Rationale and design of an ancillary study evaluating the effects of the cocoa flavanol and/or multivitamin interventions on falls and physical performance outcomes in the COcoa Supplement and Multivitamin Outcomes Study (COSMOS)

Background: Falls and decreased physical function increase markedly with age and result in injury, hospitalization, and premature death. Emerging studies show potential benefits of supplemental cocoa extract on physical performance, including grip strength and walking speed in older adults. However, there are no large, long-term randomized controlled trials of effects of supplemental cocoa extract on falls, muscle performance, and/or fallrelated injuries. Methods: The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is a double-blind, placebocontrolled, 2 x 2 factorial trial investigating effects of supplementation with cocoa extract (500 mg/d, including 80 mg (-)-epicatechin) and/or a multivitamin on prevention of cardiovascular disease and cancer in 21,442 women (>= 65 years) and men (>= 60 years). COSMOS: Effects on Falls and Physical Performance is an ancillary study to COSMOS that will clarify effects of cocoa extract and/or multivitamin supplementation on falls, physical performance, and incident fracture outcomes in older adults. Injurious fall(s) resulting in healthcare utilization and recurrent falls were regularly assessed by follow-up questionnaires in the overall cohort. Incident fractures were also assessed by annual questionnaires. Circumstances surrounding falls and any fall-related injuries will be confirmed by medical record review. Effects of the interventions on 2-year changes in physical performance measures (grip strength, walking speed, and the Short Physical Performance Battery) will be tested in a clinic sub-cohort (n = 603). Conclusion: Results from this ancillary study will determine whether supplemental cocoa extract slows agerelated declines in physical performance and decrease injurious and recurrent falls and fall-related injuries and fractures that are major public health problems in older adults.