Incidence of hip and other osteoporotic fractures in elderly men and women: Dubbo Osteoporosis Epidemiology Study.

Abstract

In this prospective 12-year study in men and women 60 years of age and older, there was a 4-6% per year reduction in the incidence rate of overall osteoporotic fractures, but the study was unable to exclude any change in the hip fracture incidence rate. Approximately one-half of hip fractures occurred before 80 years in men and two-thirds before 85 years in women. The age distribution of hip fractures underlines the need for earlier intervention in osteoporosis. Although hip fracture is the major osteoporotic fracture in terms of health outcomes, quality of life, and costs, there is a paucity of long-term data on secular changes in men and women within a defined community. This long-term prospective population-based study over 12 years from 1989 to 2000 specifically examined the age distribution and secular changes in the incidence rates of hip and other osteoporotic fractures in men and women 60 years of age and older in a predominantly white population in Dubbo, Australia. Hip and all other clinical fractures were ascertained by reviewing all radiography reports from the two area radiology services, ensuring complete ascertainment of all clinical osteoporotic fractures. Among the 1055 symptomatic atraumatic fractures (after excluding pathological fractures), there was a significant reduction in the overall fracture incidence rate in women (4% per year; p = 0.0003) and men (6% per year; p = 0.0004) over the 12 years. There were 229 hip fractures (175 in women and 54 in men) within 39,357 person-years of observation. The overall rate +/- SE of hip fracture was 759 +/- 57 per 100,000 person-years in women and 329 +/- 45 per 100,000 person-years in men, with an exponential increase with age. With advancing age, the incidence rate of hip fractures in men approached that in women; the female:male ratio fell from 4.5 (95% CI: 1.3-15.7) to 1.5 (0.9-2.5) and 1.9 (1.2-2.8) in the 60-69, 70-79, and 80+ year age groups, respectively. In women, the absolute number of fractures and incidence rate continuously increased with age; however, in men, the absolute number of hip fractures peaked at 80-84 years of age and then decreased. Most importantly, despite the continuing increase with age, almost one-half (48%) of the hip fractures occurred before the age of 80 years in men, and 66% of hip fractures occurred before the age of 85 years in women. The overall hip fracture incidence is comparable with other white (except Sweden) and Asian groups as well as two other Australian studies. This study could not exclude a change in hip fracture incidence rate, even in those 80 years of age and over among whom the incidence of hip fractures was the highest. The incidence data highlight the fact that a large proportion of hip fractures occurs in those under 80 years of age, particularly in men. This age distribution underlines the need for earlier intervention in osteoporosis in women and particularly in men to achieve the most cost-effective outcomes.