Regional Differences in Risk of Recurrent Falls Among Older U.S. Women and Men with HIV in the HIV Infection, Aging, and Immune Function Long-Term Observational Study

Geographic location was a strong predictor of falls among women with and without HIV in the Women's Interagency HIV Study. We examined regional variation in falls in a more geographically diverse cohort of older people with HIV (PWH) and explored whether physical activity, sex, or body-mass index modified these associations. PWH enrolled in the A5322 HAILO (HIV Infection, Aging, and Immune Function Long-Term Observational Study). Participants who reported falls in the 6 months before each semiannual visit and had ≥1 consecutive pair of fall assessments were included. We examined associations of geographic region [Northeast, Midwest, South, and West] 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. A total of 788 men and 192 women with median age of 51 years at study entry contributed up to 240 weeks of data. U.S. regions included Northeast (22%), Midwest (29%), South (20%), and West (28%). In multivariable analyses, compared with the Western region, greater risk was seen among Midwestern (odds ratio [OR] = 2.35 [95% confidence interval (CI) = 1.29-4.28]) and Southern regions (OR = 2.09 [95% CI = 1.09-4.01]). Among those with higher physical activity, the Midwestern region had higher odds of recurrent falls than the Western region. Among obese individuals, the Southern region had higher odds of recurrent falls than the Western region. Sex did not modify the association between region and recurrent falls. Among older PWH, fall risk varied by geographic region. 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 fall screening/interventions.