Pharmacoepidemiological safety studies in children: a systematic review

Using Natural Language Processing Techniques to Detect Adverse Events From Progress Notes Due to Chemotherapy

Objective:

In recent years, natural language processing (NLP) techniques have progressed, and their application in the medical field has been tested. However, the use of NLP to detect symptoms from medical progress notes written in Japanese, remains limited. We aimed to detect 2 gastrointestinal symptoms that interfere with the continuation of chemotherapy—nausea/vomiting and diarrhea—from progress notes using NLP, and then to analyze factors affecting NLP.

Materials and methods:

In this study, 200 patients were randomly selected from 5277 patients who received intravenous injections of cytotoxic anticancer drugs at Kagawa University Hospital, Japan, between January 2011 and December 2018. We aimed to detect the first occurrence of nausea/vomiting (Group A) and diarrhea (Group B) using NLP. The NLP performance was evaluated by the concordance with a review of the physicians’ progress notes used as the gold standard.

Results:

Both groups showed high concordance: 83.5% (95% confidence interval [CI] 74.1-90.1) in Group A and 97.7% (95% CI 91.3-99.9) in Group B. However, the concordance was significantly better in Group B ( P = .0027). There were significantly more misdetection cases in Group A than in Group B (15.3% in Group A; 1.2% in Group B, P = .0012) due to negative findings or past history.

Conclusion:

We detected occurrences of nausea/vomiting and diarrhea accurately using NLP. However, there were more misdetection cases in Group A due to negative findings or past history, which may have been influenced by the physicians’ more frequent documentation of nausea/vomiting.

Association of Selective Serotonin Reuptake Inhibitors With the Risk of Type 2 Diabetes in Children and Adolescents

IMPORTANCE

Concerns exist that use of selective serotonin reuptake inhibitors (SSRIs) increases the risk of developing type 2 diabetes (T2D) in adults, but evidence in children and adolescents is limited. In the absence of a randomized clinical trial, evidence must be generated using real-world data.

OBJECTIVE

To evaluate the safety of SSRI use in children and adolescents with respect to the associated risk of T2D.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of patients aged 10 to 19 years with a diagnosis for an SSRI treatment indication was conducted within the nationwide Medicaid Analytic eXtract (MAX; January 1, 2000, to December 31, 2014) and the IBM MarketScan (January 1, 2003, to September 30, 2015) databases. Data were analyzed from November 1, 2018, to December 6, 2019.

EXPOSURES

New users of an SSRI medication and comparator groups with no known metabolic adverse effects (no antidepressant exposure, bupropion hydrochloride exposure, or psychotherapy exposure). Within-class individual SSRI medications were compared with fluoxetine hydrochloride.

MAIN OUTCOMES AND MEASURES

Incident T2D during follow-up. Intention-to-treat effects were estimated using Cox proportional hazards regression models, adjusting for confounding through propensity score stratification. As-treated effects to account for continuous treatment were estimated using inverse probability weighting and marginal structural models.

RESULTS

A total of 1 582 914 patients were included in the analysis (58.3% female; mean [SD] age, 15.1 [2.3] years). The SSRI-treated group included 316 178 patients in the MAX database (publicly insured; mean [SD] age, 14.7 [2.1] years; 62.2% female) and 211 460 in the MarketScan database (privately insured; mean [SD] age, 15.8 [2.3] years; 63.9% female) with at least 2 SSRI prescriptions filled, followed up for a mean (SD) of 2.3 (2.0) and 2.2 (1.9) years, respectively. In publicly insured patients, initiation of SSRI treatment was associated with a 13% increased hazard of T2DM (intention-to-treat adjusted hazard ratio [aHR], 1.13; 95% CI, 1.04-1.22) compared with untreated patients. The association strengthened for continuous SSRI treatment (as-treated aHR, 1.33; 95% CI, 1.21-1.47), corresponding to 6.6 (95% CI, 4.2-10.4) additional cases of T2D per 10 000 patients treated for at least 2 years. Adjusted HRs were lower in privately insured patients (intention-to-treat aHR, 1.01 [95% CI, 0.84-1.23]; as-treated aHR, 1.10 [95% CI, 0.88-1.36]). Findings were similar when comparing SSRI treatment with psychotherapy (publicly insured as-treated aHR, 1.44 [95% CI, 1.25-1.65]; privately insured as-treated aHR, 1.21 [95% CI, 0.93-1.57]), whereas no increased risk was observed compared with bupropion treatment publicly insured as-treated aHR, 1.01 [95% CI, 0.79-1.29]; privately insured as-treated aHR, 0.87 [95% CI, 0.44-1.70]). For the within-class analysis, no medication had an increased hazard of T2D compared with fluoxetine.

CONCLUSIONS AND RELEVANCE

These findings suggest that children and adolescents initiating SSRI treatment may be at a small increased risk of developing T2D, particularly publicly insured patients. The magnitude of association was more modest than previously reported, and the absolute risk was small. The potential small risk should be viewed in relation to the efficacy of SSRIs for its major indications in young patients.

Severe Potential Drug-Drug Interactions and the Increased Length of Stay of Children in Intensive Care Unit

Children are exposed to drug-drug interactions (DDI) risks due to their organism’s complexity and the need for several medicines prescriptions in pediatric intensive care units (PICU). This study aimed to assess the prevalence of potential DDIs in a Brazilian PICU. We carried out a cross-sectional study at a pediatric teaching hospital from Rio de Janeiro (Brazil) over one year. Potential DDIs (pDDIs) between prescribed medicines for hospitalized children in PICU (n = 143) were analyzed according to severity using Micromedex^®. Sex, age group, number of drugs prescribed, vasoactive amines use (a proxy of clinical complexity), and the PICU length of stay were summarized using descriptive statistics. Association between the PICU length stay, and variables sex, age, clinical condition complexity, number of drugs prescribed, and severity of pDDI were examined by univariate and multiple linear regression. Seventy percent of patients aged three days to 14 years old were exposed at least one potential DDIs during PICU stay. Two hundred eighty-four different types of pDDIs were identified, occurring 1,123 times. Nervous system drugs were implicated in 55% of the interactions, and fentanyl (10%) was most involving in pDDIs. Most pDDIs were classified as higher severity (56.2%), with reasonable documentation (64.6%) and unspecified onset time (63.8%). Worse clinical condition, ten or more drugs prescribed, and most severe pDDIs were associated with a longer PICU length of stay. Multiple linear regression analysis showed an increase of 9.83 days (95% confidence interval: 3.61–16.05; p = 0.002) in the PICU length of stay in children with major or contraindicated pDDIs. The results of this research may support the monitoring and prevention of pDDIs related to adverse events in children in intensive care and the design and conduction of new studies.

Validity of administrative claims-based algorithms for ventricular arrhythmia and cardiac arrest in the pediatric population

PURPOSE

Identify administrative claims-based algorithms for capturing out-of-hospital ventricular arrhythmias (VA) and cardiac arrests (CA) due to cardiac causes in the pediatric population with high positive-predictive value (PPV).

METHODS

Within a single pediatric center, a retrospective cohort of patients hospitalized or seen in the emergency room for VA or CA were identified from the electronic health records. Eligible encounters were blindly reviewed and linked to administrative data, including ICD-9/ICD-10 codes. Test characteristics, including PPV, for different diagnostic and procedure codes were generated using a 50% training sample. The gold standard was definite or suspected out-of-hospital VA or CA due to cardiac cause verified based on clinical criteria. Algorithms with the highest PPV were then applied to a 50% validation sample to validate performance.

RESULTS

From 2004-2017, 598 encounters met eligibility criteria. 174 (29%) had an outcome of interest, with remainder being an inpatient event or CA due to other cause. Within the training sample (n = 263), VA codes in primary position had a PPV 94% (95%CI 81%-99%) with low sensitivity (44%, 95%CI 33%-56%). CA codes in any position or VA codes in nonprimary positions had low PPV (18%-19%, 31% respectively). Applying the top three performing algorithms to the validation sample (n = 252) yielded similar PPV values.

CONCLUSIONS

Contrary to adults, algorithms including a CA code do not perform well for identifying out-of-hospital VA and CA due to cardiac cause in the pediatric populations. Researchers should be aware of the potential implications for future pediatric drug safety studies for these outcomes.

Real-World Evidence to Assess Medication Safety or Effectiveness in Children: Systematic Review

Background

The promise of real-world evidence (RWE) is especially relevant to pediatrics, where medicines prescribed for children are often used without evidence derived from randomized clinical trials.

Objectives

The aim of this systematic review was to describe the state of RWE in pediatrics by identifying observational studies published during 2016 that used RWE to assess medication safety or effectiveness in children.

Methods

An electronic search of PubMed was combined with an extended search of references within systematic reviews and expert suggestions. Studies were included if they reported on an infant or child under 18 years with exposure to medications; assessed safety or effectiveness; specified a comparison or control group, and were published in English in 2016. Data extraction was conducted by one team member using a standardized form and reviewed by a second team member. Study quality was assessed using the GRACE checklist for rating the quality of observational studies.

Results

After removing duplicates, 915 citations were screened and 29 studies met the eligibility criteria. Most of the eligible studies relied on primary data collection or chart review at a single institution and did not use the growing number of administrative or electronic health record databases available. One-quarter of the studies did not use well-established statistical methods to control for confounders. No single disease group or medication predominated, and age groups ranged from infants to adolescents.

Conclusions

A small body of observational studies published in 2016 were categorized by the study team as using real-world data to assess medication safety or effectiveness in children. Studies varied in age groups, diseases or conditions, and methods, and may not have fully met the FDA definition of RWE. Our review indicates that the use of RWE is not fully developed in pediatrics, and suggests an opportunity to further develop capabilities and more fully leverage administrative and electronic health record databases to study medication safety and effectiveness in children. Our systematic review appears generalizable to pediatrics broadly, and documents that the high level of activity in RWE in general has had less of an impact on pediatrics.

Electronic supplementary material

The online version of this article (10.1007/s40801-020-00182-y) contains supplementary material, which is available to authorized users.

Big Data in the Assessment of Pediatric Medication Safety

Big data (BD) in pediatric medication safety research provides many opportunities to improve the safety and health of children. The number of pediatric medication and device trials has increased in part because of the past 20 years of US legislation requiring and incentivizing study of the effects of medical products in children (Food and Drug Administration Modernization Act of 1997, Pediatric Rule in 1998, Best Pharmaceuticals for Children Act of 2002, and Pediatric Research Equity Act of 2003). There are some limitations of traditional approaches to studying medication safety in children. Randomized clinical trials within the regulatory context may not enroll patients who are representative of the general pediatric population, provide the power to detect rare safety signals, or provide long-term safety data. BD sources may have these capabilities. In recent years, medical records have become digitized, and cell phones and personal devices have proliferated. In this process, the field of biomedical science has progressively used BD from those records coupled with other data sources, both digital and traditional. Additionally, large distributed databases that include pediatric-specific outcome variables are available. A workshop entitled "Advancing the Development of Pediatric Therapeutics: Application of 'Big Data' to Pediatric Safety Studies" held September 18 to 19, 2017, in Silver Spring, Maryland, formed the basis of many of the ideas outlined in this article, which are intended to identify key examples, critical issues, and future directions in this early phase of an anticipated dramatic change in the availability and use of BD.

Pharmaco-epidemiological research on herbal medicinal products in the paediatric population: data from the PhytoVIS study

In paediatrics, clinical study data are limited, especially on herbal medicinal products. To address this gap, 2063 datasets from the paediatric population were evaluated in the PhytoVIS data base. By screening for paediatric data, information on indication, gender, treatment, co-medication and tolerability were evaluated. The majority of patients was treated because of common cold, fever, digestive complaints, skin diseases, sleep disturbances and anxiety. The perceived effect of the therapy was rated in 84% of the patients as very good or good without adverse events. The data shed light on a still neglected field of phyto-pharmacotherapy by giving information on the use of herbal medicines in an unselected cohort of paediatric patients. The results confirm the good clinical effects and safety of herbal medicinal products in this patient population and show that they are widely used in Germany.What is Known:• In Germany, about 85% of children receive one or more herbal medicinal products per year.• Despite international initiatives to promote clinical research in paediatrics, there are still many gaps of knowledge in the use of drugs in paediatrics.What is New:• The PhytoVIS project evaluated 2063 data sets from the paediatric population using herbal medicinal products.• The majority of patients was treated because of common cold, fever, digestive complaints, skin diseases, sleep disturbances and anxiety, and 84% of the patients rated the therapy as very good or good without adverse events.

Suspected adverse drug reactions reported for Brazilian children: cross-sectional study

OBJECTIVE

To assess spontaneous reports of suspected adverse drug reactions in children aged 0-12 years from the Brazilian Health Regulatory Agency between 2008 and 2013.

METHODS

A cross-sectional study on suspected adverse drug reactions reports related to medicines and health products in children was carried out for a six-year period (2008-2013). Year of report, origin of report by Brazilian state, gender, age, suspected drug, adverse reaction description and seriousness were included in the analysis. The data obtained was compared to the number of pediatric beds in health services and to global data from the VigiBase (World Health Organization).

RESULTS

A total of 3330 adverse drug reactions were reported in children in Brazil in the investigated period (54% were in boys). About 28% of suspected adverse drug reactions reports involved 0 to 1-year-old children. Almost 40% of reports came from the Southeast region. Approximately 60% were classified as serious events. There was death in 75 cases. Nearly 30% of deaths involved off-label use; 3875 medicines (465 active substances) were considered suspected drugs. Anti-infective (vancomycin, ceftriaxone, oxacillin, and amphotericin), nervous system (metamizole) and alimentary tract and metabolism medicines were more frequent in reports.

CONCLUSIONS

The distribution of suspected adverse drug reactions reports by sex and age group corresponded to the profile of children hospitalized in Brazil. Data about seriousness and medicines reported may be useful to encourage regulatory actions and improve the safe use of medicines in children.

Identifying the "Blip on the Radar Screen": Leveraging Big Data in Defining Drug Safety and Efficacy in Pediatric Practice

The immense amount of electronic health data (pharmacy and administrative claims, electronic health records, and clinical registries) that is being generated every day in the care of patients has the potential to be leveraged for improving clinical decisions at the point of care, uncovering or validating drug efficacy and drug safety. The potential use of big data for improving safe and effective use of medications is especially important in children because of their low drug exposure relative to adults. Electronic health data is collected primarily for clinical or billing purposes and not for research purposes. The major steps involved in data acquisition, extraction, aggregation, analysis, modeling, and interpretation are discussed. It is important to understand the limitation of big data and utilize appropriate study design and statistical methods. Possible applications are presented along with specific examples of how big data has been used in drug research to find that blip on the radar screen that may give an efficacy or safety signal that can lead to further investigation.

Evaluating Safety Reporting in Paediatric Antibiotic Trials, 2000-2016: A Systematic Review and Meta-Analysis

BACKGROUND

There are very few options to treat multidrug-resistant bacterial infections in children. A major barrier is the duration and complexity of regulatory trials of new antibiotics. Extrapolation of safety data from adult trials could facilitate drug development for children.

OBJECTIVE

We performed a systematic review on the safety of antibiotic clinical trials (CTs) in children (0-18 years) to evaluate the overall quality of safety trials conducted in children and to determine if age-specific adverse events (AEs) could be identified for specific antibiotic classes.

DATA SOURCES

We searched the MEDLINE, Cochrane CENTRAL, and ClinicalTrials.gov electronic databases for trials conducted between 2000 and 2016.

STUDY SELECTION

All trials in which safety was declared a primary or secondary endpoint were included. Exclusion criteria were (1) topical or inhalational route of administration; (2) non-infectious conditions; (3) administration for prophylaxis rather than treatment; (4) selected population (i.e. cystic fibrosis, malignancies, HIV and tuberculosis); and (5) design other than randomized controlled trials. Trials reporting data on both adults and children were included only if paediatric results were reported separately.

DATA EXTRACTION AND SYNTHESIS

Two authors independently extracted the data. To assess the quality of published trials, the Extension for harms for Consolidated Standards of Reporting Trials (CONSORT) Statement 2004 was used.

MAIN OUTCOME AND MEASURE

In order to quantitatively assess the rate of developing AEs by drug class, the numbers of overall and body-system-specific AEs were collected for each study arm, and then calculated per single drug class as median and interquartile range (IQR) of the proportions across CTs. The AEs most frequently reported were compared in the meta-analysis by selecting the CTs on the most represented drug classes.

RESULTS

Eighty-three CTs were included, accounting for 27,693 children. Overall, 69.7% of CONSORT items were fully reported. The median proportion of children with any AE was 22.5%, but did not exceed 8% in any single body system. Serious drug-related AEs and drug-related discontinuations were very rare (median 0.3 and 0.9%, respectively). Limitations included the inability to stratify by age group, particularly neonates.

CONCLUSIONS AND RELEVANCE

Overall, AEs in paediatric antibiotic CTs were predictable and class-specific, and no unexpected (age-specific) side effects were identified. Smaller, open-label, dose-finding, high-quality, single-arm pharmacokinetic trials seem potentially sufficient for certain common antibiotic classes, extrapolating well-established safety profiles determined from large adult efficacy trials. This approach could reduce duration and enhance subsequent registration of urgently needed new antibiotics. This will need to be combined with enhanced methods of pharmacovigilance for monitoring of emerging AEs in routine clinical practice.

Pharmacoepidemiological research for the development and evaluation of drugs in pediatrics

New regulations have come into force in Europe and the US establishing the pediatric development as an integral part of the early development of medicinal products. Parallel to the advances in pediatric clinical research, it became obvious that all available sources and research tools to gather valuable information for the safe and efficacious prescription of medicines in children should be used. Real-life, pharmacoepidemiological studies provide information that contribute to the better knowledge of drug utilization, effects and safety in the pediatric population and thereby, a better prescribing in children. In this paper, we suggest some possible applications, provide examples of impact of pharmacoepidemiological and pharmacovigilance studies and expose future perspectives in pediatric pharmacoepidemiology.

Electronic health record (EHR) based postmarketing surveillance of adverse events associated with pediatric off-label medication use: A case study of short-acting beta-2 agonists and arrhythmias

PURPOSE

Use electronic health record (EHR) data to (1) estimate the risk of arrhythmia associated with inhaled short-acting beta-2 agonists (SABA) in pediatric patients and (2) determine whether risk varied by on-label versus off-label prescribing.

METHODS

Retrospective cohort study of 335 041 children ≤18 years using EHR primary care data from 2 pediatric health systems (2011-2013). A series of monthly pseudotrials were created, using propensity score methodology to balance baseline characteristics between SABA-exposed (identified by prescription) and SABA-unexposed children. Association between SABA and subsequent arrhythmia for each health system was estimated through pooled logistic regression with separate estimates for children initiating under and over 4 years old (off-label and on-label, respectively).

RESULTS

Eleven percent of the cohort received a SABA prescription, 57% occurred under the age of 4 years (off-label). During the follow-up period, there were 283 first arrhythmia events, most commonly atrial tachyarrhythmias and premature ventricular/atrial contractions. In 1 health system, adjusted risk for arrhythmia was increased among exposed children (OR 1.89, 95% CI 1.31-2.73) without evidence of interaction between label status and risk. The absolute adjusted rate difference was 3.6/10 000 person-years of SABA exposure. The association between SABA exposure and arrhythmias was less strong in the second system (OR 1.26, 95% CI 0.30-5.33).

CONCLUSION

Using EHR data, we could estimate the risk of a rare event associated with medication use and determine difference in risk related to on-label versus off-label status. These findings support the value of EHR-based data for postmarketing drug studies in the pediatric population.

Pharmacoepidemiology in pediatrics: Needs, challenges and future directions for research

Despite international initiatives to promote clinical research in pediatrics, there are still many gaps of knowledge in the use of drugs to treat this specific population. When important information cannot be derived only from clinical trials, use of available observational research tools is required. In this paper, we provide an overview of the particular interest of pharmacoepidemiological research into the evaluation of drug effects in children and adolescents. We also sought to underline the unique challenges and specific needs regarding this research. Implementation of innovative methodologies and expansion of database networks to perform necessary studies could further improve performances of observational research.

Off-label prescribing for children with chronic diseases in Nigeria; findings and implications

BACKGROUND

Prescribing medicines in an off-label manner for children with chronic conditions is sparsely documented, even more so among developing countries. This needs addressing. The objective of this research was to investigate the extent of off-label prescribing among children with epilepsy, asthma, and sickle cell anaemia in Nigeria.

METHODS

Prescriptions for children ≤16 years documented in their case files that attended paediatric clinics in Lagos, Nigeria, for these three conditions between January and October 2015, were reviewed retrospectively to extract data on the medicines prescribed. British National Formulary for children and American Hospital Formulary Service Drug information were used as references.

RESULTS

477 patients received 1746 prescriptions. Off-label prescriptions were seen in 7.7% of prescriptions, related to dose (93; 68.9%), indication (22; 16.3%), and age (20; 14.8%). Nervous system (525; 30.1%) and anti-infective (441; 25.2%) medicines were the most prescribed but only 9.5% and 8.2% of the respective prescriptions were off-label. Children with epilepsy received the most number (94; 69.6%) of off-label prescriptions. The three chronic conditions did not associate significantly with the category of off-label medicine prescribed (p = 0.925).

CONCLUSION

Off-label prescribing for children with epilepsy, asthma and sickle cell anaemia occurs. Encouragingly, the overall rate appears low in Nigeria.

Pharmacoepidemiological safety studies in children: a systematic review

Purpose

In order to identify challenges in pediatric pharmacoepidemiological safety studies, we assessed the characteristics of such (published) studies.

Methods

Relevant articles from inception to 2013 were retrieved from Embase and Medline. We sequentially screened titles, abstracts and full texts with independent validation. We systematically collected data regarding general information, study methods and results.

Results

Out of 4825 unique articles, 268 full texts (5.6%) were retained; 147 (54.9%) pertained to drugs rather than vaccines. Considering the 268 studies, 202 (75.4%) concerned children and adolescents (2 to 11 years) and 14 (5.3%) included preterm newborns. Most studies originated from North America (154 [57.5%]) or Europe (92 [34.3%]). Only 47 studies (17.5%) were privately funded. The majority (174 [64.9%]) were cohort studies. Out of 268 studies, 196 (73.1%) collected data retrospectively; paper medical charts were the most common data source for the exposures (85 [31.7%]) and outcomes (122 [45.5%]). Only 3 (2.0%) drug‐only studies investigated rarely used drugs. Considering all 268 studies, only 27 (10.1%) reported sample size or power calculation. Most (75 [51.0%]) drug‐only studies corrected confounding by multivariate modeling unlike stratification in 66 (55.9%) vaccine‐only studies. Considering 75 child‐only studies without any statistically significant result, 41 (54.7%) did not discuss lack of power.

Conclusions

Although the field of pediatric pharmacoepidemiology is steadily developing evaluation seldom includes neonates, is mainly focused on few drug classes and safety outcomes and concerns mainly drug use in developed countries. Small study size is a specific challenge in pediatrics. Reporting should be improved. © 2016 The Authors. Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.