Background Fractures have been associated with subsequent increases in mortality, but it is unknown how long that increase persists. Methods 5580 women from a large community-based multicenter US prospective cohort of 9704 (Study of Osteoporotic Fractures) were followed prospectively for almost 20 years. We age-matched 1116 hip fracture cases with four controls (n=4464). To examine the effect of health status, we examined a healthy older subset (n=960) aged 80+ who attended the 10-year follow-up examination, and reported good/excellent health. Incident hip fractures were adjudicated from radiology reports by study physicians. Death was confirmed by death certificates. Results Hip fracture cases had two-fold increased mortality in the year after fracture compared to controls [16.9% vs. 8.4%; Odds Ratio (OR)=2.4; 95% Confidence Interval (CI) 1.9, 3.1]. When examined by age and health status, short-term mortality was increased in those aged 65 to 70 (16.3% vs 3.7%; OR=5.0; 2.6, 9.5), aged 70 to 79 (16.5% vs 8.9%; OR=2.4; 1.8, 3.3), and only in aged 80+ with good/excellent health (15.1% vs. 7.2%; OR=2.8; 1.5, 5.2). After the first year, survival of hip fracture cases and controls was similar except in those aged 65 to 70 who continued to have increased mortality. Conclusions Short-term mortality is increased after hip fracture in women aged 65 to 79 and in exceptionally healthy women 80 or older. Women 70 and older return to previous risk levels after a year. Interventions are needed to decrease mortality in the year after hip fracture, when mortality risk is highest.

II.

Whether nulliparity increases fracture risk is unclear from prior studies, which are limited by small samples or lack of measured bone mineral density. No study has evaluated whether the effect of parity differs by skeletal site. We prospectively analyzed the relationship of parity to the risk of incident nontraumatic hip, spine, and wrist fractures in 9704 women aged 65 years or older participating in the Study of Osteoporotic Fractures to determine if parity reduces postmenopausal fracture risk, and if so, if this risk reduction is (1) greater at weight-bearing skeletal sites and (2) independent of bone mineral density. Parity was ascertained by self-report. Incident hip and wrist fractures were determined by physician adjudication of radiology reports (mean follow-up, 9.8 years) and spine fractures by morphometric criteria on serial radiographs. The relationship of parity to hip and wrist fracture was assessed by proportional hazards models. Spine fracture risk was evaluated by logistic regression. Compared with parous women, nulliparous women (n ‫؍‬ 1835, 19%) had an increased risk of hip and spine, but not wrist, fractures. In multivariate models, parity remained a significant predictor only for hip fracture. Nulliparous women had a 44% increased risk of hip fractures independent of hip bone mineral density (hazards ratio, 1.44; 95% CI, 1.17-1.78). Among parous women, each additional birth reduced hip fracture risk by 9% (p ‫؍‬ 0.03). Additionally, there were no differences in mean total hip, spine, or radial bone mineral density values between nulliparous and parous women after multivariate adjustment. In conclusion, childbearing reduces hip fracture risk by means that may be independent of hip bone mineral density. (J Bone Miner Res 2003;18:893-899)