BACKGROUND: High-dose corticosteroid exposure is associated with increased risk of bone loss and osteoporotic fractures. OBJECTIVE: To examine high-dose corticosteroid use and osteoporosis screening and treatment trends in patients receiving high-dose oral or inhaled corticosteroids in a large managed care organization. METHODS: We reviewed electronic records of inhaled and oral corticosteroid use and osteoporosis intervention in 2002 among patients 20 years or older and developed algorithms to quantitate high cumulative exposure to corticosteroids. RESULTS: High-dose exposure to corticosteroids was found in 18,737 health plan members (0.8%) (7,757 men [41%] and 10.980 women [59%]). Prevalence increased with age, from 0.4% (age range, 20-49 years) to 1% (age range, 50-64 years) and 2% (age range, or =75 years). Of high-dose users, 72% used only oral, 15% used only inhaled, and 13% used combined oral and inhaled corticosteroids. Bone densitometry was performed in 9% of men and 27% of women exposed to oral corticosteroids and in 4% of men and 23% of women exposed to inhaled corticosteroids. Prescriptions for osteoporosis drugs were filled by 6% of men and 11% of women receiving oral corticosteroids and by 1% of men and 5% of women receiving inhaled corticosteroids. CONCLUSION: Approximately 1 in 125 people 20 years or older were exposed to high doses of corticosteroids; oral exposure was 3 times more common than inhaled exposure. Most exposed patients do not receive bone density testing or osteoporosis drug prophylaxis. Use of prescription databases to identify high-dose oral and inhaled corticosteroid users can enable focused intervention to reduce bone loss and potentially reduce the risk of osteoporotic fractures.