Evaluating the use of prescription sequence symmetry analysis as a pharmacovigilance tool: A scoping review

Community pharmacists' awareness, identification, and management of prescribing cascades: A cross-sectional survey

BACKGROUND

Prescribing cascades can lead to unnecessary medication use, healthcare costs, and patient harm. Pharmacists oversee prescriptions from multiple prescribers and are well positioned to identify such cascades, making pharmacists key stakeholders to address them.

OBJECTIVES

To evaluate community pharmacists' awareness, identification, and management of prescribing cascades and to assess behavioural determinants that may be targeted in future strategies to minimise inappropriate prescribing cascades.

METHODS

An online survey was developed using the Theoretical Domains Framework (TDF) and emailed to all registered community pharmacists in Ireland (n = 3775) in November 2021. Quantitative data were analysed using descriptive and inferential statistics. Free-text sections were given to capture reasons for non-resolution of identified prescribing cascades and suggestions to aid prescribing cascade identification and management; this text underwent content analysis.

RESULTS

Of the 220 respondents, 51% were aware of the term 'prescribing cascade' before the survey, whilst 69% had identified a potentially inappropriate prescribing cascade in practice. Over one third were either slightly confident (26.4%) or not confident at all (10%) in their ability to identify potentially inappropriate prescribing cascades in patients' prescriptions before the survey, whilst 55.2% were concerned that patients were receiving prescribing cascades they had not identified. Most respondents wanted further information/training to help prescribing cascade identification (88.3%) and management (86.1%). Four predominant TDF domains identified were common to both i) influencing non-resolution of identified prescribing cascades and ii) in the suggestions to help identify and manage prescribing cascades: 'Environmental Context and Resources', 'Social/Professional Role and Identity', 'Social Influences' and 'Memory, Attention and Decision Processes'.

CONCLUSIONS

There is a clear need to provide additional resources to help community pharmacists identify and manage prescribing cascades. These findings will support the development of theory-informed behaviour change strategies to aid the minimisation of inappropriate prescribing cascades and decrease the risk of medication-related harm for patients.

Which older adults are at highest risk of prescribing cascades? A national study of the gabapentinoid-loop diuretic cascade

BACKGROUND

Prescribing cascades are important contributors to polypharmacy. Little is known about which older adults are at highest risk of experiencing prescribing cascades. We explored which older veterans are at highest risk of the gabapentinoid (including gabapentin and pregabalin)-loop diuretic (LD) cascade, given the dramatic increase in gabapentinoid prescribing in recent years.

METHODS

Using Veterans Affairs and Medicare claims data (2010-2019), we performed a prescription sequence symmetry analysis (PSSA) to assess loop diuretic initiation before and after gabapentinoid initiation among older veterans (≥66 years). To identify the cascade, we calculated the adjusted sequence ratio (aSR), which assesses the temporality of LD relative to gabapentinoid initiation. To explore high-risk groups, we used multivariable logistic regression with prescribing order modeled as a binary dependent variable. We calculated adjusted odds ratios (aORs), measuring the extent to which factors are associated with one prescribing order versus another.

RESULTS

Of 151,442 veterans who initiated a gabapentinoid, there were 1,981 patients who initiated a LD within 6 months after initiating a gabapentinoid compared to 1,599 patients who initiated a LD within 6 months before initiating a gabapentinoid. In the gabapentinoid-LD group, the mean age was 73 years, 98% were male, 13% were Black, 5% were Hispanic, and 80% were White. Patients in each group were similar across patient and health utilization factors (standardized mean difference <0.10 for all comparisons). The aSR was 1.23 (95% CI: 1.13, 1.34), strongly suggesting the cascade's presence. People age ≥85 years were less likely to have the cascade (compared to 66-74 years; aOR 0.74, 95% CI: 0.56-0.96), and people taking ≥10 medications were more likely to have the cascade (compared to 0-4 drugs; aOR 1.39, 95% CI: 1.07-1.82).

CONCLUSIONS

Among older adults, those who are younger and taking many medications may be at higher risk of the gabapentinoid-LD cascade, contributing to worsening polypharmacy and potential drug-related harms. We did not identify strong predictors of this cascade, suggesting that prescribing cascade prevention efforts should be widespread rather than focused on specific subgroups.

Detection of iodixanol-induced allergic reaction signals in Chinese inpatients: a multi-center retrospective database study using prescription sequence symmetry analysis

Objective

This study aimed to explore the signal detection method for allergic reactions induced by inpatient iodixanol injection.

Methods

A database of 3,719,217 hospitalized patients from 20 large Chinese general hospitals was processed and analyzed using the prescription sequence symmetry analysis (PSSA) method.

Results

126,680 inpatients who used iodixanol and were concurrently treated with anti-allergic drugs were analyzed. In the medical records of these patients, only 32 had documented iodixanol allergies. Statistical analysis identified 22 drugs in 4 categories-calcium preparations, adrenergic/dopaminergic agents, glucocorticoids, and antihistamines-as marker drugs. With time intervals of 3, 7, and 28 days, the adjusted sequence ratios (aSRs) for all anti-allergics and the 4 categories were greater than 1. The 7-day aSRs were 2.12 (95% CI: 2.08-2.15), 1.70 (95% CI: 1.68-1.73), 3.85 (95% confidence interval [CI]: 3.75-2.30), 2.30 (95% CI: 2.26-2.35), and 1.95 (95% CI: 1.89-2.02), respectively. The proportions of adverse drug events indicated by each signal were as follows: all anti-allergics (2.92%-3%), calcium gluconate (0.19%-0.52%), adrenergic/dopaminergic agents (2.20%-3.37%), glucocorticoids (3.13%-3.76%), and antihistamines (1.05%-1.32%).

Conclusion

This first multi-center Chinese inpatient database study detected iodixanol-induced allergy signals, revealing that reactions may be much higher than those in collected spontaneous reports. Iodixanol risk exposure was closer to actual pharmaceutical care findings. PSSA application with ≤7-day intervals appears better suited for monitoring late allergic reaction signals with these drugs.

Is the sequence ratio an unbiased estimate of the incidence rate ratio? A simulation study

PURPOSE

We aimed to evaluate the conditions under which the sequence ratio (SR) obtained from a sequence symmetry analysis is an unbiased estimate of the true incidence rate ratio (IRR).

METHODS

We simulated cohorts of 1 million individuals who could initiate an exposure drug and experience a very rare, rare, common, or frequent outcome of interest. The outcome rate among exposed individuals was modified by a true incidence rate ratio of 0.2, 0.5, 1.0, 2.0, and 5.0. We further evaluated scenarios where the outcome was fatal and led to immediate censoring or the outcome reduced the rate of initiation of the exposure drug.

RESULTS

We found the SR to be close to unbiased for rare, common, and frequent events, except when the true IRR was 5.0 (mean SR 4.94 and 3.74 for common and frequent events). The SR was slightly biased when the outcome was very rare. When the outcome was potentially fatal, the SR was increasingly biased with an increasing probability of death. Likewise, when the outcome reduced the probability of future exposure, the SR was upwards biased.

CONCLUSION

The SR is a biased estimate of the incidence rate ratio, when the true IRR is high, the outcome has a high mortality, or when the outcome reduces the probability of future exposure.

Risk of gout flare after medication: prescription symmetry sequence analysis

OBJECTIVES

The research aimed to study the following questions: (1) five well-known gout-related medications were selected to test the validity of the prescription symmetry sequence analysis in Taiwan; (2) four exploratory medications were selected to test their relation to gout flares.

METHODS

We utilized the 2003-2017 dataset of the Taiwan National Health Insurance Program containing all claims data with 2 million beneficiaries as a data source. In order to explore the temporal association, we designed a scenario of medication-induced gout flares. Nine medications were selected as the index agent, including aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol, pyrazinamide, metformin, pioglitazone, fenofibrate, and losartan. The gout flare was defined as subjects with use of the marker agent for treatment of gout flares. The observation-window period between initiation of the index agent and initiation of the marker agent was 1 year. Subjects who used an index agent and a marker agent on the same day were excluded. The prescription symmetry sequence analysis was carried out to compare the observed number of persons who took an index agent prior to starting a marker agent with the observed number of persons who took a marker agent before starting an index agent. The adjusted sequence ratio (adjusted SR) with 95% confidence interval was applied to estimate the relation between an index agent and the marker agent.

RESULTS

Among five medications including aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol, and pyrazinamide, the adjusted sequence ratio ranged from 1.15 to 3.35 and all reached statistical significance. Fenofibrate use and losartan use were associated with a lower probability of gout flares, with reaching statistical significance (adjusted SR = 0.60 for fenofibrate and adjusted SR = 0.92 for losartan). Metformin use was associated with a greater probability of gout flares, with reaching statistical significance (adjusted SR = 1.14). Pioglitazone use did not reach statistical significance.

CONCLUSION

Based on the confirmatory analysis including five well-known gout-related medications, this study supports that the prescription symmetry sequence analysis can be used to detect an adverse drug event associated with one potential offending agent. The exposure to fenofibrate or losartan might be a protective factor against gout flares. Metformin use could be associated with a greater probability of gout flares, but this finding should be validated by other studies.

KEY POINTS

• What is already known about this subject? 1. The prescription symmetry sequence analysis is a useful method for detecting an adverse drug reaction associated with one potential offending drug. 2. Numerous medications are found to induce gout flares. • What does this study add? 1. The prescription symmetry sequence analysis supports the evidence that aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol and pyrazinamide are associated with a greater probability of gout flares. 2. The exposure to fenofibrate or losartan might be a protective factor against gout flares. 3. Metformin use could be associated with a greater probability of gout flares. • How might this impact on clinical practice or future developments? 1. Clinicians should always consider the possibility of medication-induced gout flares. If gout flares develop, discontinuation of risky medications is the first step. Then prescribing cascades can be eliminated.

Association of a calcium channel blocker and diuretic prescribing cascade with adverse events: A population-based cohort study

BACKGROUND

Prescribing cascades occur when a drug adverse event is misinterpreted as a new medical condition and a second, potentially unnecessary drug, is prescribed to treat the adverse event. The population-level consequences of prescribing cascades remain unknown.

METHODS

This population-based cohort study used linked health administrative databases in Ontario, Canada. The study included community-dwelling adults, 66 years of age or older with hypertension and no history of heart failure (HF) or diuretic use in the prior year, newly dispensed a calcium channel blocker (CCB). Individuals subsequently dispensed a diuretic within 90 days of incident CCB dispensing were classified as the prescribing cascade group, and compared to those not dispensed a diuretic, classified as the non-prescribing cascade group. Those with and without a prescribing cascade were matched one-to-one on the propensity score and sex. The primary outcome was a serious adverse event (SAE), which was the composite of emergency room visits and hospitalizations in the 90-day follow-up period. We estimated hazard ratios (HRs) with 95% confidence intervals (CI) for SAE using an Andersen-Gill recurrent events regression model.

RESULTS

Among 39,347 older adults with hypertension and no history of HF who were newly dispensed a CCB, 1881 (4.8%) had a new diuretic dispensed within 90 days after CCB initiation. Compared to the non-prescribing cascade group, those in the prescribing cascade group had higher rates of SAEs (HR: 1.21, 95% CI: 1.02-1.43).

CONCLUSIONS

The CCB-diuretic prescribing cascade was associated with an increased rate of SAEs, suggesting harm beyond prescribing a second drug therapy. Our study raises awareness of the downstream impact of the CCB-diuretic prescribing cascade at a population level and provides an opportunity for clinicians who identify this prescribing cascade to review their patients' medications to determine if they can be optimized.

Evaluating Provider and Pharmacy Discordance in Potential Calcium Channel Blocker-Loop Diuretic Prescribing Cascade

BACKGROUND

Prescribing cascades occur when a drug-induced adverse event is treated with a new medication. Identifying clinical scenarios in which prescribing cascades are more likely to occur may help determine ways to prevent prescribing cascades.

OBJECTIVE

To understand the extent to which discordant providers and discordant pharmacies contribute to the dihydropyridine calcium channel blocker (DH CCB)-loop diuretic prescribing cascade.

STUDY POPULATION AND DESIGN

A retrospective cohort study using Medicare Fee-For-Service data (2011-2018) of adults aged ≥ 66 years.

EXPOSURES

Patients who initiated DH CCB with subsequent initiation of loop diuretic (DH CCB-loop diuretic dyad) within 90 days or patients who initiated angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) with subsequent initiation of a loop diuretic (ACEI/ARB-loop diuretic dyad; control).

MAIN OUTCOMES

The primary outcomes were provider and pharmacy discordance for prescribing cascades and control drug pairs. Baseline clinical and socio-demographic characteristics were balanced using inverse probability of treatment weighting with propensity scores.

RESULTS

 Overall, we identified 1987 DH CCB-loop diuretic dyads and 3148 ACEI/ARB-loop diuretic dyads. Discordant providers occurred in 64% of DH CCB-loop diuretic dyads and 55% of ACEI/ARB-loop diuretic dyads, while discordant pharmacies occurred in 19% of DH CCB-loop diuretic dyads and 16% of ACEI/ARB-loop diuretic dyads. After adjustment, the risk of having discordant providers was 20% {Relative Risk (RR) 1.20 [95% confidence interval (CI), 1.14-1.26]} higher in the DH CCB-loop diuretic dyad compared with the ACEI/ARB-loop diuretic dyad. Moreover, pharmacy discordance was 17% (RR 1.17 [95% CI 1.02-1.33]) higher.

CONCLUSION

Our findings suggest that discordant providers and discordant pharmacies were more commonly involved in the potential prescribing cascade when compared with a similar control dyad of medications. Opportunities for enhanced care coordination and medication reconciliation should be explored to prevent unnecessary polypharmacy.

Prescription Sequence Symmetry Analysis (PSSA) to assess prescribing cascades: a step-by-step guide

Prescribing cascades occur when patients are prescribed medication to treat the adverse drug reaction of previously prescribed medication. Prescription sequence symmetry analysis (PSSA) can be used to assess the association between two medications in prescription or dispensing databases and thus the potential occurrence of prescribing cascades. In this article, a step-by-step guide is presented for conducting PSSA to assess prescribing cascades. We describe considerations for medication data collection and setting time periods for relevant parameters, including washout window, exposure window, continued exposure interval and blackout period. With two examples, we illustrate the impact of changes in these parameters on the strengths of associations observed. Given the impact seen, we recommend that researchers clearly specify and explain all considerations regarding medication included and time windows set when studying prescribing cascades with PSSA, and conduct subgroup and sensitivity analyses.

Mapping potentially inappropriate medications in older adults using the Anatomical Therapeutic Chemical (ATC) classification system

BACKGROUND

Potentially inappropriate medications (PIMs) in older adults are medications in which risks often outweigh benefits and are suggested to be avoided. Worldwide, many distinct guidelines and tools classify PIMs in older adults. Collating these guidelines and tools, mapping them to a medication classification system, and creating a crosswalk will enhance the utility of PIM guidance for research and clinical practice.

METHODS

We used the Anatomical Therapeutic Chemical (ATC) Classification System, a hierarchical classification system, to map PIMs from eight distinct guidelines and tools (2019 Beers Criteria, Screening Tool for Older Person's Appropriate Prescriptions [STOPP], STOPP-Japan, German PRISCUS, European Union-7 Potentially Inappropriate Medication [PIM] list, Centers for Medicare & Medicaid Services [CMS] High-Risk Medication, Anticholinergic Burden Scale, and Drug Burden Index). Each PIM was mapped to ATC Level 5 (drug) and to ATC Level 4 (drug class). We then used the crosswalk (1) to compare PIMs and PIM drug classes across guidelines and tools to determine the number of PIMs that were index (drug-induced adverse event) or marker (treatment of drug-induced adverse event) drug of prescribing cascades, and (2) estimate the prevalence of PIM use in older adults continuously enrolled with fee-for-service Medicare in 2018 as use cases. Data visualization and descriptive statistics were used to assess guidelines and tools for both use cases.

RESULTS

Out of 480 unique PIMs identified, only three medications-amitriptyline, clomipramine, and imipramine and two drug classes-N06AA (tricyclic antidepressants) and N06AB (selective serotonin reuptake inhibitors), were noted in all eight guidelines and tools. Using the crosswalk, 50% of classes of index drugs and 47% of classes of marker drugs of known prescribing cascades were PIMs. Additionally, 88% of Medicare beneficiaries were dispensed ≥1 PIM across the eight guidelines and tools.

CONCLUSION

We created a crosswalk of eight PIM guidelines and tools to the ATC classification system and created two use cases. Our findings could be used to expand the ease of PIM identification and harmonization for research and clinical practice purposes.

Association between Incidence of Prescriptions for Alzheimer's Disease and Beta-Adrenoceptor Antagonists: A Prescription Sequence Symmetry Analysis

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia, with a growing number of patients worldwide. The association between AD and treatment with drugs targeting the beta-adrenergic receptor is controversial. The aim of this study is to assess the association between the initiation of AD medication and beta-adrenoceptor antagonists (beta-blockers) in adults.

MATERIALS AND METHODS

We conducted a prescription sequence symmetry analysis using the University of Groningen IADB.nl prescription database. We determined the order of the first prescription for treating AD and the first prescription for beta-blockers, with the dispensing date of the first prescription for AD defined as the index date. Participants were adults over 45 years old starting any AD medication and beta-blockers within two years. We calculated adjusted sequence ratios with corresponding 95% confidence intervals.

RESULTS

We identified 510 users of both AD and beta-blockers, and 145 participants were eligible. The results were compatible with either a significant decrease in the incidence of AD after using beta-blockers (adjusted sequence ratio (aSR) = 0.52; 95% CI: 0.35-0.72) or, conversely, an increase in beta-blockers after AD medication (aSR = 1.96; 95% CI: 1.61-2.30).

CONCLUSIONS

There is a relationship between the use of beta-blockers and AD medications. Further research is needed with larger populations to determine whether drug therapy for AD increases the risk of hypertension or whether beta-blockers have potential protective properties against AD development.

Prescribing Cascades with Recommendations to Prevent or Reverse Them: A Systematic Review

BACKGROUND

To reduce prescribing cascades occurring in clinical practice, healthcare providers require information on the prescribing cascades they can recognize and prevent.

OBJECTIVE

This systematic review aims to provide an overview of prescribing cascades, including dose-dependency information and recommendations that healthcare providers can use to prevent or reverse them.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed. Relevant literature was identified through searches in OVID MEDLINE, OVID Embase, OVID CINAHL, and Cochrane. Additionally, Web of Science and Scopus were consulted to analyze reference lists and citations. Publications in English were included if they analyzed the occurrence of prescribing cascades. Prescribing cascades were included if at least one study demonstrated a significant association and were excluded when the adverse drug reaction could not be confirmed in the Summary of Product Characteristics. Two reviewers independently extracted and grouped similar prescribing cascades. Descriptive summaries were provided regarding dose-dependency analyses and recommendations to prevent or reverse these prescribing cascades.

RESULTS

A total of 95 publications were included, resulting in 115 prescribing cascades with confirmed adverse drug reactions for which at least one significant association was found. For 52 of these prescribing cascades, information regarding dose dependency or recommendations to prevent or reverse prescribing cascades was found. Dose dependency was analyzed and confirmed for 12 prescribing cascades. For example, antipsychotics that may cause extrapyramidal syndrome followed by anti-parkinson drugs. Recommendations focused on dosage lowering, discontinuing medication, and medication switching. Explicit recommendations regarding alternative options were given for three prescribing cascades. One example was switching to ondansetron or granisetron when extrapyramidal syndrome is experienced using metoclopramide.

CONCLUSIONS

In total, 115 prescribing cascades were identified and an overview of 52 of them was generated for which recommendations to prevent or reverse them were provided. Nonetheless, information regarding alternative options for managing prescribing cascades was scarce.

High-throughput screening for prescribing cascades among real world statin initiators

PURPOSE

Statins are among the most prevalent medications prescribed and associated with adverse events that may prompt additional treatment (i.e., a prescribing cascade). No comprehensive assessment of statin-related prescribing cascades has been performed to our knowledge.

METHODS

We utilized sequence symmetry analysis to iteratively screen prescribing sequences of all therapeutic classes ("marker" classes) based on Level 4 Anatomical Therapeutic Chemical codes among adult statin initiators, using IBM Marketscan commercial and Medicare supplemental claims databases (2005-2019). Order of initiation and secular trend-adjusted sequence ratios were calculated for each statin-marker class dyad, among marker class initiators ±90 days of statin initiation. Among signals classified as prescribing cascades, we calculated naturalistic number needed to harm (NNTH) within 1 year as the inverse of the excess risk among exposed.

RESULTS

We identified 2 265 519 statin initiators (mean ± SD age, 56.4 ± 12.0 years; 48.7% women; 7.5% with cardiovascular disease). Simvastatin (34.4% of statin initiators) and atorvastatin (33.9%) were the most commonly initiated statins. We identified 160 significant statin-marker class dyad signals, of which 35.6% (n = 57) were classified as potential prescribing cascades. Of the top 25 strongest signals (lowest NNTH), 12 were classified as potential prescribing cascades, including osmotically acting laxatives (NNTH, 44, 95% CI 43-46), opioids + non-opioid combination analgesics (81, 95% CI 74-91), and first-generation cephalosporins (204, 95% CI 175-246).

CONCLUSIONS

Using high-throughput sequence symmetry analysis screening, we identified previously known prescribing cascades as well as potentially new prescribing cascades based on known and unknown statin-related adverse events.

Early Detection of Adverse Drug Reaction Signals by Association Rule Mining Using Large-Scale Administrative Claims Data

INTRODUCTION

Adverse drug reactions (ADRs) are a leading cause of mortality worldwide and should be detected promptly to reduce health risks to patients. A data-mining approach using large-scale medical records might be a useful method for the early detection of ADRs. Many studies have analyzed medical records to detect ADRs; however, most of them have focused on a narrow range of ADRs, limiting their usefulness.

OBJECTIVE

This study aimed to identify methods for the early detection of a wide range of ADR signals.

METHODS

First, to evaluate the performance in signal detection of ADRs by data-mining, we attempted to create a gold standard based on clinical evidence. Second, association rule mining (ARM) was applied to patient symptoms and medications registered in claims data, followed by evaluating ADR signal detection performance.

RESULTS

We created a new gold standard consisting of 92 positive and 88 negative controls. In the assessment of ARM using claims data, the areas under the receiver-operating characteristic curve and the precision-recall curve were 0.80 and 0.83, respectively. If the detection criteria were defined as lift > 1, conviction > 1, and p-value < 0.05, ARM could identify 156 signals, of which 90 were true positive controls (sensitivity: 0.98, specificity: 0.25). Evaluation of the capability of ARM with short periods of data revealed that ARM could detect a greater number of positive controls than the conventional analysis method.

CONCLUSIONS

ARM of claims data may be effective in the early detection of a wide range of ADR signals.

Prescribing Cascades: How to Detect Them, Prevent Them, and Use Them Appropriately

BACKGROUND

A prescribing cascade is the treatment of an adverse drug reaction (ADR) with another drug. In this review, we discuss (a) the different types of prescribing cascade and (b) the measures that can be taken so that they will be recognized and dealt with appropriately, both in the hospital and in the outpatient setting.

METHODS

This review is based on pertinent publications retrieved by a selective literature search.

RESULTS

The literature distinguishes intentional from unintentional prescribing cascades, and appropriate from inappropriate ones. We further distinguish prophylactic from therapeutic prescribing cascades and draw a line between those that are necessary and those that are merely appropriate. The following main questions are essential for dealing with prescribing cascades appropriately: (1) Did the precipitating drug cause a clinically relevant ADR or risk of an ADR? (2) Is the precipitating drug still indicated? (3) Can an ADR be avoided by altering the treatment with the precipitating drug, or by (4) switching to another drug instead? (5) Can the drug used to treat the ADR actually affect it beneficially? (6) Do the benefits of the prescribing cascade outweigh its risks?

CONCLUSION

Prescribing cascades are not problematic in themselves; on the contrary, they are sometimes a necessary part of good prescribing practice. There is still a lack of practically implementable instruments to help physicians detect prescribing cascades reliably, assess them properly, and put them to appropriate use.

Prescribing cascades in community-dwelling adults: A systematic review

The misattribution of an adverse drug reaction (ADR) as a symptom or illness can lead to the prescribing of additional medication, referred to as a prescribing cascade. The aim of this systematic review is to identify published prescribing cascades in community-dwelling adults. A systematic review was reported in line with the PRISMA guidelines and pre-registered with PROSPERO. Electronic databases (Medline [Ovid], EMBASE, PsycINFO, CINAHL, Cochrane Library) and grey literature sources were searched. Inclusion criteria: community-dwelling adults; risk-prescription medication; outcomes-initiation of new medicine to "treat" or reduce ADR risk; study type-cohort, cross-sectional, case-control, and case-series studies. Title/abstract screening, full-text screening, data extraction, and methodological quality assessment were conducted independently in duplicate. A narrative synthesis was conducted. A total of 101 studies (reported in 103 publications) were included. Study sample sizes ranged from 126 to 11 593 989 participants and 15 studies examined older adults specifically (≥60 years). Seventy-eight of 101 studies reported a potential prescribing cascade including calcium channel blockers to loop diuretic (n = 5), amiodarone to levothyroxine (n = 5), inhaled corticosteroid to topical antifungal (n = 4), antipsychotic to anti-Parkinson drug (n = 4), and acetylcholinesterase inhibitor to urinary incontinence drugs (n = 4). Identified prescribing cascades occurred within three months to one year following initial medication. Methodological quality varied across included studies. Prescribing cascades occur for a broad range of medications. ADRs should be included in the differential diagnosis for patients presenting with new symptoms, particularly older adults and those who started a new medication in the preceding 12 months.

ThinkCascades: A Tool for Identifying Clinically Important Prescribing Cascades Affecting Older People

BACKGROUND AND OBJECTIVE

Prescribing cascades occur when a drug is prescribed to manage side effects of another drug, typically when a side effect is misinterpreted as a new condition. A consensus list of clinically important prescribing cascades that adversely affect older persons' health (i.e., where risks of the prescribing cascade usually exceed benefits) was developed to help identify, prevent, and manage prescribing cascades.

METHODS

Three rounds of a modified Delphi process were conducted with a multidisciplinary panel of 38 clinicians from six countries with expertise in geriatric pharmacotherapy. The clinical importance of 139 prescribing cascades was assessed in Round 1. Cascades highly rated by ≥ 70% of panelists were included in subsequent rounds. Factors influencing ratings in Rounds 1 and 3 were categorized. After three Delphi rounds, highly rated prescribing cascades were reviewed by the study team to determine the final list of clinically important cascades consistent with potentially inappropriate prescribing.

RESULTS

After three rounds, 13 prescribing cascades were highly rated by panelists. Following a study team review, the final tool includes nine clinically important prescribing cascades consistent with potentially inappropriate prescribing. Panelists reported that their ratings were influenced by many factors (e.g., how commonly they encountered the medications involved and the cascade itself, the severity of side effects, availability of alternatives). The relative importance of these factors in determining clinical importance varied by panelist.

CONCLUSIONS

A nine-item consensus-based list of clinically important prescribing cascades, representing potentially inappropriate prescribing, was developed. Panelists' decisions about what constituted a clinically important prescribing cascade were multi-factorial. This tool not only raises awareness about these cascades but will also help clinicians recognize these and other important prescribing cascades. This list contributes to the prevention and management of polypharmacy and medication-related harm in older people.

“Kind of blurry”: Deciphering clues to prevent, investigate and manage prescribing cascades

Background

Prescribing cascades, where a medication is used to treat the side effect of another medication, contribute to polypharmacy and related morbidity. Little is known about clinicians’ and patients’ experiences with prescribing cascades. In this study, we explored why and how prescribing cascades occur across a variety of care settings and how they are managed.

Methods and findings

This descriptive qualitative study employed semi-structured interviews with older adults who may have experienced a prescribing cascade(s), their caregivers, and healthcare providers. Interviewees were recruited through physician referral from a Geriatric Day Hospital, two long-term care homes in Ottawa, Ontario, and through self-referral across Ontario, Canada. An inductive approach was used to code data and determine themes. Thirty-one interviews were conducted for ten unique patient cases. Some interviewees were involved in more than one case, resulting in 22 unique interviewees. Three themes were identified. First, recognition of prescribing cascades is linked to awareness of medication side effects. Second, investigation and management of prescribing cascades is simultaneous and iterative (rather than linear and sequential). Third, prevention of prescribing cascades requires intentional strategies to help people anticipate and recognize medication side effects. Difficulty with recruitment from both long-term care homes and through self-referral was the central limitation. This exemplifies challenges associated with studying a poorly recognized and underexplored phenomenon.

Conclusions

In order to better recognize, investigate and manage prescribing cascades, clinicians and patients need to know more about medication side effects; they need to ask ‘can this be caused by a drug?’ when signs and symptoms arise or worsen; and they need access to information about medication experiences to have benefit-risk discussions and make decisions about deprescribing. Approaches for raising public awareness of prescribing cascades should be trialed to raise the profile of this issue and facilitate continued exploration of the phenomenon.

Evaluation of a Beta-Blocker-Edema-Loop Diuretic Prescribing Cascade: A Prescription Sequence Symmetry Analysis

BACKGROUND

Drug-related adverse events associated with antihypertensive therapy may result in subsequent prescribing of other potentially harmful medications, known as prescribing cascades. The aim of this study was to assess the magnitude and characteristics of a beta-blocker-edema-loop diuretic prescribing cascade.

METHODS

A prescription sequence symmetry analysis was used to assess loop diuretic initiation before and after initiation of beta-blockers among patients 20 years or older without heart failure, atrial fibrillation, other arrythmias, or use of calcium channel blocker within a U.S. private insurance claims database (2005-2018). The temporality of loop diuretic initiation relative to a beta-blocker or negative control (renin-angiotensin system blocker) initiation was tabulated. Secular trend-adjusted sequence ratios (aSRs) with 95% confidence intervals (CIs) compared the initiation of loop diuretic 90 days before and after initiation of beta-blockers.

RESULTS

Among 988,675 beta-blocker initiators, 9,489 patients initiated a new loop diuretic prescription 90 days after and 5,245 patients before beta-blocker initiation, resulting in an aSR of 1.78 (95% CI, 1.72-1.84). An estimated 1.72 beta-blocker initiators per 100 patient-years experienced the prescribing cascade in the first 90 days. The aSR was disproportionately higher among older adults (aSR 1.97), men (aSR 2.25), and patients who initiated metoprolol tartrate (aSR 2.48), labetalol (aSR 2.18), or metoprolol succinate (aSR 2.11). Negative control results (aSR 1.09, 95% CI, 1.05-1.13) generally corroborated our findings, but suggested modest within-person time-varying confounding.

CONCLUSIONS

We observed excess use of loop diuretics following beta-blocker initiation that was only partially explained by secular trends or hypertension progression.

Association between gabapentinoids and oedema treated with loop-diuretics: a pooled sequence symmetry analysis from the United States and Denmark

AIMS

To assess the gabapentinoid-oedema-loop diuretic prescribing cascade in adults using large administrative health care databases from the US and Denmark.

METHODS

This study used a sequence symmetry analysis to assess loop diuretic initiation before and after the initiation of gabapentinoids among patients aged 20 years or older without heart failure or chronic kidney disease. Data from MarketScan Commercial and Medicare Supplemental Claims databases (2005 to 2019) and Danish National Prescription Register (2005 to 2018) were analyzed. Use of loop diuretics associated with initiation of selective norepinephrine reuptake inhibitors (SNRI) was used as a negative control. We assessed the pooled temporality of loop diuretic initiation relative to gabapentinoid or SNRI initiation across the two countries. Secular trend-adjusted sequence ratios (aSRs) with 95% Cis were calculated using data from 90 days before and after initiation of gabapentinoids. Pooled ratio of aSRs were calculated by comparing gabapentinoids to SNRIs.

RESULTS

Among the 1,511,493 gabapentinoid initiators (Denmark [n=338,941]; United States [n=1,172,552]), 20,139 patients had a new loop diuretic prescription 90 days before or after gabapentinoid initiation, resulting in a pooled aSR of 1.33 (95% CI 1.06-1.67). The pooled aSR for the negative control (i.e., SNRI) was 0.84 (95% CI 0.75-0.94), which resulted in a pooled ratio of aSRs of 1.58 (95% CI 1.23-2.04). Pooled estimated incidence of the gabapentinoid-loop diuretic prescribing cascade was 8.14 (95% CI, 1.92-34.49) events per 1000 patient years.

CONCLUSION

We identified evidence of the gabapentinoid-oedema-loop diuretic prescribing cascade in two countries.

Evaluation of the key prescription sequence symmetry analysis assumption using the calcium channel blocker: Loop diuretic prescribing cascade

OBJECTIVES

To evaluate the prescription sequence symmetry analysis assumption regarding balance between marker drug (i.e., medication used to treat a drug-induced adverse event) initiation rates before and after initiation of an index drug (i.e., medication that is potentially associated with the drug-induced adverse event) in the absence of prescribing cascades, we used a well-described example of loop diuretic initiation to treat dihydropyridine calcium channel blockers (DH CCB)-induced edema.

STUDY DESIGN AND SETTING

The University of Florida Health Integrated Data Repository from June 2011 and July 2018 was used to assess temporal prescribing of DH CCB and loop diuretics within the prescription sequence symmetry analysis framework. Validation of the prescribing cascade was performed via clinical expert chart review.

RESULTS

Among patients without heart failure who were initiated on DH CCB, 26 and 64 loop diuretics initiators started within 360 days before versus after DH CCB initiation, respectively, resulting in an adjusted sequence ratio (aSR) of 2.27 (95% CI, 1.44-3.58). Overall, 35 (54.7%) patients were determined to have a prescribing cascade. Removing patients who experienced a prescribing cascade resulted in an aSR of 1.05, 95% CI 0.62-1.78).

CONCLUSION

Loop diuretic initiation rates before and after DH CCB initiation for reasons other a prescribing cascade were similar, thus confirming the prescription sequence symmetry analysis assumption.