Using Age, Bone Mineral Density, and Spine Fracture Status to Predict Fracture Risk

In a study using data from the Canadian Multicentre Osteoporosis Study (CaMos), Canadian researchers found that the most predictive risk factors for incident fracture were age, bone mineral density (BMD), and spine fracture status.
They used data from 2,761 patients who participated in CaMos.

In a study using the CaMos—a prospective study following a randomly selected, population-based community cohort of non-institutionalized men and women—those same researchers wanted to validate their previous analysis.  Therefore, they used data from patients who had incomplete spine radiograph assessments (1,447 women and 517 men) and who had been excluded from the previous analyses.

Their results appeared in the paper “Age, bone mineral density, and spine fracture status for predicting fracture risk,” which was presented at the 2011 Annual Meeting of the American Society of Bone and Mineral Research.

In the study, both prevalent and incident spine fractures were evaluated by quantitative morphometry of lateral spine radiographs at baseline—and then again at 5 years.

Researchers determined incident non-vertebral fractures by questionnaires that were mailed annually, with validation.

The endpoint for this study was a 5-year risk of an osteoporotic fracture defined as a morphometric vertebral fracture and/or a non-vertebral fragility fracture (a fracture with minimal trauma).

The research team found that results for the 1,964 patients were similar to the previously published results for the 2,761 patients in the CaMos.

A logistic regression model revealed a gradient of risk/standard deviation (GR/SD) of 1.88. The model recorded:

• age
• femoral neck BMD
• spine fracture status (yes/no)

This model captured almost all of the predictive information provided by a model with spine fracture status plus the World Health Organization (WHO) risk factors (GR/SD: 1.92). It also provided greater predictive information than a model that only took into account the WHO risk factors (GR/SD: 1.74).

Researchers found that fracture risk was markedly impacted by spine fracture status at all ages and BMD—including younger participants and those with a higher BMD.

In fact, they repeated all analyses for the overall population (n=4,725) and found that the results were very similar.

The study’s findings confirm that morphometric spine fracture status—along with age and BMD—predicted future fracture risk with greater simplicity and higher predictive accuracy than more complex models (including the WHO risk factors). Investigators determined that spine fracture status provides useful predictive information in regard to future fracture risk; they recommend a spine fracture status assessment in all patients who are at risk of fracture.