Over and under-utilization of cyclooxygenase-2 selective inhibitors by primary care physicians and specialists: the tortoise and the hare revisited.

OBJECTIVES: To compare prescribing trends and appropriateness of use of traditional and cyclooxygenase-2 selective (COX-2) nonsteroidal anti-inflammatory drugs (NSAIDs) by primary care physicians (PCPs) and specialists.
DESIGN: Retrospective cohort study. PATIENTS: One thousand five hundred and seventy-six adult patients continuously enrolled for at least 1 year with an independent practice association of a University-associated managed care plan who were started on a traditional NSAID or a COX-2 inhibitor from 1999 to 2002 and received at least 3 separate medication fills. MEASUREMENTS: Physician specialty was identified from office visits. Appropriateness of utilization was based on gastrointestinal risk characteristics.
RESULTS: Primary care patients were younger and less likely to have comorbid conditions. Despite similar GI risk, COX-2 use among patients seen by PCPs was half that of patients seen by specialists (21% vs 44%, P<.001). While PCPs overused cyclooxygenase-2-specific inhibitors (COX-2s) less often than specialists (19% vs 41%, P<.001), they also tended to underuse COX-2s in patients who were at increased GI risk (46% vs 32%, P=.063). This represents a 3-fold and 8-fold difference in overuse versus underuse for PCPs and specialists, respectively.
CONCLUSIONS: Using COX-2s as a model for physician adoption of new therapeutic agents, specialists were more likely to use these new medications for patients likely to benefit but were also significantly more likely to use them for patients without a clear indication. This study demonstrates the tension between appropriate adoption of innovative therapies for those individuals who would benefit from their use and those individuals who would receive no added clinical benefit but would incur added cost and be placed at increased risk.