Cost impact of using specific cyclooxygenase II inhibitors in orthopedic outpatients at Lerdsin Hospital

Abstract

Utilization of specific COX II Inhibitors (C2I) has been increasing in several countries, although their cost is substantially greater than NSAIDs. C2I have equal efficacy to NSAIDs, but are associated with a lower risk of upper gastrointestinal (GI) adverse effects, particularly in high risk patients. In Thailand, expenditure of C2I at national level has dramatically increased from 65.2 million Baht in 1999 to 451.4 Baht in 2001. Yet, no studies have addressed the impact of the increased cost of these drugs. The purposes of this study were to characterize the patterns of C2I use, and to determine cost impact of C2I use in patients who are at low risk and high risk for gastrointestinal adverse effects. This study was a retrospective review of patients receiving prescriptions for C2I or NSAIDs when visiting the orthopedic outpatient clinic at Lerdsin Hospital during November and December 2002. The medical records of 1,113 patients were reviewed. Of these, 519 received C2I and 594 received NSAIDs. The National Institute for Clinical Excellence of United Kingdom Guidelines for C2I use was employed to determine whether the patients receiving C2I were at high risk of adverse gastrointestinal events. Two hundred and eight (40.1%) patients receiving C2I and 113 (19.0%) patients receiving NSAIDs were considered to be at high risk for upper gastrointestinal adverse effects. Of the patients receiving prescriptions for C2I, 112 (21.6%) received C2I alone and 159 (30.6%) received Gastro-Protective Agents in addition to C2I. The study results showed that prescribing of C2I compared with NSAIDs used in actual practice among patients who were not at high risk of adverse gastrointestinal events resulting in excessive expenditure of 2,431,228.56 Baht/year. Compared with the three drugs which were most frequently used in the hospital and could be used for standard treatment including diclofenac, Voltaren®, and ibuprofen 400 mg, cost waste of C2I use were 3,398,182.56, 1,689,769.80 or 3,241,482.48 Baht/year, respectively. Because of the high cost impact of C2I, it is necessary to establish clinical practice guidelines for prescribing restriction and prospective drug use review for C2I.