Adverse drug reactions causing admission to a paediatric hospital

Clinical coding of prospectively identified paediatric adverse drug reactions--a retrospective review of patient records

BACKGROUND

National Health Service (NHS) hospitals in the UK use a system of coding for patient episodes. The coding system used is the International Classification of Disease (ICD-10). There are ICD-10 codes which may be associated with adverse drug reactions (ADRs) and there is a possibility of using these codes for ADR surveillance. This study aimed to determine whether ADRs prospectively identified in children admitted to a paediatric hospital were coded appropriately using ICD-10.

METHODS

The electronic admission abstract for each patient with at least one ADR was reviewed. A record was made of whether the ADR(s) had been coded using ICD-10.

RESULTS

Of 241 ADRs, 76 (31.5%) were coded using at least one ICD-10 ADR code. Of the oncology ADRs, 70/115 (61%) were coded using an ICD-10 ADR code compared with 6/126 (4.8%) non-oncology ADRs (difference in proportions 56%, 95% CI 46.2% to 65.8%; p < 0.001).

CONCLUSIONS

The majority of ADRs detected in a prospective study at a paediatric centre would not have been identified if the study had relied on ICD-10 codes as a single means of detection. Data derived from administrative healthcare databases are not reliable for identifying ADRs by themselves, but may complement other methods of detection.

Adverse drug reactions and off-label and unlicensed medicines in children: a prospective cohort study of unplanned admissions to a paediatric hospital

AIMS

To examine the impact of off-label and unlicensed (OLUL) prescribing on adverse drug reactions (ADRs) causing unplanned admissions to a paediatric hospital.

METHODS

Prescription data from a 12 month prospective cohort study of ADRs detected in children admitted to a paediatric hospital were scrutinized. The relative risk for off-label and unlicensed medicines being implicated in an ADR was calculated. Logistic regression analyses were carried out with exposure to off-label and unlicensed medicines and number of off-label and unlicensed medicines administered as predictor variables.

RESULTS

Off-label and unlicensed medicines were more likely to be implicated in an ADR than authorized medicines (relative risk 1.67, 95% CI 1.38, 2.02, P < 0.001). There was a 25% increase in ADR risk (95% CI 1.16, 1.35, P < 0.001) with each additional authorized medicine and 23% (95% CI 1.10, 1.36, P < 0.001) with each additional off-label or unlicensed medicine. Logistic regression analysis focusing on non-oncology patients demonstrated that the number of authorized medicines (odds ratio 1.33, 95% CI 1.23, 1.44, P < 0.001), but not the number of off-label and unlicensed medicine courses, was a predictor of ADR risk.

CONCLUSIONS

In a heterogeneous population of children admitted to a secondary/tertiary hospital, off-label and unlicensed medicines are more likely to be implicated in an ADR than authorized medicines. This was largely driven by ADRs related to drugs used in oncological practice, where the usage of off-label or unlicensed medicines was associated with a higher ADR risk than in non-oncological areas.

Use of administrative hospital database to identify adverse drug reactions in a Pediatric University Hospital

PURPOSE

The aim of the study was to detect adverse drug reactions (ADRs) in pediatric inpatients using the medical administrative database "Programme de Médicalisation des Systèmes d'Information" (PMSI) and to compare these cases ADRs with those spontaneously reported to a regional PharmacoVigilance (PV) Centre.

METHODS

The study was conducted from January 2008 to December 2011 in the Children University Hospital of Toulouse (Midi-Pyrénées, South-west France). From PMSI database, all discharge summaries including selected ICD-10 codes (10th International Classification of Diseases) were analyzed. All ADRs spontaneously reported by the Children Hospital of Toulouse and registered in the French PV Database (FPVDB) were included. The capture-recapture method was applied to estimate the incidence of ADRs.

RESULTS

During the study period, we identified 60 reports from the PMSI database and 200 from the FPVDB. The rate of "serious" ADRs was higher in PMSI reports (74.6 % vs 38.9 %, p < 0.0001). The most frequent ADRs reported were musculoskeletal (12.4 %) and central (11.3 %) ADRs in PMSI database versus cutaneous (22.4 %) and general (17.5 %) ADRs in FPVDB. The most frequently suspected drugs were antineoplastic drugs (31.1 %) in PMSI database versus anti-infectives (38.2 %) in FPVDB. The estimated number of ADRs was 717 [95 % confidence interval (CI) 513, 921], and the incidence of ADRs among admissions was 0.6 % (95 % CI 0.4, 0.8).

CONCLUSIONS

Use of PMSI database improves from around 30 % detection of ADRs in children. In comparison with classical pharmacovigilance database, it also allows to detect different ADRs and drugs, thus enhancing safe medicine use for pediatric patients.

Dexamethasone and haemorrhage risk in paediatric tonsillectomy: a systematic review and meta-analysis

Summary In children undergoing tonsillectomy, dexamethasone is recommended to reduce the risk of postoperative nausea and vomiting while non-steroidal anti-inflammatory drugs (NSAIDs) are used for pain relief. We aimed to determine whether children who receive dexamethasone or dexamethasone with NSAID are more likely to experience haemorrhage post-tonsillectomy. Randomized and non-randomized studies in which children undergoing tonsillectomy received dexamethasone or dexamethasone and NSAID were sought within bibliographic databases and selected tertiary sources. The risk of bias assessment and evaluation of haemorrhage rate data collection and reporting were assessed using the Cochrane Risk of Bias Tool and McHarm tool. Synthesis methods comprised pooled estimate of the effect of dexamethasone on the risk of haemorrhage rate using the Peto odds ratio (OR) method. The pooled estimate for haemorrhage rate in children who received dexamethasone was 6.2%, OR 1.41 (95% confidence interval 0.89-2.25, P=0.15). There was risk of bias and inconsistent data collection and reporting rates of haemorrhage in many of the included studies. Clinical heterogeneity was observed between studies. The pooled analysis did not demonstrate a statistically significant increase in the risk of post-tonsillectomy haemorrhage with dexamethasone with/without NSAID use in children. However, the majority of the included studies were not designed to investigate this endpoint, and thus large studies which are specifically designed to collect data on haemorrhage rate are needed.

Pediatric perspective on pharmacogenomics

The advances in high-throughput genomic technologies have improved the understanding of disease pathophysiology and have allowed a better characterization of drug response and toxicity based on individual genetic make up. Pharmacogenomics is being recognized as a valid approach used to identify patients who are more likely to respond to medication, or those in whom there is a high probability of developing severe adverse drug reactions. An increasing number of pharmacogenomic studies are being published, most include only adults. A few studies have shown the impact of pharmacogenomics in pediatrics, highlighting a key difference between children and adults, which is the contribution of developmental changes to therapeutic responses across different age groups. This review focuses on pharmacogenomic research in pediatrics, providing examples from common pediatric conditions and emphasizing their developmental context.

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.

Personalized pharmacogenomics: predicting efficacy and adverse drug reactions

Drug response varies between individuals owing to disease heterogeneity, environmental factors, and genetic factors. Genetic factors can affect both the pharmacokinetics and pharmacodynamics of a drug, leading to changes in local and systemic drug exposure and/or changes in the function of the drug target, altering drug response. Several pharmacogenetic biomarkers are already utilized in clinical practice and have been shown to improve clinical outcomes. However, a large number of other biomarkers have never made it beyond the discovery stage. Concerted effort is needed to improve the translation of pharmacogenetic biomarkers into clinical practice, and this will involve the use of standardized phenotyping and genotyping strategies, collaborative work, multidisciplinary approaches to identifying and replicating associations, and cooperation with industry to facilitate translation and commercialization. Acceptance of these approaches by clinicians, regulators, patients, and the public will be important in determining future success.

Adverse drug reactions causing hospital admissions in childhood: a prospective, observational, single-centre study

Adverse drug reactions (ADRs) are common problems in both paediatric and adult medicine. The aim of this study was to prospectively identify the ADRs causing hospital admission of children and identification of the risk factors and involved drugs. The study was performed at the University Hospital in Olomouc, Czech Republic. All patients aged 19 years or under admitted to hospital were included in the study, and all admissions for ADRs were prospectively screened for a period of 9 months. Suspected ADRs were subsequently evaluated in detail, and causality assessment was undertaken to determine whether each suspected reaction was possible, probable or definite. The assessment of ADR causality was performed using the Naranjo algorithm, the Liverpool ADR Causality Assessment Tool and the Edwards and Aronson causality assessment method. During the study period, 2903 admissions were identified; of these, there were 143 admissions of patients with an oncological disease. Sixty-four admissions (2.2%) were caused by an ADR. Anticancer chemotherapy accounted for 35% of the cases, followed by antibiotics (18%), immunosuppressants and vaccines (9% each). The use of different scoring systems does not lead to the differences in the numbers of ADR-diagnosed patient but may result in differences in the determination of the level of certainty. ADRs cause a substantial proportion of children's hospital admissions. The majority of the ADR-diagnosed patient affected the hematopoietic and gastrointestinal systems; the drugs most frequently involved were cytotoxic agents and antibiotics. The most important risk factors identified were female sex and oncological disease.

Cutaneous drug reactions in children: an update

Cutaneous drug reactions account for a large proportion of adverse drug reactions. Cutaneous drug reactions can be very challenging to diagnose. They can mimic many other skin diseases; this is especially evident during childhood, when viral exanthems are commonplace. Also, if a patient is taking numerous medications, establishing causality to a specific drug can be multifaceted and difficult. The purpose of this review is to highlight an approach to the diagnosis of a suspected cutaneous drug reaction in a child. We have classified different types of drug eruptions by morphology: exanthematous, urticarial, pustular, and bullous. Within each of these groups we have divided them into simple, benign, or non-febrile and complex or febrile reactions. We also include a miscellaneous group to ensure a methodical review.

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.

Comparative epidemiology of hospital-acquired adverse drug reactions in adults and children and their impact on cost and hospital stay--a systematic review

PURPOSE

To study and analyze the comparative impact of hospital-acquired adverse drug reactions (ADRs) in adult and pediatric patients in terms of the economic implications, (length of) hospital stay, and salient features in relation to the incidence rate, severity, morbidity, mortality, and preventability of the ADRs.

METHODS

A systematic search to identify and retrieve relevant articles/studies in the PubMed, Medline, Scopus, MEDPAR, and Cochrane databases and by the Google search engine was performed for the study period 2000 to April 2013. In total, 51 studies were identified on patients hospitalized for ADRs, and these were included in the study. The incidence rate of ADRs, their severity, mortality, morbidity, preventability, cost, and association with extended hospital stay due to ADRs were extracted and scrutinized.

RESULTS

Hospital-acquired ADRs are more widely studied in adults than in children, and the incidence rate is higher in the former. However, a wide variation in the incidence rate worldwide is observed in both groups. Irrespective of the ages of patients, ADRs are among the most frequent causes of morbidity and mortality. Interestingly, preventable ADRs are more frequently observed in patients at the younger and older ends of the age spectrum. Hospital-acquired ADRs place an immense economic burden on healthcare systems, with the overall cost for a hospitalized patient with an ADR reported to be $2,401 per patient, which is equivalent to a 19.86 % additional increase in the total cost of care and an increase in average length of hospital stay of 8.25 %.

CONCLUSION

Based on the findings of this review, we suggest that excellent assertive measures of pharmacovigilance with the aim to diminish the incidence rate of hospital-acquired ADRs and support the development of interventions are needed to promote vital facets of drug safety with an overall objective to avert potential ADRs.