Date of Award


Degree Type


Degree Name

Doctor of Philosophy in Pharmaceutical Sciences


Interdepartmental Program

First Advisor

Paul Larrat


Background: Respiratory tract infections (RTls) are considered to be the primary reason for prescribing antibiotics in community practice, accounting for 75% of prescribed antibiotics. Only some of these conditions, acute non pneumonic RTls (ARTls), are the focus of this dissertation. ARTls include acute cases of nasopharyngitis (common cold), sinusitis, pharyngitis (sore throat), laryngitis, and bronchitis. These conditions are, in many cases, caused by a virus and they usually resolve naturally without the use of any medication.

Objectives: Many studies have demonstrated the inappropriate overutilization of antibiotics in certain ARTls. This practice may be associated with high unnecessary costs and potential for resistance from such use. Factors behind this practice are many. Some have been studied and many still need more exploration. The objectives of this study were to a) provide specific information on the influence of prescription drug coverage on antibiotic utilization; b) the influence of prescribing antibiotics on patient reported satisfaction; c) explore the effect of drug copayment on prescribing of antibiotics. The study also estimated the total cost in dollars that may be saved from the direct cost of antibiotics, to both the insurers and patients, when paying for these medications that may be used inappropriately.

Methods: A cross-sectional retrospective study of prescription events associated with different ARTls was identified from the Household Component (HC) of the 1996 Medical Expenditure Panel Survey (MEPS). Descriptive and logistic regression analyses were conducted to explore the relationship between the different variables in the study with antibiotic utilization. The perspective taken in these studies was that of a healthcare insurer.

Results: The study found that the likelihood of being prescribed an antibiotic, which may be of high cost and unnecessary, is greater when patients have prescription drug coverage. However, no effects were related to drug copayment on antibiotic utilization. The study also suggests that in this population the level of patient satisfaction with the quality of care provided is not influenced by whether antibiotics are prescribed or not. It was also found that millions of dollars may be wasted yearly on these medications.

Conclusion: The findings from this study provide more insight to insurers and designers of drug coverage plans, who should closely monitor prescribing patterns for these conditions to avoid unnecessary cost as well as resistance from such antibiotics. They should not focus on antibiotic prescribing as a means of patient satisfaction, but on the appropriate use of such antibiotics and the avoidance of unwanted effects. More research is needed to examine the effect of the different copayment tier systems introduced in the last couple of years on the utilization of these drugs and whether they may help reduce the inappropriate use of these drugs.