OBJECTIVE: To evaluate patient and physician factors associated with prevention of glucocorticoid-induced osteoporosis and to describe temporal trends in screening and prevention of glucocorticoid-induced osteoporosis. METHODS: Using databases from a national managed care organization, enrollees who had been prescribed glucocorticoids (taken for at least 60 days) during an 18-month period were identified. Administrative data from January 2001 through June 2003 and linked survey data from October 2003 were examined for measurement of bone mass, prescription of antiresorptive medication, and use of over-the-counter calcium and/or vitamin D treatment. Factors associated with screening and bone-protective therapies were identified using multivariable logistic regression, focusing on physician specialty and survey respondent ethnicity. Trends in glucocorticoid-induced osteoporosis prevention were assessed using administrative data from 2001-2003 versus 1995-1998. RESULTS: We identified 6,281 patients who were prescribed glucocorticoids in 2001-2003 (mean +/- SD prescribed prednisone-equivalent dosage 16 +/- 14 mg/day). Forty-two percent underwent bone mass measurement and/or were prescribed bone-protective medication; rates were lowest for men (25%). Compared with patients of internists, the odds of bone mass measurement were lowest among patients prescribed glucocorticoids by family physicians (odds ratio [OR] 0.56 [95% confidence interval] [95% CI] 0.30-1.04) and highest among patients prescribed glucocorticoids by rheumatologists (OR 1.48 [95% CI 1.06-2.08]). Patients prescribed glucocorticoids by gastroenterologists were less likely to be treated with antiresorptive agents (OR 0.49 [95% CI 0.28-0.86]). African American patients were less likely than white patients to be screened (OR 0.55 [95% CI 0.40-0.75]) or treated (OR 0.71 [95% CI 0.51-0.98]). The frequency of bone mass measurement among glucocorticoid-treated patients in 2001-2003 increased 3-fold compared with 1995-1998, and the use of prescription antiresorptive medication increased approximately 2-fold. CONCLUSION: Despite significant temporal increases in the frequency of screening for and treatment of glucocorticoid-induced osteoporosis, absolute rates remain low, especially among men, African Americans, and patients of certain physician specialties.