Liverpool Adverse Drug Reaction Avoidability Assessment Tool (LAAT)

A novel tool developed to assess the avoidability of adverse drug reactions in children.

Adverse drug reactions (ADRs) are common in children. They contribute significantly to patient morbidity, mortality and hospitalisation costs. The incidence of ADRs in hospitalised children has been reported as ranging from 0.6-16.8% among studies. There is limited data on the avoidability of ADRs in children and wide variation in avoidability rates has been reported.

There is currently no standardised method for determining avoidability and many of the established tools are not suitable for use in paediatrics. The need for developing a new tool was identified during the Adverse Drug Reactions in Children (ADRIC) programme following difficulties using other avoidability tools.


Although the LAAT was designed for use in paediatrics ideally, it should also be generalisable to a variety of different patient groups, reproducible and easy to use. A secondary objective was to identify potential strategies for clinical practice that might reduce the incidence of ADRs.


A modified version of the Hallas Scale was used as the starting point for the development of the LAAT. The initial draft of the LAAT was developed via a consensus approach.

Phase one consisted of three parts (defining, modifying and refining the tool) involving 2 multidisciplinary teams each comprising a nurse, paediatrician and pharmacist.

Phase two involved the independent assessment of 50 ADR cases from the ADRIC paediatric inpatient study by six reviewers.

Phase 3 compared assessments with the new tool for individuals and groups in comparison to the ‘gold standard’ (avoidability outcome set by a panel of senior investigators: clinical pharmacologist, paediatrician and pharmacist) to test the hypothesis that group assessments are superior to individual avoidability assessments.

In summary, we have designed a novel tool which was shown to be comparable to an existing avoidability tool. The LAAT can be used by individuals and most importantly is suitable for use in paediatrics.


To date the LAAT has only been used in a research setting. The LAAT is practicable and has shown that it can be used effectively by individuals or groups. It was developed as part of the ADRIC programme and could be used in similar studies to determine the rate of avoidable ADRs.

Although the tool was developed predominantly as a research tool, we are now looking at the possible adaptation for clinical practice. Three key themes for avoidability have been established through a review of existing literature. These are: inappropriate or suboptimal prescribing, inadequate monitoring and inadequate patient or parent education.

Suggestions for Further Implementation

The LAAT could potentially be used for organisational change. Inviting members of the drug and therapeutic committee and senior clinicians with experience in the regulatory field to assess the avoidability of a selection of ADR case reports using the LAAT, may help identify prevention strategies.

Assessing the avoidability of ADRs is a complex process which requires consideration of a number of factors. Identifying ADRs which might be avoidable can help us to improve practice which can help to reduce the number of children who have an ADR. There are issues regarding the terminology used in the area of pharmacovigilance and this can make the comparison of studies difficult, achieving consensus on terminology in this area would be a big step forward.

A clear definition of adverse drug reactions is needed so that data on ADRs can be consistently reported and reliably interpreted.

The LAAT has undergone a rigorous testing process. Extensive review and evaluation as part of an NIHR research study.

The next step would be external validation. Work on the development process of the LAAT has been presented at various meetings including: European Academy of Paediatric Societies, European Society for Paediatric Research and the Neonatal and Paediatric Pharmacists Group.

The development of the tool has been published in PLOS ONE.


Project Lead: Dr Louise Bracken, Research Pharmacist

Organisation: Alder Hey Children’s NHS Foundation Trust

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