Relationship Between Hip Fracture and New Onset of Cognitive Impairment Using the National Health and Aging Trends Study

BACKGROUND: Hip fractures are more common in persons with dementia, and there is likely a complex relationship with cognition. Hypothesizing that a fracture may precipitate cognitive decline, we (a) assessed the association between hip fracture and new onset of cognitive impairment and (b) described post-fracture cognitive trajectories in older adults. METHODS: This retrospective analysis included Medicare beneficiaries aged 65 years and older from the 2011 cohort of the National Health and Aging Trends Study (NHATS). Participants who sustained a hip fracture and had pre-fracture normal cognition were identified from survey rounds 2-13. The cognitive outcome was identified using the NHATS dementia classification (no, possible, or probable dementia). We matched a hip fracture case with up to five controls using propensity scores and examined the association between hip fracture and onset of cognitive impairment using logistic regression in the matched sample. We additionally described 3-year patterns of cognition after hip fracture in a subsample with extended follow-up. RESULTS: The matched sample included 169 participants with a hip fracture and 798 controls (20.7% and 17.0% onset of possible/probable dementia, respectively). There was no significant association between hip fracture and onset of possible/probable dementia (OR: 1.27, 95% CI: 0.74-2.20, p = 0.39) or probable dementia (OR: 1.88, 95% CI: 0.84-4.20; p = 0.12). CONCLUSIONS: We were unable to detect a significant association between a hip fracture and new onset of cognitive impairment in older adults. However, conclusions are limited by large confidence intervals. There was a signal toward a positive association, particularly for probable dementia. Future research should be performed in larger sample sizes with rigorous matching to understand risk factors for developing cognitive impairment after hip fracture.