LAUSR

BACKGROUND We examined regional variation in falls in a geographically diverse cohort of older people with HIV (PWH), and explored whether physical activity, sex, or BMI modified these associations. SETTING PWH enrolled in ACTG A5322 HAILO (HIV Infection, Aging and Immune Function Long-Term Observational Study). METHODS Participants who reported falls in the 6 months prior to each semiannual visit with ≥1 consecutive pair of falls assessments were included. We examined associations between geographic region with recurrent falls (≥2) over each 12-month period using repeated measures multinomial logistic regression models, and assessed effect modification by adding an interaction term between geographic region and each potential effect modifier. RESULTS A total of 788 men and 192 women with median age at study entry of 51 years contributed up to 240 weeks of data. U.S. region included Northeast (22%), Midwest (29%), South (20%), and West (29%). In multivariable analyses, compared to Western region, greater risk was seen among Midwestern region (OR=2.35[95% CI=1.29,4.28]) and Southern region (2.09[1.09,4.01]). Among those with higher physical activity, Midwestern region had higher odds of recurrent falls than Western region. Among obese individuals, Southern region had higher odds of recurrent falls than Western region. Sex did not modify the association between region and recurrent falls. CONCLUSION Fall risk varied by geographic region and associations between geographic region and recurrent falls appeared to be modified by physical activity and obesity. This may help identify subgroups of older PWH for targeted falls screening/interventions.