Do patients receive appropriate information and treatment following bone mineral density measurements?

Poor agreement between self-reported diagnosis and bone mineral density results in the identification of osteoporosis

Osteoporosis is a major health concern, estimated to affect millions worldwide. Bone mineral density (BMD) assessment is not practical for many large-scale epidemiological studies resulting in the reliance of self-report methods to ascertain diagnostic information. The aim of the study was to assess the validity of self-reported diagnosis of osteoporosis in a population-based study. This study examined data collected from 906 men and 843 women participating in the Geelong Osteoporosis Study. Osteoporosis was self-reported and compared against results of BMD scans of the hip and spine. Validity was examined by calculating sensitivity, specificity, positive predictive value, negative predictive value, and kappa statistic. Osteoporosis was self-reported by 118 (6.7%) participants and identified using BMD results for 64 (3.7%) participants. Specificity and negative predictive value were good (95.1% and 96.0%, respectively), whereas sensitivity and positive predictive value were poor (35.9% and 31.4%, respectively). The overall level of agreement (kappa) was 0.29. The results changed only slightly when we included participants with osteopenia and adult fracture as osteoporotic. Reliance on self-report methods to ascertain osteoporosis status is not recommended.

Osteoporosis pharmacotherapy following bone densitometry: importance of patient beliefs and understanding of DXA results

SUMMARY

Persistence with osteoporosis therapy remains low and identification of factors associated with better persistence is essential in preventing osteoporosis and fractures. In this study, patient understanding of dual energy X-ray absorptiometry (DXA) results and beliefs in effects of treatment were associated with treatment initiation and persistence.

INTRODUCTION

The purpose of this study is to examine patient understanding of their DXA results and evaluate factors associated with initiation of and persistence with prescribed medication in first-time users of anti-osteoporotic agents. Self-reported DXA results reflect patient understanding of diagnosis and may influence acceptance of osteoporosis therapy. To improve patient understanding of DXA results, we provided written information to patients and their referring general practitioner (GP), and evaluated factors associated with osteoporosis treatment initiation and 1-year persistence.

METHODS

Information on diagnosis was mailed to 1,000 consecutive patients and their GPs after DXA testing. One year after, a questionnaire was mailed to all patients to evaluate self-report of DXA results, drug initiation and 1-year persistence. Quadratic weighted kappa was used to estimate agreement between self-report and actual DXA results. Multivariable logistic regression was used to evaluate predictors of understanding of diagnosis, and correlates of treatment initiation and persistence.

RESULTS

A total of 717 patients responded (72%). Overall, only 4% were unaware of DXA results. Agreement between self-reported and actual DXA results was very good (κ = 0.83); younger age and glucocorticoid use were associated with better understanding. Correctly reported DXA results was associated with treatment initiation (OR 4.3, 95% CI 1.2-15.1, p = 0.02), and greater beliefs in drug treatment benefits were associated with treatment initiation (OR 1.4, 95%CI 1.1-1.9, p = 0.006) and persistence with therapy (OR 1.8, 95% CI 1.2-2.7, p = 0.006).

CONCLUSION

Our findings suggest that written information provides over 80% of patients with a basic understanding of their DXA results. Communicating results in writing may improve patient understanding thereby also improve osteoporosis management and prevention.

Minimal error in self-report of having had DXA, but self-report of its results was poor

OBJECTIVE

To examine the validity of both self-report of having had dual-energy x-ray absorptiometry (DXA) and self-reported DXA test results.

METHODS

Participants were recruited in 2003 and 2004 from a population-based study of women aged 65-90 years examining osteoporosis management in Ontario, Canada (N=871). Women reporting having had a DXA were eligible and asked to report the results of their most recent test. Participant responses were compared against DXA reports obtained from physicians.

RESULTS

We obtained 413 (81%) physician records among the 510 women who reported having had a DXA test. Of these, the positive predictive value for self-report of having had a DXA was 93%. The weighted kappa statistic for the agreement between self-report and actual DXA results was 0.42 (95% confidence interval=0.34-0.49). Although 84% of those with normal bone reported this, only 29% of those with osteopenia and 62% with osteoporosis reported their results correctly. Self-report of a clinical diagnosis of osteoporosis was better among those with a low trauma fracture, yet underestimated osteoporosis prevalence by 24%.

CONCLUSION

There is minimal measurement error in self-report of having had a DXA test. Self-report of DXA results will underestimate osteoporosis prevalence and is not a good proxy for clinical diagnosis.

Correlation between patient recall of bone densitometry results and subsequent treatment adherence

Treatment of osteoporosis is often inadequate. One reason can be insufficient patient education following diagnostic bone densitometry (DXA). Therefore, we studied how patients are informed and treated following their first DXA. Individuals who had DXA at a rural hospital in Wisconsin were surveyed with a questionnaire regarding their post-test education and prescribed treatment. Their DXA results and the specialty of their clinician were also recorded. Eighty percent of the 1,014 participants were informed of their results. Of the 341 participants who had normal bone mineral density (BMD), 63% reported correct results, while only 31% of the 309 who had osteopenia and 50% of the 364 who had osteoporosis reported correct results. Accuracy in reporting was not affected by the patients' age or the specialty of their clinicians. Following DXA, 339 patients (33%) were started on medications; 86% of those remained on some prescribed therapy for osteoporosis, but 140 (41%) did not continue the initial medication. Reasons for discontinuation included side effects (48%) and cost (26%). Patients with low BMD who correctly reported their results were more likely to have received a medication and to continue to take it ( p <0.0001). Calcium supplements were recommended to 65% of those not taking calcium prior to DXA. Internists were more likely than family practitioners to recommend calcium, and their patients reported better medication adherence, as did those with osteoporosis compared with osteopenia. We conclude that, while most participants are informed of the results of their DXAs, the retained information may not be accurate. Correct understanding of DXA results may lead to higher treatment rates and better adherence to treatment among patients with low BMD.