NOVEL SURVEILLANCE FOR PENICILLIN USE IN OUTPATIENT SETTINGS IN MASSACHUSETTS MEDICAID

Background: Penicillin has been used clinically to treat infections since the 1940s, although shortly after its introduction, resistant organisms began to emerge. Enhanced penicillins were developed to improve their spectrum of activity and administration options. Massachusetts recently initiated a new system to monitor one critical component of the overall strategy to combat antimicrobial resistance: monitoring antimicrobial use. We selected penicillins as a first antibiotic class to analyze because they are the most frequently prescribed in the US. Methods: The MassHealth (US Medicaid) Pharmacy Program provides prescriptions and selected over-the-counter medications for an annual 1.3 million eligible low- and moderate-income recipients, except for those in managed care. Prescriptions included are mostly outpatient retail prescriptions. Monitoring is largely conducted for administrative purposes and public health has not previously used these data for surveillance of antimicrobial use. Units of measure represent prescriptions and are not available at the individual level, thus characteristics of the individual recipient of the prescription are not available. Pharmacy prescriptions are classified using the First Data Bank GC3 system. We selected all antibiotics in the penicillin class (W1A) prescribed from 2012-2016 and characterized these by month and year. Records were exported to and analyzed in Excel. Results: During July 1, 2012 through March 31, 2016 there were a total of 59,515,143 prescriptions for any antibiotic in the penicillin class in MassHealth records from outpatient retail settings. The mean per month was 1,322,559, with a monthly range of 866,201 to 2,031,017. The median was 1,309,879. The exact number of eligible patients fluctuates and was not available for this analysis; however, assuming 1.3 million per year, and during the most recent full year for which data were available (2015), there were 16,462,036 prescriptions yielding a rate of 12,663 prescriptions per 1000 patients. Compared to the national rate of 193 per 1000, our finding represents a rate 65.6 times the national rate. Plotted by month, there was a seasonal pattern with consistent peaks during winter months and nadirs during summer months. Conclusions: Preliminary findings from prescriptions in MassHealth indicate that penicillins may be overprescribed. Future efforts could include feedback of use patterns to providers in support of outpatient antimicrobial stewardship programs.