Pre-fracture individual characteristics associated with high total health care costs after hip fracture.

Older women with pre-fracture slow walk speed, high body mass index, and/or a high level of multimorbidity have significantly higher health care costs after hip fracture compared to those without those characteristics. Studies to investigate if targeted health care interventions for these individuals can reduce hip fracture costs are warranted. INTRODUCTION: The aim of this study is to estimate the associations of individual pre-fracture characteristics with total health care costs after hip fracture, using Study of Osteoporotic Fractures (SOF) cohort data linked to Medicare claims. METHODS: Our study population was 738 women age 70 and older enrolled in Medicare Fee for Service (FFS) who experienced an incident hip fracture between January 1, 1992 and December 31, 2009. We assessed pre-fracture individual characteristics at SOF study visits and estimated costs of hospitalizations, skilled nursing facility and inpatient rehabilitation stays, home health care visits, and outpatient utilization from Medicare FFS claims. We used generalized linear models to estimate the associations of predictor variables with total health care costs (2010 US dollars) after hip fracture. RESULTS: Median total health care costs for 1 year after hip fracture were $35,536 (inter-quartile range $24,830 to $50,903). Multivariable-adjusted total health care costs for 1 year after hip fracture were 14 % higher ($5256, 95 % CI $156 to $10,356) in those with walk speed <0.6 m/s compared to ≥1.0 m/s, 25 % higher ($9601, 95 % CI $3314 to $16,069) in those with body mass index ≥30 kg/m2 compared to 20 to 24.9 mg/kg2, and 21 % higher ($7936, 95 % CI $346 to $15,526) for those with seven or more compared to no comorbid medical conditions. CONCLUSIONS: Pre-fracture poor mobility, obesity, and multiple comorbidities are associated with higher total health care costs after hip fracture in older women. Studies to investigate if targeted health care interventions for these individuals can reduce the costs of hip fractures are warranted.

Magnitude and consequences of misclassification of incident hip fractures in large cohort studies: the Study of Osteoporotic Fractures and Medicare claims data.

UNLABELLED: In the Study of Osteoporotic Fractures (SOF), 18.5 % of incident hip fractures identified in Medicare Fee-for-Service claims data were not reported to or confirmed by the cohort. Cognitive impairment was a modest risk factor for false-negative hip fracture ascertainment via self-report. INTRODUCTION: Prospective cohort studies of fractures that rely on participant self-report to be the initial signal of an incident fracture could be prone to bias if a significant proportion of fractures are not self-reported. METHODS: We used data from the SOF merged with Medicare Fee-for-Service claims data to estimate the proportion of participants who had an incident hip fracture identified in Medicare claims that was either not self-reported or confirmed (by review of radiographic reports) in SOF. RESULTS: Between 1/1/1991 and 12/31/2007, 647 SOF participants had a hip fracture identified in Medicare claims, but 120 (18.5 %) were either not reported to or confirmed by the cohort. False-negative hip fracture ascertainment was associated with a reduced modified Mini-Mental State Exam (MMSE) score (odds ratio 1.31 per SD decrease, 95 % C.I. 1.06-1.63). Point estimates of associations of predictors of incident hip fracture were changed minimally when the misclassification of incident hip fracture status was corrected with use of claims data. CONCLUSIONS: A substantial minority of incident hip fractures were not reported to or confirmed in the SOF. Cognitive impairment was modestly associated with false-negative hip fracture ascertainment. While there was no evidence to suggest that misclassification of incident hip fracture status resulted in biased associations of potential predictors with hip fracture in this study, false-negative incident fracture ascertainment in smaller cohort studies with limited power may increase the risk of type 2 error (not finding significant associations of predictors with incident fractures).

25-Hydroxyvitamin D levels and cognitive performance and decline in elderly men.

OBJECTIVE: To test the hypothesis that lower 25-hydroxyvitamin D [25(OH)D] levels are associated with a greater likelihood of cognitive impairment and risk of cognitive decline. METHODS: We measured 25(OH)D and assessed cognitive function using the Modified Mini-Mental State Examination (3MS) and Trail Making Test Part B (Trails B) in a cohort of 1,604 men enrolled in the Osteoporotic Fractures in Men Study and followed them for an average of 4.6 years for changes in cognitive function. RESULTS: In a model adjusted for age, season, and site, men with lower 25(OH)D levels seemed to have a higher odds of cognitive impairment, but the test for trend did not reach significance (impairment by 3MS: odds ratio [OR] 1.84, 95% confidence interval [CI] 0.81-4.19 for quartile [Q] 1; 1.41, 0.61-3.28 for Q2; and 1.18, 0.50-2.81 for Q3, compared with Q4 [referent group; p trend = 0.12]; and impairment by Trails B: OR 1.66, 95% CI 0.98-2.82 for Q1; 0.96, 0.54-1.69 for Q2; and 1.30, 0.76-2.22 for Q3, compared with Q4 [p trend = 0.12]). Adjustment for age and education further attenuated the relationships. There was a trend for an independent association between lower 25(OH)D levels and odds of cognitive decline by 3MS performance (multivariable OR 1.41, 95% CI 0.89-2.23 for Q1; 1.28, 0.84-1.95 for Q2; and 1.06, 0.70-1.62 for Q3, compared with Q4 [p = 0.10]), but no association with cognitive decline by Trails B. CONCLUSION: We found little evidence of independent associations between lower 25-hydroxyvitamin D level and baseline global and executive cognitive function or incident cognitive decline.