Skin tests, decision-making aids improve antibiotic use

Antibiotics such as penicillin and cephalosporin are vitally important to effective healthcare, but allergic patients miss out on the benefits. Researchers from Massachusetts General Hospital (MGH) and Brigham and Women's Hospital (BWH) conducted a study using penicillin allergy skin tests and computerized decision support tools to examine individuals who were previously labeled as allergic to penicillin.

The study, published in the Journal of Allergy and Clinical Immunology, tested both penicillin allergy skin tests and a computerized decision support tool to provide antibiotics to patients who believed they were allergic. Over two years, researchers tested these approaches on BWH penicillin-allergic patients who needed antibiotic treatment.

"Ten to 15 percent of hospitalized patients have a penicillin allergy in their medical record, but studies have shown that more than 95 percent are not really allergic," said Kimberly Blumenthal, MD, MSc, co-lead and corresponding author of the paper. "We know that over-reporting of penicillin allergies has a negative impact on patient care, as the alternative drugs often used are less effective, more toxic and can both leave patients vulnerable to dangerous C. difficile infection and increase antibiotic resistance in the community. The need to address over-reported penicillin allergy has been widely acknowledged, but how to do that has remained unclear."

The study was split into three segments, the first covering five months followed by two seven-month segments. The first segment treated patients with either a skin test or test dosing after a referral by a primary care physicians and consultation with an allergy specialist. The second segment screened penicillin allergic patients in need of antibiotics for skin-test eligibility. The last segment included having physicians access the computerized decision support system to categorize patients into very low risk, low risk, medium/ high risk and serious reaction, according to a patient’s allergy severity to penicillin or cephalosporin.

Results showed that using the decision support tool was able to double the rate of antibiotic prescription. The test was not only effective in revealing false allergies to penicillin and cephalosporin, but also showing the effectiveness of decision support tools in offering higher quality care. During the study, 112 providers completed the support tool protocol, and views of informational webpages topped 300 showing a high use of the tool for improving care.

"We found that addressing penicillin allergy by either method could lead to an overall improvement in antibiotic choice for these patients," Blumenthal said. "We don't want to discourage any method of evaluation because even thinking about whether a patient's penicillin allergy is true could lead a provider to make a different management decision. Even here at MGH, we estimated that skin testing all patients with recorded penicillin allergy would be impractical without a significant staff increase or technological guidance."