Factors associated with the ordering of a DXA scan in glucocorticoid treated patients

GEETANJLI SANGWAN

Advisor: Tilahun Adera, Ph.D.

Preceptor: Robert Adler, M.D.

Objective: To determine the factors associated with a physician’s decision to order a DXA scan as a preventive measure for glucocorticoid-induced osteoporosis in patients who have been on oral prednisone at a dose equivalent to 7.5 mg/day for 90 days or more.

Method: Glucocorticoid treated outpatients seen over 15 months (Oct 2001 - Dec 2002) at McGuire VAMC, Richmond were identified by a pharmacy computer search at the same institute. The study population consisted of 120 patients for whom a DXA scan was ordered and 100 patients without a DXA scan order. The data collected from the electronic medical records of the patients included patient demographic characteristics, medical history and the clinic by which prednisone was prescribed. Basic descriptive characteristics (proportional distributions, means, and prevalence) were determined. Data analysis was performed using unpaired t tests and chi-square analysis. A stepwise logistic regression analysis was done to ascertain the independent predictors of ordering a DXA scan as an intervention for the prevention of glucocorticoid-induced osteoporosis.

Results: Whites are 2.4 times (C. I. = 1.2, 4.7) more likely to get a DXA scan order as compared to African Americans and other minorities. Rheumatologists are 3 times (C. I. = 1.5, 6.1) more likely to order a DXA scan for their patients as compared to the physicians of other specialties. Patients with a rheumatic diagnosis such as rheumatoid arthritis are 2.5 times (C. I. = 1.2, 4.9) more likely to get a referral for a DXA scan as compared to those with other diagnoses. Overweight patients with a BMI between 25 and 30 are 3.1 times (C. I. = 1.3, 7.3) more likely to get a DXA scan as compared to other patients. Patients who received a glucocorticoid dose of more than 10 mg/day over a 15 month period are 3.1 times (C. I. = 1.2, 7.5) more likely to get a DXA scan order as compared to those who received lower doses.

Conclusion: The findings of this study suggest that whites are 2.4 times more likely to get a DXA scan order as compared to African Americans and other patients, and rheumatology as a physician specialty is an important predictor of bone density testing. Thus, educational efforts should be directed towards increasing awareness of the importance of glucocorticoid-induced osteoporosis so as to overcome this racial disparity and to encourage physicians of other specialties to order a DXA scan for all patients receiving long-term glucocorticoid treatment.