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

Abstract

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.

Appendix

Example of personalized letter sent to patients and physicians regarding DXA test results. The original letters were written in Danish, and thus this is an example only based on a translation into English

Ms XX

Examination Date 12-05-2010

Your DXA bone density examination shows the following

The scan shows osteoporosis. (Other diseases such as lack of vitamin D can give rise to a similar result).

According to the information given to us, your risk factors for osteoporosis were the following

Smoking.

Comments to you from the doctor

The bone density is reduced to a degree corresponding to osteoporosis (bone fragility). Your risk of suffering a bone fracture within the next 10 years was estimated to about 10%, based on your DXA result, age, and sex. The risk of fractures can be reduced through medical treatment for osteoporosis. I recommend that you consult your GP for advice on this. In addition, smoking reduces bone mass and increases your risk of a fracture. In my opinion, the DXA scan should be repeated in 2 years.

Osteoporosis (bone fragility) is a loss of bone tissue and bone mineral, which leads to increased risk of broken bones after minor loads or falls. It is important to show due consideration and avoid lifting heavy burdens or bending the back while lifting. Preventing falls is important, particularly in the elderly. If you are working, you should seek advice from your doctor regarding how much lifting could be considered safe and whether some forms of work should not be undertaken. Medical treatment is possible in every case.

Detailed information about the DXA examination

You can find the detailed results below. The numbers are particularly important when you seek advice from health professionals, e.g., your GP.

$$ \begin{array}{*{20}{c}} {{\hbox{T - score, hip}}} \hfill & { - 2.0} \hfill & {{\hbox{T - score, spine}}} \hfill & { - 3.0} \hfill \\\end{array} $$

T-score is a measure of whether one has osteoporosis. A more negative number indicates a lower bone density. Scores below −2.5 define osteoporosis.

$$ \begin{array}{*{20}{c}} {{\hbox{Z - score, hip}}} \hfill & { - 1.2} \hfill & {{\hbox{Z - score, spine }}} \hfill & { - 2.1} \hfill \\\end{array} $$

Z-score is a measure of bone density compared with that of others of the same sex and age.

A positive number indicates that your bone density is above average—a negative number that it is below average. Most people have a Z-score between −2 and +2.

Yours sincerely,

Dr. Nn.