The effect of socioeconomic status on bone density testing in a public health-care system

Introduction and hypothesis An inverse relationship exists between socio-economic status (SES) and osteoporotic fractures. In publicly funded health-care systems there should be no barriers to accessing bone mineral density (BMD) testing, especially for those at increased fracture risk. Our hypothesis was that there would be a positive association between SES and BMD utilization (i.e. higher utilization rates in higher income women), resulting in disparities that disadvantage lower SES or lower income women. Methods A population-based BMD database from the Manitoba Bone Density Program was utilized to assess the association between SES (defined using income quintiles) and BMD utilization rates in women aged 50 years and older (n=107,944) for the 2001-2002 fiscal year. Analyses were stratified by age (50-64 years old and 65 years or older) and by a morbidity index obtained from the Johns Hopkins University Adjusted Clinical Group Case-Mix Adjustment System. Results Regression models demonstrated significantly higher BMD utilization rates among high SES women in all age and morbidity strata. Rate ratios varied from 1.76 (95% CI: 1.52-2.04) in 50- to 64-year-old women to 2.36 (95% CI: 1.60-3.49) in low morbidity women aged 65 or older. Conclusions Within the context of a publicly funded health-care system significant inverse associations are demonstrated between SES and BMD utilization rates. Further research is needed to better understand the nature of these associations and how they may contribute to health outcomes.