In uinvariate analysis, age and presence of chronic illness (eg, cancer, diabetes) were significant predictors of screening test completion during both 2007 and 2008. Older women with comorbidities are probably seen more often in their primary care clinic, which increases the opportunity to capture gaps in preventive care. The actual number of clinic visits that each patient made during each year was not examined and potentially would constitute a variable in osteoporosis screening completion rates.
With multivariate analysis, age remains an independent predictor of screening completion. While it is an established risk factor for osteoporosis and would generally trigger screening,9
this study showed advancing age to be associated with a decreased likelihood of completing the screening test; women aged 80 years or older are less likely to be screened. Indeed, increasing age by itself has been identified as a barrier to effective osteoporosis care, along with the presence of dementia, lack of treatment adherence, and inadequate social support among vulnerable elderly patients.10
Likewise, it is common practice for women in this age group who present with vertebral or hip fracture to be clinically treated for osteoporosis without a screening test. Decreased life expectancy may also limit screening. One study identified greater concern about developing osteoporosis and better knowledge of bone mineral density (BMD) testing as 2 determinants of the readiness to undergo osteoporosis screening in older, high-risk patients.11
A closer look at factors that account for decreased screening among elderly patients in this study would be useful in designing effective practice interventions to improve osteoporosis diagnosis and management.
Race and residence are also significantly associated with increased screening rates. Because more than two thirds of the women in this study are white and reside in predominantly white Olmsted County, the results could have been skewed. However, the data were unchanged even in the final, stable multivariate model. There was a trend toward increased test completion among Asian women in 2008, but the number is too low to determine statistical significance.
Two diseases, cancer and rheumatologic illness, are associated with higher screening rates. Other studies have observed the correlation between osteoporosis and the presence of these conditions because of the underlying disease pathology and/or treatment (eg, corticosteroids).12
Therefore, their presence is likely to trigger an order for a DEXA test. Patients with these comorbidities also require frequent clinic visits, allowing greater opportunity to screen.
There was a statistically significant increase in the osteoporosis screening rate from 2007 to 2008. This result confirmed the finding of a previous study, which showed that use of a clinical decision-support tool significantly improved the osteoporosis screening rate among eligible women seen in the primary care setting.7
Screening of eligible women is likely to be completed after a full examination. This finding was also observed in a previous study that looked at screening orders for abdominal aortic aneurysm in a primary care practice; the test was more likely to be ordered at a general or full examination than at an acute care or follow-up examination.8
More time is usually allotted for a full examination, which provides a greater opportunity to address preventive health screening.
The characteristics and number of women seen for full and limited examinations in both years were similar; the only factor that would account for the statistically significant association of the year 2008 with screening completion was the availability of GDMS. This finding reflects the utility of the tool in improving preventive care practice across primary care population groups and supports the hypothesis that it appears to be an independent predictor of osteoporosis screening completion.
More eligible patients were seen in family medicine clinics than in primary care internal medicine; however, test ordering did not differ statistically between the two specialty areas. This also was observed in the retrospective study on abdominal aortic aneurysm screening in which no difference was seen in the ordering rates among providers with different roles or of different sexes.8
This study identified factors that predict osteoporosis screening completion by primary care providers in an academic institution in the Midwestern United States, and results may not be generalizable to community-based primary care practices in other geographic areas. Most of the women in the study were white, which limits the application of results to other ethnic and minority groups. It would be interesting to see results from a larger, multicenter study with a more diverse ethnic population.