Hyperkyphosis and incident falls among community-dwelling older adults

Background: Falls are a common cause of morbidity among older adults. Although many fall risk factors are well understood, it is unknown whether a common geriatric condition, hyperkyphosis, increases fall risk. Objectives: This dissertation research sought to determine whether older persons with worse degrees of kyphosis may be at increased risk of falls. Methods: Three longitudinal cohorts of older adults (aged ≥65) were used, each with different kyphosis measures, to examine the association between degree of kyphosis and fall risk. Study 1 examined whether four measures of kyphosis (Debrunner kyphometer, flexicurve ruler, Cobb angle, and block method) increased the odds of an incident fall over one year of monthly falls follow-up in a mixed-gender sample of 72 individuals (mean age=78). Studies 2 and 3 each prospectively examined two different measures of kyphosis and incident falls over three years of tri-annual follow-up through multivariable modeling with GEEs. Study 2 included 2,346 men with the Cobb angle measure of kyphosis (mean age=74) and 2,929 men with block-measured kyphosis (mean age=79) from the Osteoporotic Fractures in Men Study (MrOS). Study 3 used data from 1,162 women with the Cobb angle measure (mean age=69) and 610 women with the flexicurve measure of kyphosis (mean age=73) from the Study of Osteoporotic Fractures in Women (SOF). Results: In Study 1, all four measures of kyphosis conferred a 2-3 fold increase per SD in the odds of a fall over the following year (64% of participants fell over one year). In Studies 2 and 3, Cobb angle was not associated with fall risk in either MrOS or SOF. The blocks method was predictive of fall risk in MrOS (RR=1.11 per SD; 95% CI=1.06, 1.17) and KI was predictive of fall risk in SOF (RR=1.22 per SD; 95% CI=1.07, 1.40).Conclusion: All three studies provide evidence that increased kyphosis predicts greater fall risk in older persons. The Cobb angle measure, however, appears to be least related to falls, possibl