization: An Analysis Based on the PRISCUS List

Background

Multimorbidity and polypharmacy represent a major problem for elderly patients. Potentially inappropriate medication (PIM) use is highly prevalent among the elderly. PIMs are considered high-risk drugs and are suspected to be responsible for adverse drug events (ADEs) leading to hospitalization.

Objective

The objective of this study was to determine hospitalization rates related to selected ADEs in elderly patients with an incident prescription of a PIM as defined by the PRISCUS list. A second objective was to identify other factors independently associated with hospitalization.

Methods

We retrospectively analysed a full census of pharmaceutical claims, from one of the largest public sickness funds in Germany, for 647,073 patients aged ≥65 years in 2010, the year of publication of the PRISCUS list. Patients who received an incident PIM in 2010 were assigned to the intervention group. Propensity score matching was used to build a control group of patients at a comparable risk level who received an incident equivalent non-PIM. The risk of hospitalization due to PIM prescription was estimated via the odds ratio (OR). Risk factors were analysed via logistic regression models.

Results

The results showed significantly more ADEs in the PIM group. The OR for hospitalization was 1.54 [95 % confidence interval (CI) 1.23–1.93] for patients receiving any PIM compared with those who received a non-PIM. This trend remained stable [OR 1.46 (95 % CI 1.16–1.84)] after adjustment for relevant covariates in the logistic regression models showing ORs for each risk factor. Besides PIMs, common risk factors such as greater age, comorbidity and specific drug classes were significantly responsible for hospitalization.

Conclusion

PIMs (as defined by the PRISCUS list) are associated with high rates of ADEs associated with hospitalization. Our study suggests that PIM reduction may result in a lower risk of hospitalization in the elderly.

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.

Incidence, characteristics and risk factors of adverse drug reactions in hospitalized children - a prospective observational cohort study of 6,601 admissions

BACKGROUND

Adverse drug reactions (ADRs) are an important cause of harm in children. Current data are incomplete due to methodological differences between studies: only half of all studies provide drug data, incidence rates vary (0.6% to 16.8%) and very few studies provide data on causality, severity and risk factors of pediatric ADRs. We aimed to determine the incidence of ADRs in hospitalized children, to characterize these ADRs in terms of type, drug etiology, causality and severity and to identify risk factors.

METHODS

We undertook a year-long, prospective observational cohort study of admissions to a single UK pediatric medical and surgical secondary and tertiary referral center (Alder Hey, Liverpool, UK). Children between 0 and 16 years 11 months old and admitted for more than 48 hours were included. Observed outcomes were occurrence of ADR and time to first ADR for the risk factor analysis.

RESULTS

A total of 5,118 children (6,601 admissions) were included, 17.7% of whom experienced at least one ADR. Opiate analgesics and drugs used in general anesthesia (GA) accounted for more than 50% of all drugs implicated in ADRs. Of these ADRs, 0.9% caused permanent harm or required admission to a higher level of care. Children who underwent GA were at more than six times the risk of developing an ADR than children without a GA (hazard ratio (HR) 6.40; 95% confidence interval (CI) 5.30 to 7.70). Other factors increasing the risk of an ADR were increasing age (HR 1.06 for each year; 95% CI 1.04 to 1.07), increasing number of drugs (HR 1.25 for each additional drug; 95% CI 1.22 to 1.28) and oncological treatment (HR 1.90; 95% CI 1.40 to 2.60).

CONCLUSIONS

ADRs are common in hospitalized children and children who had undergone a GA had more than six times the risk of developing an ADR. GA agents and opiate analgesics are a significant cause of ADRs and have been underrepresented in previous studies. This is a concern in view of the increasing number of pediatric short-stay surgeries.

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.

Adverse drug reactions causing admission to a paediatric hospital

Objective(s)

To obtain reliable information about the incidence of adverse drug reactions, and identify potential areas where intervention may reduce the burden of ill-health.

Design

Prospective observational study.

Setting

A large tertiary children’s hospital providing general and specialty care in the UK.

Participants

All acute paediatric admissions over a one year period.

Main Exposure

Any medication taken in the two weeks prior to admission.

Outcome Measures

Occurrence of adverse drug reaction.

Results

240/8345 admissions in 178/6821 patients admitted acutely to a paediatric hospital were thought to be related to an adverse drug reaction, giving an estimated incidence of 2.9% (95% CI 2.5, 3.3), with the reaction directly causing, or contributing to the cause, of admission in 97.1% of cases. No deaths were attributable to an adverse drug reaction. 22.1% (95% CI 17%, 28%) of the reactions were either definitely or possibly avoidable. Prescriptions originating in the community accounted for 44/249 (17.7%) of adverse drug reactions, the remainder originating from hospital. 120/249 (48.2%) reactions resulted from treatment for malignancies. The drugs most commonly implicated in causing admissions were cytotoxic agents, corticosteroids, non-steroidal anti-inflammatory drugs, vaccines and immunosuppressants. The most common reactions were neutropenia, immunosuppression and thrombocytopenia.

Conclusions

Adverse drug reactions in children are an important public health problem. Most of those serious enough to require hospital admission are due to hospital-based prescribing, of which just over a fifth may be avoidable. Strategies to reduce the burden of ill-health from adverse drug reactions causing admission are needed.

Medication errors

Medication errors cause substantial harm to patients. We need good methods for counting errors, and we need to know how errors defined in different ways and ascertained by different methods are related to the harm that patients suffer. As errors arise within the complex and poorly designed systems of hospital and primary care, analysis of the factors that lead to error, for example by failure mode and effects analysis, may encourage better designs and reduce harms. There is almost no information on the best ways to train prescribers to be safe or to design effective computerized decision support to help them, although both are important in reducing medication errors and should be investigated. We also need to know how best to provide patients with the data they need to be part of initiatives for safer prescribing.

Costs of adverse drug events in German hospitals--a microcosting study

OBJECTIVE

In Germany, only limited data are available to quantify the attributable resource utilization associated with adverse drug events (ADEs). The aim of this study was twofold: first, to calculate the direct treatment costs associated with ADEs leading to hospitalization and, second, to derive the excess costs and extra hospital days attributable to ADEs of inpatient treatments in selected German hospitals.

METHODS

This was a retrospective and medical record-based study performed from the hospitals' perspective based on administrative accounting data from three hospitals (49,462 patients) in Germany. Total treatment costs ("analysis 1") and excess costs (i.e., incremental resource utilization) between patients suffering from an ADE and those without ADEs were calculated by means of a propensity score-based matching algorithm ("analysis 2").

RESULTS

Mean treatment costs ("analysis 1") of ADEs leading to hospitalization (n = 564) were €1,978 ± 2,036 (range €191-18,147; median €1,446; €843-2,480 [Q1-Q3]). In analysis 2, the mean costs of inpatients suffering from an ADE (n = 1,891) as a concomitant disease or complication (€5,113 ± 10,059; range €179-246,288; median €2,701; €1,636-5,111 [Q1-Q3]) were significantly higher (€970; P < 0.0001) than those of non-ADE inpatients (€4,143 ± 6,968; range €154-148,479; median €2,387; €1,432-4,701 [Q1-Q3]). Mean inpatient length of stay of ADE patients (12.7 ± 17.2 days) and non-ADE patients (9.8 ± 11.6 days) differed by 2.9 days (P < 0.0001). A nationwide extrapolation resulted in annual total treatment costs of €1.058 billion.

CONCLUSIONS

This is one of the first administrative data-based analyses calculating the economic consequences of ADEs in Germany. Further efforts are necessary to improve pharmacotherapy and relieve health care payers of preventable treatment costs.

The use of STOPP/START criteria as a screening tool for assessing the appropriateness of medications in the elderly population

Although numerous initiatives and interventions have been developed to promote medication safety, medication incidents still remain an important cause of hospitalization. To avoid this, it is important for physicians to prescribe safely. To date, the Beers criteria have been the most widely used explicit criteria for assessing the appropriateness of medications in the elderly, but they do have limitations. The more recent STOPP/START criteria were developed in the hope of addressing the deficiencies observed in the Beers criteria. This article gives an overview of STOPP/START criteria and its applications, and reviews the studies that assessed medication appropriateness using STOPP/START and/or the Beers criteria.

What is preventable harm in healthcare? A systematic review of definitions

Background

Mitigating or reducing the risk of harm associated with the delivery of healthcare is a policy priority. While the risk of harm can be reduced in some instances (i.e. preventable), what constitutes preventable harm remains unclear. A standardized and clear definition of preventable harm is the first step towards safer and more efficient healthcare delivery system. We aimed to summarize the definitions of preventable harm and its conceptualization in healthcare.

Methods

We conducted a comprehensive electronic search of relevant databases from January 2001 to June 2011 for publications that reported a definition of preventable harm. Only English language publications were included. Definitions were coded for common concepts and themes. We included any study type, both original studies and reviews. Two reviewers screened the references for eligibility and 28% (127/460) were finally included. Data collected from studies included study type, description of the study population and setting, and data corresponding to the outcome of interest. Three reviewers extracted the data. The level of agreement between the reviewers was calculated.

Results

One hundred and twenty seven studies were eligible. The three most prevalent preventable harms in the included studies were: medication adverse events (33/127 studies, 26%), central line infections (7/127, 6%) and venous thromboembolism (5/127, 4%). Seven themes or definitions for preventable harm were encountered. The top three were: presence of an identifiable modifiable cause (58/132 definitions, 44%), reasonable adaptation to a process will prevent future recurrence (30/132, 23%), adherence to guidelines (22/132, 16%). Data on the validity or operational characteristic (e.g., accuracy, reproducibility) of definitions were limited.

Conclusions

There is limited empirical evidence of the validity and reliability of the available definitions of preventable harm, such that no single one is supported by high quality evidence. The most common definition is “presence of an identifiable, modifiable cause of harm”.

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.

Adverse Drug Reactions in Hospitalized Psychiatric Patients—Comparison of Data

Objective:

To compare and contrast adverse drug reaction (ADR) reporting between 2 psychiatric hospitals, as well as preventability and possible reasons that one hospital had more preventable occurrences than the other.

Methods:

A 3-year retrospective analysis was conducted comparing ADRs previously reported in a study from Maryland Psychiatric Hospital that were classified as probable and definite according to the modified Naranjo probability scale versus probable and definite ADR reports from the Colorado Mental Health Institute at Pueblo (CMHIP). The same study period (July 1, 2006–June 30, 2009) was used for the retrospective analysis of ADRs at both institutions. We compared the most frequently reported classes of medications and examined the number of reactions, types of reactions, and preventability.

Results:

Psychiatric medications were responsible for 98/145 (67.6%) ADRs at CMHIP, while 47 (32.4%) ADRs were caused by nonpsychiatric medications. At Maryland Psychiatric Hospital, 48.4% of ADRs were caused by psychiatric medications and 51.6% were caused by nonpsychiatric medications. Of the 145 ADRs reported at CMHIP, only 1 (0.7%) was classified as preventable, versus 19 (20.4%) preventable ADRs reported in Maryland Psychiatric Hospital. The classes of medications most frequently associated with ADRs at Maryland Psychiatric Hospital were cardiovascular agents, antiepileptic drugs, and second-generation antipsychotic medications; at CMHIP the medications most commonly associated with ADRs were second-generation antipsychotics, conventional antipsychotics, and mood stabilizers. Proposed reasons for differences in numbers, types, and preventability of ADRs between the institutions are that different reporting mechanisms and pharmacy medication monitoring programs, in conjunction with quality assurance programs, were used at the 2 institutions.

Conclusions:

Differences between 2 comparable hospitals in the number and preventability of ADRs and the classes of medications reportedly responsible for them may be due to different reporting mechanisms and monitoring programs. Pharmacy intervention programs may lead to prevention of ADRs.

Multiple drug exposure as a risk factor for the seriousness of adverse drug reactions

AIM

The aim of the present study was to validate the hypothesis that multiple drug exposure is an independent risk factor for serious adverse drug reactions (ADRs).

BACKGROUND

Adverse drug reactions (ADRs) are an important cause of iatrogenic disease, the majority being preventable. Multiple drug exposure, ageing and female gender have been identified as important risk factors for an increased incidence of ADRs.

METHOD

ADR reports received by the central Portugal Regional Pharmacovigilance Unit, between January 2001 and December 2009, were studied.

RESULTS

Nearly half (47.4%) of ADRs reports were considered serious, from which 66.7% reported multiple drug exposure (mean 3.07 ± 2.2; maximum 13). After adjusting for gender, simultaneous exposure to three or more drugs was significantly associated with an increased risk of serious ADRs [odds ratio (OR) 1.23; 95% confidence interval (CI) 1.02-1.51].

CONCLUSIONS

The present results support that multiple drug exposure is an independent risk factor for serious ADRs. Such findings are of importance in both medicines benefit/risk ratio evaluations and patient safety monitoring.

IMPLICATIONS FOR NURSING MANAGEMENT

A new level of nursing involvement is needed in both the detection of ADRs and prevention of serious outcomes, particularly in high-risk patients.

Preventability of drug-related harms - part II: proposed criteria, based on frameworks that classify adverse drug reactions

BACKGROUND

'Preventability' is a crucial concept in the literature on adverse drug effects. However, a systematic review of the definitions of preventability of adverse drug effects has suggested that none fits all circumstances. Furthermore, when the reliability of these definitions has been examined they have been found to be imperfect.

OBJECTIVE

To propose and outline a method for determining the theoretical preventability of an adverse drug effect, based on frameworks for classifying adverse drug reactions - the EIDOS and DoTS methods.

METHODS

EIDOS is based on the mechanism of action of the drug. It observes that a drug (an Extrinsic species) causes an adverse effect by interacting with an Intrinsic species that is its target when the two are Distributed together, and that the resulting pathophysiological Outcome (the adverse effect) causes the Sequela (the adverse reaction). DoTS observes that the Dose-relatedness of the adverse effect compared with the beneficial effect is relevant (determining toxic, collateral, or hypersusceptibility effects), that adverse effects have Time-courses (varying from immediate to delayed), and that there are individual Susceptibility factors.

RESULTS AND DISCUSSION

We have elicited many published examples that show that each of these factors in the causation of an adverse drug effect can be adduced to assess its preventability. We have constructed a flowchart that illustrates how the processes can be logically analysed.

CONCLUSIONS

This approach suggests methods for devising prospective preventive strategies and for deciding retrospectively whether an adverse reaction in an individual should have been prevented.