Patients' knowledge about their drug allergies

The importance of clinical history in the diagnosis of drug hypersensitivity in children

BACKGROUND

In case of suspected hypersensitivity reactions (HRs) to drugs, a challenging area for pediatricians is detecting relevant elements in the parent-reported history, in order to reach a definite diagnosis. We analyzed the concordance between the description of the HR and the medical reports documented at the time of the event. Furthermore, we studied any correlation between clinical history variables and the prediction of true allergy.

METHODS

We retrospectively collected 50 charts of children referred to our Allergy Unit, after a previous access to the Emergency Department. We compared the description of the HR at acute phase to the history told by parents. Type and timing of the HR and culprit drug were classified as "known" or "unknown." The diagnosis was confirmed or excluded at the end of the investigations. Logistic regression analysis was performed to find any significant association.

RESULTS

The type of the HR was known in 74%, the timing in 28%, and the culprit drug in 98%. We showed that having had a severe HR had an increased odds of remembering the timing; being older >6 years and having had an immediate HR had an increased odds of remembering the type; time to diagnostic was lower in patients whose parents remembered the type of HR.

CONCLUSION

Our paper underlines the importance of an accurate anamnesis at the time of the event. Providing the physicians with a standardized Case Report Form could be a useful tool to simplify the diagnostic work-up and minimize mistakes due to lack of memory.

Penicillin Allergy Evaluation and Health Equity: A Call to Action

Allergists have been at the forefront of addressing the burden of unverified penicillin allergy labels. Coordinated national efforts with infectious diseases, antimicrobial stewardship experts, and pharmacy societies to advocate for formal evaluation of patient-reported penicillin allergy have resulted in improvements in delabeling efforts. Given the poorer health outcomes associated with the penicillin allergy label and the potential health benefits that can be gained with delabeling, improving access to penicillin allergy evaluation is of the utmost importance. Health disparities are widely recognized to impact all aspects of health care, and multilevel interventions at the patient, clinician, and systems level are required to ensure equitable care delivery. Structural racism underpins many social determinants of health and is a key driver of racial and ethnic health disparities. In this Rostrum, we use a conceptual framework from the 2015 National Academy of Medicine report Improving Diagnosis in Health Care to explore how inequities are related to the evaluation of penicillin allergy. We use the National Institute on Minority Health and Health Disparities Strategies to Advance Health Disparities to elucidate areas of important study. Building upon existing efforts to address disparities in Allergy/Immunology, we highlight the urgent importance of understanding and eliminating health disparities in penicillin allergy evaluation and delabeling.

Patients have very limited knowledge of their contrast allergies

PURPOSE

To quantify patients' knowledge of their iodinated contrast allergies; and to compare this data to literature estimates of patient knowledge of other medication allergies.

METHODS

Using a key word search of 15,715 patients undergoing a total of 19,043 CT studies over a six-month period, a cohort of 307 adult patients claiming prior allergic reaction to iodinated intravenous contrast was identified. A patient questionnaire with the CT studies inquired about the specifics of their contrast allergy, including the symptoms of their prior allergic reaction; when and where the reaction occurred; and if patients could name the contrast agent to which they claim to be allergic.

RESULTS

In the cohort of 307 patients claiming a prior allergic reaction to iodinated contrast, 86.6% could describe their prior allergic reaction symptoms. Only 36.8% could provide an approximate year of the reaction, with an additional 6.5% claiming that their reactions were remote, for a total of 43.3% providing some information when their reaction occurred. 56.7% provided no information on the year of their reaction. 40.7% named either the facility or the city where the reaction occurred, while 59.3% could not. Only 5 of 307 (1.6%, p < 0.00001) could name the contrast agent to which they believed they were allergic.

CONCLUSION

Other studies have reported inconsistencies, limited documentation, and limited ability to confirm patients' pharmacologic allergies, estimating that patients prior to pharmacist consultation are approximately 60-70% accurate in listing their drug allergies by name. Nevertheless, patients' knowledge of their iodinated contrast allergies is markedly more limited when compared to expected patient knowledge of medication allergies in general.

A UK hospital survey to explore healthcare professional views and attitudes to patients incorrectly labelled as penicillin allergic: an antibiotic stewardship patient safety project

OBJECTIVES

To ascertain the views, beliefs and attitudes of hospital staff to incorrect penicillin allergy records in order to determine healthcare worker motivation for the implementation of a penicillin de-labelling antibiotic stewardship intervention at the study hospital.

METHODS

An electronic questionnaire (SurveyMonkey) was distributed to medical, nursing and pharmacy staff at a 750-bed teaching district general hospital with no specialist allergy service.

RESULTS

193 staff responded (58% medical, 31% nursing and 11% pharmacy). Virtually all staff had encountered patients who believed themselves to be penicillin allergic, but felt the patient's belief to be erroneous. The potential negative consequences of an incorrectly assigned penicillin allergy label were acknowledged by the majority of respondents. In total, 188/190 (99%) of staff thought patients having an incorrect allergy status to penicillin was a problem and required a solution. Staff reported they would feel confident using a validated evidence-based question tool to de-label patients incorrectly labelled as penicillin allergic if the process was supported by Trust management, although many still felt apprehensive about de-labelling patients for fear of patient harm through inappropriate de-labelling.

CONCLUSIONS

A penicillin allergy de-labelling intervention would be well supported by healthcare workers at the study hospital, demonstrating a receptive environment for this behavioural change intervention. Further exploration of the barriers and levers to introducing an intervention is required using behavioural change methodology in order to design a successful de-labelling intervention.

Discrepancies Between Patient Self-Reported and Electronic Health Record Documentation of Medication Allergies and Adverse Reactions in the Acute Care Setting: Room for Improvement

Background: Allergy information is commonly transcribed into an electronic health record (EHR) for all patients admitted to acute care hospital units by a licensed health care professional. The allergy history is utilized each time a new inpatient medication is prescribed to identify the patient's risk of having an allergic reaction and/or anaphylaxis. There is potential for negative consequences in cases where the allergy history is incorrectly documented. Objective: The objective of this study was to assess the discordance between documented allergy information in the EHR and verbally reported allergy information from a patient interview. Methods: Prospective, observational, nonrandomized study performed within a 2-month period during the Spring of 2016. The study was performed at a teaching community hospital in Chicago, Illinois. A total of 270 patients were interviewed on the general medicine (n = 216) and headache (n = 54) units regarding their medication allergies and reactions. The outcomes were discordance among EHR-documented and verbally stated medication allergies and reactions. Results: The agreement across all medications and reactions between the EHR and patient self-reported interview was 80.9%. There were 31 reactions (6.7%) that were verbally reported by patients but were not documented in the EHR (omissions) and 57 reactions (12.4%) that were verbally reported but were incorrectly documented in the EHR (incorrect documentations). Only 20 out of the 264 verbally reported reactions (7.5%) met the study definition of anaphylaxis. The highest rate of incorrect documentations occurred with opiate agonists, and the highest rate of omissions occurred with anticonvulsants. EHR documentation was more likely to be incorrect among patients who reported gastrointestinal reactions and was more likely to be correct among patients who reported cutaneous reactions. Conclusion: There was a high rate of discordance amid EHR-documented and verbally stated medication allergies and reactions. Errors among opiate agonists, anticonvulsants, and sulfa drugs were most prevalent.

Inappropriate labelling of patients as opioid allergic

Objectives. To investigate the incidence of patients being inappropriately labelled as allergic to opioid medications and to assess the effect that this label may have had on the subsequent prescribing of opioids.

Methods. A study was conducted on patients admitted to Toowoomba Hospital over a three month period as to their perceived opioid allergy status. In addition to medication history interview, pharmacists recorded data on any claimed drug allergy attributed to opioid medications. Events were classified depending on the probability of the event being an allergic or immunological drug reaction. Medical records and medication charts of identified patients were checked to determine if allergy status had any effect on opioid prescribing.

Results. Thirty patients reported an opioid allergy. Morphine and codeine were most commonly implicated, with nausea and vomiting the most likely adverse events. Six patients were classified as high probability of allergic reaction, although anaphylaxis wasn’t reported. Most allergy documentation was incomplete, with the nature of reaction seldom recorded. Despite a ‘supposed’ opioid allergy, 70% of patients were prescribed subsequent opioids. Of the six patients in the high probability group, four were prescribed opioids. Three received alternate opioids without incident, while nurses refused to administer the same previously implicated drug to the fourth patient.

Conclusion. Opioid prescribing did not appear to be influenced by a reported allergy. Ignoring ‘real’ allergies, however rare, may put patients at risk of severe consequences. Staff must be educated regarding the importance of recording accurately and thoroughly the specifics of patients’ medication allergies and its importance in future safe prescribing.

Documenting Penicillin Allergy: The Impact of Inconsistency

BACKGROUND

Allergy documentation is frequently inconsistent and incomplete. The impact of this variability on subsequent treatment is not well described.

OBJECTIVE

To determine how allergy documentation affects subsequent antibiotic choice.

DESIGN

Retrospective, cohort study.

PARTICIPANTS

232,616 adult patients seen by 199 primary care providers (PCPs) between January 1, 2009 and January 1, 2014 at an academic medical system.

MAIN MEASURES

Inter-physician variation in beta-lactam allergy documentation; antibiotic treatment following beta-lactam allergy documentation.

KEY RESULTS

15.6% of patients had a reported beta-lactam allergy. Of those patients, 39.8% had a specific allergen identified and 22.7% had allergic reaction characteristics documented. Variation between PCPs was greater than would be expected by chance (all p<0.001) in the percentage of their patients with a documented beta-lactam allergy (7.9% to 24.8%), identification of a specific allergen (e.g. amoxicillin as opposed to "penicillins") (24.0% to 58.2%) and documentation of the reaction characteristics (5.4% to 51.9%). After beta-lactam allergy documentation, patients were less likely to receive penicillins (Relative Risk [RR] 0.16 [95% Confidence Interval: 0.15-0.17]) and cephalosporins (RR 0.28 [95% CI 0.27-0.30]) and more likely to receive fluoroquinolones (RR 1.5 [95% CI 1.5-1.6]), clindamycin (RR 3.8 [95% CI 3.6-4.0]) and vancomycin (RR 5.0 [95% CI 4.3-5.8]). Among patients with beta-lactam allergy, rechallenge was more likely when a specific allergen was identified (RR 1.6 [95% CI 1.5-1.8]) and when reaction characteristics were documented (RR 2.0 [95% CI 1.8-2.2]).

CONCLUSIONS

Provider documentation of beta-lactam allergy is highly variable, and details of the allergy are infrequently documented. Classification of a patient as beta-lactam allergic and incomplete documentation regarding the details of the allergy lead to beta-lactam avoidance and use of other antimicrobial agents, behaviors that may adversely impact care quality and cost.

A randomised controlled trial and cost-effectiveness analysis of high-frequency oscillatory ventilation against conventional artificial ventilation for adults with acute respiratory distress syndrome. The OSCAR (OSCillation in ARDS) study

BACKGROUND

Patients with the acute respiratory distress syndrome (ARDS) require artificial ventilation but this treatment may produce secondary lung damage. High-frequency oscillatory ventilation (HFOV) may reduce this damage.

OBJECTIVES

To determine the clinical benefit and cost-effectiveness of HFOV in patients with ARDS compared with standard mechanical ventilation.

DESIGN

A parallel, randomised, unblinded clinical trial.

SETTING

UK intensive care units.

PARTICIPANTS

Mechanically ventilated patients with a partial pressure of oxygen in arterial blood/fractional concentration of inspired oxygen (P : F) ratio of 26.7 kPa (200 mmHg) or less and an expected duration of ventilation of at least 2 days at recruitment.

INTERVENTIONS

Treatment arm HFOV using a Novalung R100(®) ventilator (Metran Co. Ltd, Saitama, Japan) ventilator until the start of weaning. Control arm Conventional mechanical ventilation using the devices available in the participating centres.

MAIN OUTCOME MEASURES

The primary clinical outcome was all-cause mortality at 30 days after randomisation. The primary health economic outcome was the cost per quality-adjusted life-year (QALY) gained.

RESULTS

One hundred and sixty-six of 398 patients (41.7%) randomised to the HFOV group and 163 of 397 patients (41.1%) randomised to the conventional mechanical ventilation group died within 30 days of randomisation (p = 0.85), for an absolute difference of 0.6% [95% confidence interval (CI) -6.1% to 7.5%]. After adjustment for study centre, sex, Acute Physiology and Chronic Health Evaluation II score, and the initial P : F ratio, the odds ratio for survival in the conventional ventilation group was 1.03 (95% CI 0.75 to 1.40; p = 0.87 logistic regression). Survival analysis showed no difference in the probability of survival up to 12 months after randomisation. The average QALY at 1 year in the HFOV group was 0.302 compared to 0.246. This gives an incremental cost-effectiveness ratio (ICER) for the cost to society per QALY of £88,790 and an ICER for the cost to the NHS per QALY of £ 78,260.

CONCLUSIONS

The use of HFOV had no effect on 30-day mortality in adult patients undergoing mechanical ventilation for ARDS and no economic advantage. We suggest that further research into avoiding ventilator-induced lung injury should concentrate on ventilatory strategies other than HFOV.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN10416500.

A real-time prospective evaluation of clinical pharmaco-economic impact of diagnostic label of 'penicillin allergy' in a UK teaching hospital

AIMS

To perform a pharmaco-economic analysis of prescribing alternative antibiotics in patients with a diagnostic label of 'penicillin allergy' and assess whether collation of information from a structured history and liaison with the family physician could reduce costs.

METHODS

A prospective pro-forma-based interview of randomly selected in-patients and their family physician was used to assess the validity of the diagnostic label of 'penicillin allergy'. Cost analysis of prescription of alternative antibiotics was performed and compared with first-line agents.

RESULTS

102 patients were assessed and only 40% (n=41) were found to have a history consistent with penicillin hypersensitivity, 40% (n=41) were likely 'not allergic' and 20% (n=20) had 'indeterminate' reactions. Total cost of antibiotics prescribed for patients with penicillin allergy was 1.82-2.58-fold higher than for first-line antibiotics.

CONCLUSIONS

Obtaining a structured history from the patient and family physician alone can enable an accurate identification of penicillin allergy status. Total acquisition cost of second-line antibiotics is higher than if these patients were prescribed first-line antibiotics.

Knowledge of their own allergic sensitizations in asthmatic patients and its impact on the level of asthma control

BACKGROUND

Asthma guidelines recommend the adoption of allergen avoidance measures (AAM). To do so, patients need to know their own allergies. However, this degree of knowledge has not yet been assessed. The aims of this study were to determine, in allergic asthma patients: i)the degree of knowledge of their own allergic sensitizations; ii)the percentage of those who knew all their allergies and, in addition, adopted AAM against all of them, and iii)the possible impact of this degree of knowledge on the level of asthma control.

PATIENTS AND METHODS

Descriptive, prospective and multicentre study, including 147patients from 9 Respiratory Medicine outpatient clinics. After confirming the previous allergic asthma diagnosis, a questionnaire was completed. It included asthma control and severity levels, results of previous allergy tests, and the description and number of allergic sensitizations known by the patients and AAM followed.

RESULTS

Only 72 (49%) patients knew all their allergic sensitizations and only 48 (33%) were also following AAM against all the allergens to which they were allergic. No relationship was established between the degree of knowledge of their own allergies and the level of asthma control (P=.544).

CONCLUSIONS

Overall knowledge about the allergic nature of their disease among asthmatic patients attending Spanish Respiratory Medicine Departments is inadequate. Furthermore, a higher degree of knowledge of their allergies does not seem to lead, by itself, to better asthma control. Both findings seem to question the effectiveness of current educational strategies in this field and consequently, they should be revised.

Self-reported drug allergies and the diagnostic work-up in the surgical population

OBJECTIVE

The diagnostic work-up of a drug hypersensitivity reaction is indeed difficult. In general, medical documentation of allergic reactions in medical reports is usually highly deficient or non-existent. The aim of this study was to analyse the prevalence of self-reported drug allergies in the surgical population as well as the criteria used in the diagnosis of drug hypersensitivity reactions.

METHODS

A prospective study with the consecutive participation of 1439 patients, following surgical intervention, attended the Post-Operative Care Unit. Previously, as a routine process during the pre-anesthesia consultation, all patients were questioned about whether they had any drug allergies to report and diagnostic work-up.

RESULTS

The prevalence of self-reported drug allergies was 8.3% (119/1439): 3.6% considered themselves allergic to β-lactams and 2.4% to non-steroidal anti-inflammatory drugs. Approximately one-third of the subjects (40 out of the 119) had not been subjected to any allergy diagnostic procedure and with 79 (66.4%), the only diagnostic test used by the Allergy Unit had been the skin prick-test. None of those participating in the study had tryptase, methylhistamine, specific IgE or intradermal tests carried out to characterize the diagnosis of the allergic reaction.

CONCLUSIONS

These results show that self-reported drug allergies are highly prevalent and as yet little explored. It is an important prevalence which should bring about modifications to the prescription of certain medicaments. The medical personnel must be made aware of the need to make an accurate diagnosis of allergies to medicaments.

Reported allergies to antipsychotic agents in a long-term psychiatric hospital

The incidence of allergic reactions to antipsychotic agents is not well known but would be expected to be low. However, pharmacy records at a large state psychiatric hospital indicated surprisingly high rates of such allergies. We hypothesized that these high rates of reported allergies in the pharmacy database would not be supported by clinical history, but rather that they represented other side effects or past uncritical acceptance of casual patient reports. Method. Patients listed as having experienced allergies to antipsychotic medications were interviewed by two psychiatrists and any clinical evidence that suggested an allergy was noted. Results. Of 585 patients who were hospitalized on the day the data were reviewed, 138 patients (23.6%) were identified by the pharmacy as allergic to an antipsychotic medication, 79 of whom were available and consented to be interviewed. Of these 79 patients, 7 (8.9%) provided evidence of a true allergy and 12 (15.2%) provided evidence that suggested a remote possibility of an allergy. Of the 60 "allergic" patients who provided no evidence of an allergy, 57% reported a non-allergic adverse drug reaction (ADR) that may have accounted for the allergy assignment and 32% reported possible symptoms that might have done so. Length of stay was possibly associated with an unsupported allergy designation (p <0.07). Reported allergies to other psychotropic agents (p <0.02) or to nonpsychotropic agents (p <0.07) were associated with evidence of a "true" allergy to an antipsychotic agent. Conclusions. Allergies to antipsychotic medications may be much less common than suggested by clinical records. The examination of focused clinical histories from patients who have been reported to experience such "allergies" would likely expand the pool of available medications for many patients.

Skin testing in patients with hypersensitivity reactions to iodinated contrast media - a European multicenter study

BACKGROUND

Iodinated contrast media cause both immediate and nonimmediate hypersensitivity reactions. The aim of this prospective study was to determine the specificity and sensitivity of skin tests in patients who have experienced such reactions.

METHODS

Skin prick, intradermal and patch tests with a series of contrast media were conducted in 220 patients with either immediate or nonimmediate reaction. Positive skin tests were defined according to internationally accepted guidelines. Seventy-one never-exposed subjects and 11 subjects who had tolerated contrast medium exposure, served as negative controls.

RESULTS

Skin test specificity was 96-100%. For tests conducted within the time period from 2 to 6 months after the reaction, up to 50% of immediate reactors and up to 47% of nonimmediate reactors were skin test positive. For immediate reactors, the intradermal tests were the most sensitive, whereas delayed intradermal tests in combination with patch tests were needed for optimal sensitivity in nonimmediate reactors. Contrast medium cross-reactivity was more common in the nonimmediate than in the immediate group. Interestingly, 49% of immediate and 52% of nonimmediate symptoms occurred in previously unexposed patients. Many of these patients were skin test positive, indicating that they were already sensitized at the time of first contrast medium exposure.

CONCLUSIONS

These data suggest that at least 50% of hypersensitivity reactions to contrast media are caused by an immunological mechanism. Skin testing appears to be a useful tool for diagnosis of contrast medium allergy and may play an important role in selection of a safe product in previous reactors.

Prick-test evaluation to anaesthetics in patients attending a general allergy clinic

BACKGROUND AND OBJECTIVES

To analyse the prevalence of positive prick-tests to all medicaments normally checked in allergy units when a patient is suspected of being allergic to anaesthetics. To establish the degree of agreement between the antecedents of a previous history of an allergic reaction to a medicament and the positive result, or not, to the specific prick-test for the said medicament.

METHODS

This was a prospective study, during 2003 and 2004, which analysed 473 patients referred by their doctors to allergy units to make retrospective diagnoses of an allergy to a drug. The prick-test was done using the undiluted drug. All patients were tested for 41 drugs. These include antibiotics, trimethoprim-sulphamethoxazole, non-steroidal anti-inflammatory drugs (NSAIDs) and perioperative drugs (PD): neuromuscular blocking drugs, latex, iodine, local anaesthetics, hypnotics, opioids and coadjuvants. Cohen's Kappa Index was used to determine the degree of agreement.

RESULTS

71.5% of patients studied presented a positive prick-test. The largest number of positive cases was found in antibiotics (56.4%), followed by PD (15.6%), NSAIDs (14.4%) and trimethoprim-sulphamethoxazole (12.7%). Among PD, the highest prevalence of positive prick-tests was found for neuromuscular blocking drugs (5.3%). Agreement between the substance suspected of causing the allergic reaction and the positive prick-test was excellent for penicillin (Kappa = 0.74) and other antibiotics (Kappa = 0.721) and good for NSAIDs (Kappa = 0.47) and iodine (Kappa = 0.54).

CONCLUSIONS

The prevalence of patients with positive prick-tests to PD occurred in 15.6% in this prospective cohort. Neuromuscular blocking drugs were found to have the highest prevalence of positive prick-tests. There is positive agreement when the substance responsible for the allergic reaction is suspected, otherwise agreement is low.

The prevalence of suspected and challenge-verified penicillin allergy in a university hospital population

Suspected penicillin allergy is common among hospitalised patients, but the quality of the information given by the patient is often doubtful. Alleged penicillin allergic are likely to be treated with more toxic, broad-spectrum, and more expensive antibiotics, with effects on microbial resistance patterns and public economy as a consequence. We performed a cross-sectional case-control study with two visits to all clinical departments of a large university hospital in order to find in-patients with medical files labelled "penicillin allergy" or who reported penicillin allergy upon admission. Patient histories were obtained via a questionnaire, and they were offered investigation for penicillin allergy with specific IgE, basophil histamine release, skin prick tests, intradermal tests and drug challenge tests. Finally, the pharmaco-economical consequences of the penicillin allergy were estimated. In a cohort of 3642 patients, 96 fulfilled the inclusion criteria giving a point-prevalence of alleged penicillin allergy of 5% in a hospital in-patient population. Mean time elapsed since the alleged first reaction to penicillin was 20 years. The skin was the most frequently affected organ (82.2%), maculo-papular exanthema (35.4%) and urticaria (10.4%) being the most frequently reported reactions. 25% did not recall the time of their reaction. 82.2% did not remember the name of the penicillin they reacted to. 34.8% had been treated with penicillins after suspicion of penicillin allergy had been raised. None of these reacted to penicillins. 33.3% of the patients receiving antibiotics during their current hospitalisation were prescribed penicillins. 2% developed non-severe exanthema. The average acquisition costs for antibiotics to penicillin allergic patients were euro 278, compared to euro 119 had they been non-allergic. The prevalence of suspected penicillin allergy was lower than reported elsewhere. A substantial number of patients failed to recall basic information about their alleged allergy. Patients reporting penicillin allergy upon admission and labels stating penicillin allergy on medical files are ignored in almost a third of patients receiving antibiotics. The acquisition costs for antibiotics to penicillin allergic patients were higher, compared to the cost had the patients been non-allergic.

Discharge planning in A & E: part 2

Discharge of patients from A & E was considered by both the 1992 and 1996 Audit Commission reports. The 1992 Commission recommended that unnecessary return attendance for follow-up care should be reduced to a minimum, those requiring to make a return visit falling within the range of 10-15% of first attendances. Other hospital specialties, GP services and self care were identified as appropriate follow-up treatment. This places more emphasis on appropriate discharge advice for those who do not need to reattend, and this is an aspect of health promotion which largely goes unrecognized. The second part of this study explores how effectively A & E departments perform the role of giving appropriate discharge advice. Part I of the study, published in October 1997, covered the comprehensive discharge planning required for patients who belong to vulnerable groups and who commonly reattend.