Avoiding adverse drug reactions in children - development of the Liverpool Adverse Drug Reaction Avoidability Assessment Tool

摘要

Adverse drug reactions (ADRs) are common in children. They contribute significantly to patient morbidity, mortality and hospitalisation costs. 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 or designed for use in paediatrics. The aim of this thesis was to develop and test a new avoidability assessment tool that is suitable for use in paediatrics. The stimulus for this work was difficulty using other tools including the one developed by Hallas et al. (1990). Ideally the new tool should also be applicable and generalisable to a variety of other settings. A secondary objective was to identify potential strategies for clinical practice that might reduce the incidence of ADRs. 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. The development of the LAAT was a multistep process which involved a multidisciplinary team (MDT). Individual and group assessments were conducted and qualitative and quantitative analyses of the assessments were carried out. The LAAT has undergone validity and reliability testing for groups and individuals. The newly validated LAAT was used to assess 249 ADR case reports from a prospective paediatric admissions study by one individual and compared to existing avoidability assessments conducted using the Hallas scale. Assessment of these ADR case reports using the LAAT found that 19.3% were either possibly or definitely avoidable. This was similar to results using the Hallas scale where 22% of the reactions were either possibly or definitely avoidable. Overall percentage exact agreement (%EA) between LAAT and the Hallas scale was 90%; when subcategorised into oncology and non-oncology cases the %EA was found to be 94.2 and 86% respectively. The kappa score between LAAT and Hallas scale assessments was 0.71 (95% CI 0.60 - 0.82) for all cases, 0.54 (95% CI 0.40 - 0.68) for the oncology cases and 0.73 (95% CI 0.58 - 0.88) for the non-oncology cases. The most common avoidability theme detected in this study was inappropriate or suboptimal prescribing. Assessing the avoidability of ADRs is a complex process which requires taking into account a number of factors. Strategies to avoid ADRs can be applied at different levels including: patient, ward, departmental institutional, professional, and national. A common theme that emerged from this work was the lack of available guidelines that could be used to assess whether ADRs were avoidable. Where guidelines were available few contained information about ADRs or their prevention. The majority of clinicians relied on their experience and tacit knowledge rather than on guidelines. Some of the ADRs categorised as either possibly or definitely avoidable may have been avoidable with improved prescribing, more frequent monitoring or improved education of patients and/or parents. Other possible prevention strategies include creating an awareness of ADRs in general and their prevention throughout a clinician’s training. Improved communication and documentation in patient records is a simple but effective method of ADR reduction. In summary, we have designed a novel avoidability assessment tool, developed by a multidisciplinary team, and have shown that the new tool is comparable to an existing avoidability tool, can be used by individuals and most importantly is suitable for use in paediatrics or other areas where clinical conditions extend beyond the expertise of individuals. The LAAT refers to guidelines and patient history rather than to abstract concepts such as ‘present-day knowledge of good medical practice’ and ‘effort exceeding the obligatory demands’ as per Hallas. Further work to identify potentially avoidable ADRs and strategies to prevent them is needed.