BackgroundFall prevention recommendations include mobility or balance testing to identify older adults with high fall risk who require further intervention. However, there is no consensus on the best tests or optimal cut-off values. The Initial Test for Fall RIsk Assessment in The Elderly (INITIATE) study was designed to determine the optimal screening test(s) for predicting falls among community-dwelling older adults. Here we describe the study protocol, sample characteristics, and baseline differences between participants with and without a history of falling.MethodsWe undertook a 1-year prospective cohort study of community-dwelling older adults (≥ 65 years) able to walk 10 m without assistance at baseline and living in Ontario, Canada. Participants underwent a 2-hour baseline visit where 7 validated balance and mobility tests (Timed up and go (TUG) usual pace, TUG fast pace, TUG with a cognitive dual task, Brief Balance Evaluation Systems Test (BESTest), 5 times sit-to-stand (5TSTS), single leg stance, gait speed) were administered. Falls were tracked for 12 months using monthly diaries and follow-up calls for context. Participants received quarterly calls to monitor general wellbeing, healthcare utilization, and changes to mobility. Descriptive statistics were calculated and differences by 12-month fall history were tested using t-tests, chi square tests, and Wilcox Rank Sum tests as appropriate.ResultsFrom 3211 contacted older adults, 514 (19%) consented. The mean age was 76.4 years (SD 6.7), 64% were female, 68% had a postsecondary degree/diploma, and 231(45%) reported a fall in the last 12 months. Means(SD) for the performance-based tests were as follows: TUG = 11.8s(4.0), TUG fast pace = 9.2s(3.4), TUG cog = 14.2s(5.9), Brief BESTest = 15.9 score(5.3), 5TSTS = 12.5s(4.3), single leg stance = 14.1s(16.3), gait speed = 1.14 m/s(0.28). Comparisons between baseline fallers and non-fallers showed no differences in age, sex, income, or education(p > 0.05) but did show differences in all 7 tests(p < 0.05).ConclusionsParticipants are representative of community-dwelling older adults with fall risk. Balance and mobility test differences between fallers and non-fallers support the need for prospective comparisons of their predictive validity. Follow-up results, expected in late 2025, will help inform future updates to fall risk assessment and prevention guidelines.