Allergic reactions to prescribed drugs 2019 to 2023 (FOI)

​Request

​A

Please provide the annual breakdown of instances of any prescription that resulted in an allergic response over the past five years. 

B

Please conifrm the number of hospitalisations following an allergic reaction due to drugs or significant drug interactions over the past five years, broken down by year. 

Response

A

Information is not held on medications prescribed and dispensed in the community that result in adverse reaction or allergic response where this does not require admission to hospital. Therefore, Article 3 of the Freedom of Information (Jersey) Law 2011 applies.

From the central records and data available, it is not possible to distinguish between recorded instances of a first (or new) allergic response or adverse reaction to a medication, and those for pre-existing drug allergies. It would not necessarily be known that an individual was allergic to a medicine in advance of them receiving it. For adverse reactions and allergic responses to medications prescribed in the hospital setting, it is not uncommon for that to be the first time an individual is exposed to the particular medication.

Medications could be prescribed, but not administered. Clinical pharmacists will look for recorded allergies when reviewing medication charts and prescriptions on the ward. Where an allergy is recorded, the clinical pharmacist or nurses looking after the patient may query prescriptions prior to this being dispensed or administered. 

Even where a patient has a known allergy, it may be that a clinical decision is taken to provide treatment with the medication, for example, where this would be the best option for the patient and the allergic response they have experienced is of a mild nature.

Similarly with drug interactions, in many cases the risks of the interaction are small or they can be managed (for example, by adjusting doses, times of administration, and so on), so interacting drugs may be legitimately prescribed. Again, this is something which clinical pharmacists look for and review. 

The Electronic Prescribing Medicines Administration (EPMA) system identifies such occasions. 85% of allergy warnings are overridden for clinical reasons, while nearly 60% of interaction warnings are overridden by prescribers. The data from EPMA shows an increasing trend in numbers, however this corresponds with the system rollout over the last four years, rather than an increase in incidence.

The EPMA interaction data is shown in the attached graphic. Only level 3 and 4 interactions are flagged to prescribers. Level 3 is classed as moderate risk, and Level 4 is higher risk. Whilst information will be held in individual medical records prior to the EPMA inception date, this is not available to report from a central record. Therefore, Article 3 of the Freedom of Information (Jersey) Law 2011 applies.

EPMA interaction data.pdf​

B

Annual figures for admissions where allergic reaction or adverse response to a prescribed drug is recorded, or where a drug interaction is documented, are detailed in the table below. Figures include both instances where the issue is documented at presentation to hospital, and where these were experienced in the course of admission.

The data shows the number of distinct admissions per year in which an adverse reaction to a drug, medicament, or biological substance, or a drug interaction is recorded for the past five calendar years (2019 to 2023 inclusive).

Cases meeting the criteria for inclusion have been identified by the diagnosis codes assigned to the episode of care in the Electronic Patient Record. 

Owing to the complexities of diagnostic coding and the National Clinical Coding Standards for adverse effects of drugs or medicaments in therapeutic use, it is not possible to break these instances down to drug reactions and drug interactions. Furthermore, the codes used to identify causative medication(s) do not indicate the severity of the reaction itself.

Adverse effects of drugs (medicaments) may also be described as:

• adverse effect of drug
• allergic reaction
• cumulative toxicity
• hypersensitivity
  
• idiosyncratic reaction
• side effects
• interaction of drugs

Clinical Coding of a person’s admission is carried out after discharge from hospital and figures are derived from reporting by discharge date. As such, those individuals who were admitted prior to 1 January 2019 and discharged after this date will be included. For the same reason, those admitted prior to 31 December 2023 and discharged after this date will not be included in the numbers. Coding is not yet complete for the time period, and consequently, figures may be subject to change as Clinical Coding of cases continues.

​Data Source: Hospital Electronic Records – Clinical Coding Reports (TrakCare CDG4G, Maxims CC5DM)

Article applied

Article 3 - Meaning of “information held by a public authority”

​For the purposes of this Law, information is held by a public authority if –

(a)     it is held by the authority, otherwise than on behalf of another person; or

(b)     it is held by another person on behalf of the authority.​