Adverse drug reaction classification by health professionals: appropriate discrimination between allergy and intolerance?

Jie Shen Fok,Gillian E Caughey,William B Smith,Sepehr Shakib

doi:10.1186/s13601-019-0259-6

Abstract

BackgroundThe correct classification of an adverse drug reaction (ADR) as allergy (immunological) or intolerance (non-immunological) has important clinical implications. The aim of this study was to examine the ability of health professionals to discriminate between allergy and intolerance, classify the severity of the ADR and degree of contraindication.MethodsHealth professionals were presented ten ‘real-life’ ADR scenarios using an online questionnaire and asked to: categorise the reaction as allergy or intolerance, rate the severity of the reaction and judge the level of contraindication of the causative drug. The number and proportion of responses were calculated for each of the cases presented and associations between classification of reaction type, severity and level of contraindication were examined.ResultsA total of 394 responses were received. Overall 59.0% (SD 28.9) correctly categorised the cases, 60.8% (SD 16.8) classified the severity correct, and less than half (44.7%, SD 28.6) correctly identified the level of contraindication. The proportion of health professionals correctly answering the type, severity and level of contraindication for the allergy case was significantly higher (p < 0.0001) by comparison to the intolerance cases (type: 56.6% ± 33.1; severity: 57.3 ± 11.9; level of contraindication: 38.5 ± 19.9).ConclusionsHealth professionals have suboptimal understanding of classification of ADRs. Strategies are required to strictly avoid re-exposure of patients to drugs which carry an increased risk of inducing a dangerous reaction, whilst minimising the avoidance of drugs which are of minimal risk or allowing the use of low-risk drugs where the benefits may be significant.

Highlights

In Australia, medication-related incidents are estimated to account for 2–3% of all hospital admissions [1]
Medical practitioners included a range of specialties with varying levels of experience from interns (27.5%), basic and advanced internal medicine trainees (56.3%), to clinical specialists (16.2%) from a range of disciplines including immunology (6.9%), clinical pharmacology (4.4%) and other specialties (88.7%)
For the second allergy case presented, of a hypersensitivity reaction to carbamazepine manifesting in Stevens– Johnson syndrome (SJS), overall 76% of health professionals correctly identified this as allergy

Summary

Introduction

In Australia, medication-related incidents are estimated to account for 2–3% of all hospital admissions [1]. Using ICD-10 codes, adverse drug reactions (ADRs) account for at least 1.3% of all admissions, whilst an ADR occurs on admission or during a hospital stay in 2.7–3.3% of patients [2, 3]. The correct classification of an ADR as allergy or intolerance has important clinical implications, especially with regard to future exposure or avoidance of the drug. Allergy is commonly assumed to be more serious, but intolerance may be life-threatening, reaction severity might be a more important parameter than mechanistic classification. The correct classification of an adverse drug reaction (ADR) as allergy (immunological) or intolerance (non-immunological) has important clinical implications. The aim of this study was to examine the ability of health professionals to discriminate between allergy and intolerance, classify the severity of the ADR and degree of contraindication

Objectives

Methods

Results

Conclusion