The social gradient of fractures at any skeletal site in men and women: data from the Geelong Osteoporosis Study Fracture Grid.

Abstract

Age-specific and age-standardized associations between socioeconomic status (SES) and fractures in adults showed a social gradient of fracture, irrespective of fracture site. Compared to the highest SES, males in the lowest SES group had a sixfold increased odds for any fracture, whilst females had a twofold increased odds. The effective identification of predisposing risk factors for fracture requires understanding any association with SES. These investigations should consider both sexes, span the adult age range and include any fractures. We investigated age- and sex-specific and age-standardized associations between SES and fractures at any skeletal site in Australians aged ≥ 50 years. Incident fractures that occurred 2006-2007 for adults aged ≥ 50 years were identified from radiological reports extracted for the Barwon Statistical Division, in south-eastern Australia. SES was determined by cross-referencing residential addresses with Australian Bureau of Statistics census data and then categorized in quintiles. We compared frequencies of observed vs. expected fractures for SES quintiles using χ (2) comparison, calculated age-specific fracture incidence across SES and compared age-standardized fracture rates in SES quintile 1 to quintile 5. We identified 3943 incident fractures (69.4 % female); 47.4 % had occurred at major osteoporotic fracture (MOF) sites (hip, humerus, spine and forearm/wrist). Differences existed in observed vs. expected fractures across SES quintiles (p ≤ 0.001, sexes combined); all fractures showed an inverse association with SES (p ≤ 0.001, sexes combined). Compared to the highest SES quintile, individuals from the lowest SES quintile had between two to six times greater standardized fracture rates. Disadvantaged men and women have an increased fracture incidence compared to their less disadvantaged counterparts. The large differences in fracture rates between SES groups warrant further research into designing appropriate, targeted interventions for those demographics at most risk.