Many Patients with Skin Infection Don't Complete Antibiotics

Researchers in California suggest that patient adherence with oral antibiotic therapy for skin and soft tissue infections after hospital discharge appears to be low and associated with poor clinical outcomes. Published online on February 29 in the peer-reviewed journal, Antimicrobial Agents and Chemotherapy, the study found that patients in this population commonly overstate their medication adherence, possibly making identification of those who are at risk for non-adherence and poor outcomes challenging.

In this first study of its kind, the investigators found that nearly half (46%) of patients with Staphylococcus aureus skin and soft tissue had a poor clinical response at 30 days after hospital discharge, resulting in a new infection or the need for additional treatment for their existing skin and soft tissue infection. The poor clinical response was likely tied to the finding of an average electronically measured adherence to antibiotic therapy of only 57%, a significantly different adherence rate than that reported by patients themselves (96%).

Indeed, in a multivariable model, poor clinical response at 30 days was associated with lower adherence, being non-diabetic, and lack of illicit drug use within the previous 12 months. Higher rates of non-adherence to antibiotic regimens were also found among patients who were prescribed more than one antibiotic upon hospital discharge, were not treated by the same healthcare provider for follow-up visits, or felt they did not have a regular healthcare provider.

Despite previous research showing that skin and soft tissue infections are common and frequently recur, and that poor adherence to antibiotic therapy can result in suboptimal outcomes, adherence to oral antibiotics for these infections and the relationship between adherence and clinical outcomes had not been examined in this patient population prior to the current study.

For the study, lead researcher Loren G. Miller, MD, MPH, Division of Infectious Diseases, Harbor-UCLA Medical Center, and colleagues enrolled 188 adult patients hospitalized with uncomplicated skin and soft tissue infections caused by S. aureus who were being discharged with oral antibiotics to complete therapy. Participants’ pill bottles were fitted with an electronic bottle cap that recorded each pill bottle opening. All participants underwent an in-person standardized questionnaire at enrollment as well as at 14 and 30 days. Miller and colleagues reviewed participants’ medical records to determine outcomes.

The primary outcome for the study was poor clinical response, which the study team defined as a change in antibiotic therapy, new incision and drainage procedure, or a new skin infection within 30 days or hospital discharge. Of the 188 participants, 87 had complete data available for analysis, among whom 40 needed additional treatment within 30 days of leaving the hospital.

“We have seen similar differences and similar failures to take all the prescribed medications in many other conditions, including hypertension, diabetes and HIV,” said Miller. “But these failures have never been studied in skin infections or linked with clinical outcomes. These findings suggest that we need better methods to have patients receive antibiotics for skin infections, such as counseling them on the importance of adhering to the medication dosing or by using newer antibiotics that require only once-weekly dosing.”