We agree that no economic evaluation of drug formulary policy is complete without careful consideration of its effects on resource utilization in other health care sectors. In our article we emphasized the need for more holistic reviews of reference-based pricing and restricted-access policies, with attention to outcomes such as health status, patient satisfaction and consumption of nonpharmaceutical resources.1 It is conceivable that patients who must switch drugs because of formulary constraints suffer more relapses, visit their physicians more frequently to review alternatives, undergo more new tests and procedures, and eventually become dissatisfied.
A recent review of health service utilization in British Columbia identified no significant changes associated with the introduction of reference-based pricing for histamine-2 receptor antagonists.2 However, Westbrook3 reported significant increases in rates of endoscopy after the introduction of a special authority policy for PPIs in Australia. These discrepant findings suggest that drug reimbursement policies differ in their impact on utilization of nonpharmaceutical resources. Indeed, the Australian policy required endoscopic proof of esophagitis for reimbursement, whereas British Columbia exempted gastroenterologists from prescribing restrictions. Further research is needed to clarify the impact of alternative drug formulary policies and to identify an optimal approach. We commend Westbrook for her efforts in this regard.
John K. Marshall Assistant Professor Department of Medicine Paul Grootendorst Assistant Professor Department of Clinical Epidemiology and Biostatistics Anne M. Holbrook Associate Professor Department of Medicine McMaster University Hamilton, Ont.