Preventable adverse drug events: Descriptive epidemiology.

AIM: Our objective was to identify preventable adverse drug events and factors contributing to their development. METHODS: We performed a retrospective chart review combining data from three prospective multicentre observational studies that assessed emergency department patients for adverse drug events. A clinical pharmacist and physician independently reviewed the charts, extracted data and rated the preventability of each adverse drug event. A third reviewer adjudicated all discordant or uncertain cases. We calculated the proportion of adverse drug events that were deemed preventable, performed multivariable logistic regression to explore the characteristics of patients with preventable events, and identified contributing factors. RESULTS: We reviewed the records of 1 356 adverse drug events in 1 234 patients. Raters considered 869 (64.1%) of adverse drug events probably or definitely preventable. Patients with mental health diagnoses (OR 1.8; 95% CI 1.3-2.5) and diabetes (OR 1.7; 95% CI 1.2-2.4) were more likely to present with preventable events. The medications most commonly implicated in preventable events were warfarin (9.4%), hydrochlorothiazide (4.5%), furosemide (4.0%), insulin (3.9%) and acetylsalicylic acid (2.7%). Common contributing factors included inadequate patient instructions, monitoring and follow-up, and reassessments after medication changes had been made. CONCLUSIONS: Our study suggests that patients with mental health conditions and diabetes require close monitoring. Efforts to address the identified contributing factors are needed.

Repeat adverse drug events associated with outpatient medications: a descriptive analysis of 3 observational studies in British Columbia, Canada.

BACKGROUND: Adverse drug events are an important cause of preventable emergency department visits and hospital admissions. We examined repeat adverse drug events associated with outpatient medications resulting in acute care utilization. METHODS: This descriptive analysis combined data from 3 prospective multicentre observational studies, in which clinical pharmacists and physicians independently evaluated patients who visited the emergency department for adverse drug events in 3 hospitals in British Columbia. During these studies, an independent committee adjudicated all discordant and uncertain cases using a standardized algorithm. For the current study, we retrospectively reviewed the medical and research records of all patients 19 years of age and older who had been diagnosed with an adverse drug event during the primary studies to determine the proportion of repeat events. We used multivariable logistic regression to identify factors associated with repeat events; we adjusted for clustering at the hospital level for patient-level analyses and at the patient level for event-level analyses. RESULTS: Among 12 977 patients, 1178 were diagnosed with 1296 adverse drug events at the point of care. Of these events, 32.5% (421 of 1296; 95% confidence interval [CI] 29.8%-35.1%) were repeat events, of which 75.3% (317 of 421; 95% CI 71.1%-79.5%) were deemed probably or definitely preventable as re-exposure to the culprit medication or repeat withdrawal of an indicated medication was inconsistent with best medical practice. Patients presenting with repeat events were more likely to have renal failure (odds ratio [OR] 2.01; 95% CI 1.32%-3.07%) or a mental health diagnosis (OR 1.39; 95% CI 1.02%-1.88%). INTERPRETATION: A high proportion of adverse drug events were repeat events, most of which were deemed preventable. Interventions to ensure that care providers are aware of previously diagnosed adverse drug events when prescribing or dispensing need to be developed and evaluated and may reduce unintentional re-exposures to previously harmful medications.

Risk Factors for Misuse of Prescribed Opioids: A Systematic Review and Meta-Analysis.

STUDY OBJECTIVE: Increasing opioid prescribing has been linked to an epidemic of opioid misuse. Our objective is to synthesize the available evidence about patient-, prescriber-, medication-, and system-level risk factors for developing misuse among patients prescribed opioids for noncancer pain. METHODS: We performed a systematic search of the scientific and gray literature for studies reporting on risk factors for prescription opioid misuse. Two reviewers independently reviewed titles, abstracts, and full texts; extracted data; and assessed study quality. We excluded studies with greater than 50% cancer patients, palliative patients, and illicit opioid initiation. When possible, we synthesized the effect sizes of dichotomous risk factors and their associations with opioid misuse, using inverse-variance random-effects meta-analysis. We calculated the mean difference between opioid misusers and nonmisusers for continuous risk factors. When studies lacked homogeneity, we synthesized their results qualitatively. RESULTS: Of 9,629 studies, 65 met our inclusion criteria. Among patients with outpatient opioid prescriptions, the following factors were associated with the development of misuse: any current or previous substance use (odds ratio [OR] 3.55; 95% confidence interval [CI] 2.62 to 4.82), any mental health diagnosis (OR 2.45; 95% CI 1.91 to 3.15), younger age (OR 2.19; 95% CI 1.81 to 2.64), and male sex (OR 1.23; 95% CI 1.10 to 1.36). CONCLUSION: Although clinicians should endeavor to offer alternative pain management strategies to all patients, those who are younger, are male patients, and report a history of or current substance use or mental health diagnoses were associated with a greater risk of developing opioid misuse. Clinicians should consider prioritizing alternative pain management strategies for these higher-risk patients.

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.

Prospective Validation of Clinical Criteria to Identify Emergency Department Patients at High Risk for Adverse Drug Events.

OBJECTIVES: Adverse drug events (ADEs) cause or contribute to one in nine emergency department (ED) presentations in North America and are often misdiagnosed. EDs have insufficient clinical pharmacists to complete medication reviews in all incoming patients, even though pharmacist-led medications reviews have been associated with improved health outcomes. Our objective was to validate clinical decision rules to identify patients presenting with ADEs so they could be prioritized for pharmacist-led medication review. METHODS: This multicenter, prospective study was conducted in two tertiary and one community hospital in Canada. We enrolled 1,529 adults presenting to EDs over 12 months. We applied two clinical decision rules and collected baseline variables prior to assessments by clinical pharmacists and physicians. We compared the physician and pharmacist diagnoses with the decision rule results. The primary outcome was a moderate or severe ADE, defined as an unintended and harmful event related to medication use or misuse, which required a change in medical therapy, diagnostic testing, consultation, or admission. An independent committee adjudicated uncertain and discordant cases. We calculated the diagnostic accuracy of both rules. RESULTS: Among 1,529 patients, 184 (12.0%) were diagnosed with an ADE. Rule 1 contained the variables 1) having a preexisting medical condition or having taken antibiotics within 1 week and 2) age > 80 years or having a medication change within 28 days. They had a sensitivity of 91.3% (95% confidence interval [CI] = 86.3%-95.0%) and a specificity of 37.9% (95% CI = 35.3%-40.6%) for ADEs. CONCLUSIONS: Our study validated clinical decision rules that can be applied by clinical pharmacists to limit the number of patients requiring medication review, while identifying the majority of patients presenting with clinically significant ADEs.

Risk factors for addiction among patients receiving prescribed opioids: a systematic review protocol.

BACKGROUND: Opioid addiction prevention has become an urgent public health priority, with several countries declaring a state of emergency due to rising death tolls from opioid abuse. Reducing the risk of developing addiction among opioid-naïve patients exposed to prescribed opioids during the process of medical care may be an important primary prevention strategy. Our objective is to synthesize the available evidence about factors associated with the development of addiction among patients first exposed to prescribed opioids, with a focus on opioid-naïve patients. METHODS: We will perform a systematic search of MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and other databases in collaboration with a health information specialist using a comprehensive search strategy. We will also supplement our search with a scan of the grey literature to identify relevant ongoing and unpublished studies. We will include studies reporting on risk factors for opioid addiction in patients prescribed opioid analgesic therapy through a prescription from a licensed medical professional, with a focus on opioid-naïve patients. We will exclude studies focusing on patients who are first exposed to illicit opioids, those who use prescription opioids for cancer pain, and/or who are palliative. Two reviewers will independently review titles, abstracts, and full texts for inclusion and exclusion criteria. They will then extract data from included full texts using standardized piloted data extraction forms and assess study quality through risk of bias assessment. We will synthesize the effect sizes of risk factors derived from clinically homogenous studies with similar designs and the remaining ones qualitatively. DISCUSSION: Understanding risk factors for opioid addiction among patients who require analgesia has the potential to inform clinical care and opioid prescribing guidelines aiming to reduce opioid addiction. We will also use this information as a starting point for developing interventions for primary prevention.