Regional differences in treatment for osteoporosis. The Global Longitudinal Study of Osteoporosis in Women (GLOW)
Highlights
► The likelihood of osteoporosis treatment varies across geographic regions. ► These differences cannot be explained by regional differences in risk factors. ► Large proportions of women at fracture risk do not receive preventive treatment. ► These data suggest patterns of both under and over treatment.
Introduction
Fractures in older women reduce quality of life and contribute to increases in morbidity and mortality [1]. Optimal reduction of fractures requires that treatment decisions be based on treating those at greatest risk of fracture, who are likely to benefit from anti-osteoporosis medication (AOM).
Wide variation exists in the application of treatment, with a low overall prevalence of treatment for women at risk of fracture [2]. The recognition that clear, consistent, and widely accepted guidance for treatment has been lacking, has resulted in the development of tools for identifying those most at risk of fracture [3], [4], although these tools have become widely available only recently.
The assessment of regional variation in rates of specific medical treatments and procedures has been used to identify inconsistency in the application of medical and surgical interventions [5], and to identify the need for more consistent application of treatment guidelines. To the extent that regional and national variations exist in the frequency of treatment to reduce fracture risk, these differences could be driven by dissimilar patterns of risk or practice. It is important therefore to account for differences in the distribution of fracture risk between regions if the goal is to assess variation in treatment practices. The prevalence of risk factors for fragility fracture has been documented in national and regional reports, but studies have varied in their methods, so that appropriate comparisons across regions have been difficult [6], [7], [8], [9]. Estimates of prevalence for a number of risk factors have varied by as much as fivefold to ninefold [10]. For these reasons, it is important that data on risk factors and treatment in different regions are collected using a uniform method from a large number of women from different countries. In this study, data on treatment and risk factors were collected in the same way in five regions, to determine if important differences exist in rates of treatment between areas and whether this variation can be explained by differences in risk factors.
Section snippets
Methods
A detailed description of the methods used in the Global Longitudinal Study of Osteoporosis in Women (GLOW) study has been published [11]. In brief, GLOW is an observational cohort study conducted by 723 physicians in 17 local investigation centers in 10 countries (Australia, Belgium, Canada, France, Germany, Italy, Netherlands, Spain, UK, and USA).
Practices typical of each region were recruited through primary care networks organized for administrative, research or educational purposes, or by
Results
A total of 60,393 women participated in the baseline survey, representing a median response rate of 62% across all study sites [11]. There were 58,009 subjects with complete data for current use of AOM. Among all study sites, the lowest proportion of current use of an AOM was 16% in Northern Europe, and the highest was 32% in the USA and in Australia (Table 1). When treatment prevalence was stratified according to age ≥ 65 years with a prior hip or spine fracture, the highest proportions of women
Discussion
After adjusting for differences in risk factors for fracture in a large cohort of women in Europe and the USA, women in the US sites were almost three times as likely to be treated as women in the Northern European sites, and 1.5 times as likely to be treated as women in the Southern European sites. Women in Southern Europe were almost twice as likely to be treated as women in Northern Europe. Because the multivariable analyses adjust for the most significant risk factors for fracture,
Conclusions
These data on fracture risk factors and treatment in older women demonstrate that a substantial number of older women who may be at risk of future fractures are not receiving treatment to reduce that risk. In addition, important differences exist between the regions studied in the targeting of treatment towards women most at risk of fracture. Finally, the region in which a woman lives appears to be a stronger predictor of treatment than well-established risk factors. The reasons for such
Acknowledgments
The GLOW study is supported by a grant from The Alliance for Better Bone Health (Procter & Gamble Pharmaceuticals and sanofi-aventis) to The Center for Outcomes Research, University of Massachusetts Medical School. We thank the physicians and study coordinators participating in GLOW, the staff at the Center for Outcomes Research, Linda Chase for secretarial support, and Sophie Rushton-Smith, PhD, for coordinating revisions and providing editorial assistance including editing, checking content
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