A survey of physician practice and knowledge of drug allergy at a university medical center.

Adverse drug reactions affect 10% to 20% of hospitalized patients and more than 7% of the general population. It has been estimated that adverse drug reactions may constitute the sixth leading cause of death in the United States after heart disease, cancer, stroke, pulmonary disease, and accidents. Physicians regularly face the question of whether a patient-reported allergy is accurate and how the drug allergy (DA) will affect patient care. Patients are commonly labeled as being drug allergic due to vague symptoms that do not correspond to a true allergic reaction. Patients with reported allergy to penicillin may be treated with more expensive nonpenicillin class antibiotics. Trends in antibiotic prescription rates are showing an increase in the use of broad-spectrum antibiotics, namely azithromycin and quinolones. Ultimately, the physician must make an educated decision about the validity of reported DA. Allergy to penicillin is regularly found in medical charts. Up to 10% of all patients report a penicillin allergy. Patients may attribute nonallergic rashes during viral illness, headaches, or gastrointestinal symptoms to a penicillin allergy. Most patients who report a penicillin allergy can tolerate penicillin, but often physicians will prescribe a different class of antibiotics. It also has been reported that penicillin allergy and labels that state penicillin allergy on medical files are ignored in one-third of patients who receive antibiotics. How a physician interprets a reported penicillin allergy depends on his or her knowledge of DA and affects future patient care. The objective of the study was to determine current physician knowledge and practice patterns regarding DA at our university medical center. Previous studies looked at physician knowledge and approach toward penicillin allergy but not DA outside of penicillin. In our study, we hoped to further explore DA and physician practice throughout various medical specialties and training levels. The study was approved by the Saint Louis University Institutional Review Board. We created a survey through SurveyMonkey (Palo Alto, CA) that looked at physician management of patients with DA, knowledge of DA, and knowledge of clinical indications for skin testing (ST) and desensitization. The survey contained 12 questions (Table I), but questions 8 and 9 were scored as 11 different questions each, which led to 32 total questions, 7 of which were training and/or practice questions, and 25 of which were knowledge questions. Initial questions collected demographic information, including level of training and medical specialty. Later questions addressed DA practice patterns and DA knowledge. E-mails of the survey were sent to 986 physicians in all departments at Saint Louis University, including attending physicians, residents, and interns. The responses to the survey were directly entered into the SurveyMonkey online database. Descriptive statistics and unpaired t tests for comparisons among groups were performed by using SAS 9.1 (SAS Institute, Cary, NC). A P < .05 was used for evaluation of statistical significance. A total of 242 of the 986 surveys were completed by using SurveyMonkey, for a response rate of 24.5%. When looking at the training level, 45.04% of responders identified themselves as attending physicians. The response rate was evenly distributed throughout specialties, with the largest response from internal medicine, at 17.36% (Figure 1). We determined the level of experience by years in practice since medical school, and the mean for all responders was 11.64 years in practice. The average percentage of patients seen by respondents who reported any DA was 31.84%. Respondents thought that only 30.64% of patients who reported DA would react if given the suspected drug; however, only 15.05% stated that they would give the drug in this situation. Of the respondents, 48.76% reported previously performing or ordering a consult for drug desensitization. Of the 25 knowledge questions about DA, the average score for the cohort was 16.65 of 25 (66.6%). The knowledge questions also included a list of 11 drugs paired with clinical manifestations and asked respondents to pick the correct pairings as indications for ST or desensitization. Urticaria with penicillin was the most frequent correct answer as a clinical indication for ST (83.06%) and desensitization (69.0%); however, only 43.0% and 47.9% of respondents cited anaphylaxis with piperacillin as an indication for ST and desensitization, respectively. When looking at the pairings for ST and desensitization in relationship to aspirin, respondents generally knew that ST is not performed in the evaluation of aspirin allergy. In comparison, the pairings of aspirin to anaphylaxis, angioedema, and aspirin exacerbated respiratory disease (AERD) as an indication for desensitization were less frequently answered correctly. For anaphylaxis, angioedema, and AERD, only 31.40%, 19.83%, and 14.87% of respondents, respectively, chose desensitization as a treatment option. The final question addressed the correct test for confirmation of anaphylaxis, and 13.64% of respondents chose serum total tryptase as the correct answer. Although no significant differences were found regarding DA knowledge between attending physicians and residents, or between primary care physicians and specialists, physicians with any internal medicine training did score significantly higher than those without such training (average correct, 17.36 [69.44%] vs 16.31 [65%]; P < .01). In our study, we surveyed current physician practice habits in patients with a DA and physician knowledge of DA. To our knowledge, this is the first study that looked at nonallergyetrained physician knowledge of desensitization for various medications. Previous DA studies also showed a need for further physician education to address DA. Previous DA surveys looked at the prescribing habits of physicians in relation to penicillin