Low physical activity and risk of falls among older adults in a high-altitude district of Peru: a secondary analysis of the Aunqui-Andes study

Background Falls are the second leading cause of unintentional injury deaths and disproportionately affect older adults, especially in low- and middle-income countries. In Peru’s high-Andean rural settings, hypobaric hypoxia, rugged terrain, and limited healthcare may increase the risk of falls. Low physical activity is associated with the risk of falls, yet evidence from high-altitude rural populations is scarce. This study aimed to estimate the association between low physical activity and risk of falls among older adults in a high-Andean district of Peru. Methods We conducted a secondary analysis of an analytical cross-sectional study (Aunqui-Andes) including 271 adults aged ≥ 60 years from Totos District, Ayacucho, Peru (3,286 m above sea level), enrolled in August 2022. Individuals with severe cognitive impairment or dependence for ambulation were excluded. Low physical activity was assessed using sex-specific cutoffs of the Physical Activity Scale for the Elderly (PASE), and risk of falls was defined as a Functional Reach Test distance < 20.32 cm. We fitted Poisson generalized linear models with a log link and robust variance to estimate adjusted prevalence ratios (aPRs) and 95% confidence intervals (95% CI), adjusting for sex, age group, marital status, educational level, comorbidities, and cognitive impairment. Results We analyzed 271 older adults (median age 75 years; 59.8% women). The proportion classified as at risk of falls was 57.2% ( n = 155), and the prevalence of low physical activity was 6.6% ( n = 18). In crude models, low physical activity was associated with a higher risk of falls (cPR = 1.62; 95% CI: 1.33–1.97; p < 0.001). In multivariable models adjusting for sex, age group, marital status, educational level, comorbidities, and cognitive impairment, the association persisted (aPR = 1.32; 95% CI: 1.09–1.62; p = 0.007). Conclusions Low physical activity was associated with a higher risk of falls among older adults living in a high-Andean district of Peru. These findings support incorporating practical screening for risk of falls using PASE and the Functional Reach Test, along with simple, locally adapted physical-activity support, into primary care and community programs in rural high-altitude areas and may inform public health actions to reduce fall-related harms in these underserved communities.