Health care system, provider and patient predictors of prescribing quality and efficiency

Understanding factors influencing medication utilization and provider prescribing behavior has important implications for the quality improvement and cost containment in health care. This dissertation seeks to shed light on the quality and efficiency of medication prescribing. Chapter one examines the association between Medicare Part D plan features and choice of generic antidepressants, antidiabetics, and statins using Medicare claims data. Low cost-sharing for generics, large differentials in cost-sharing for generic vs. brand drugs, and tools such as prior authorization and step therapy are associated with higher generic drug use. Modifying the benefit design and utilization management of Medicare prescription drug plans might increase generic use, which could generate substantial savings for the Medicare program and for beneficiaries. Chapter two examines physician antipsychotic prescribing behavior in a large Medicaid program. By linking multiple data sources and using the multiple membership modeling approach, we examine the degree to which psychiatrists are diversified vs. concentrated in their choice of antipsychotic medication and identify factors associated with the concentration of prescribing. Antipsychotic prescribing behavior is relatively concentrated and varies substantially across psychiatrists regularly prescribing antipsychotics. Several characteristics of the treated patient population and physicians are significantly associated with antipsychotic prescribing. The few characteristics of organizations examined have little influence over psychiatrist prescribing behavior. Chapter three assesses provider-level clozapine and antipsychotic polypharmacy practices – one with strong evidence base and the other with little support. Using multiple years’ claims data in a large Medicaid program, we find provider-level underuse of clozapine and use of non-evidence supported practice of non-clozapine antipsychotic polypharmacy. However, these prescribing practices vary tremendously across providers. In particular, a sizable portion of providers use more antipsychotic polypharmacy than clozapine to their patients. Quality initiatives may take actions to improve evidence-based practice and to decrease unsupported practices in the management of antipsychotic drug use. This dissertation has important implications for public health because appropriate prescribing can alleviate tremendous health and economic burdens while inappropriate prescribing can generate substantial costs and increase risk of undesirable consequences. Understanding how providers make prescribing decisions points to potential opportunities for improving the quality of care and reducing cost through altering providers’ prescribing behavior.\u