Physical Activity and Different Concepts of Fall Risk Estimation in Older People--Results of the ActiFE-Ulm Study.

Jochen Klenk,Richard Peter,Michael Dieter Denkinger,Clemens Becker,Thorsten Nikolaus,Kilian Rapp,Ngaire Kerse,Dietrich Rothenbacher,Stephen D Ginsberg

doi:10.1371/journal.pone.0129098

Abstract

ObjectivesTo investigate the relationship between physical activity and two measures of fall incidence in an elderly population using person-years as well as hours walked as denominators and to compare these two approaches.DesignProspective cohort study with one-year follow-up of falls using fall calendars. Physical activity was defined as walking duration and recorded at baseline over one week using a thigh-worn uni-axial accelerometer (activPAL; PAL Technologies, Glasgow, Scotland). Average daily physical activity was extracted from these data and categorized in low (0–59 min), medium (60–119 min) and high (120 min and more) activity.SettingThe ActiFE Ulm study located in Ulm and adjacent regions in Southern Germany.Participants1,214 community-dwelling older people (≥65 years, 56.4% men).MeasurementsNegative-binomial regression models were used to calculate fall rates and incidence rate ratios for each activity category each with using (1) person-years and (2) hours walked as denominators stratified by gender, age group, fall history, and walking speed. All analyses were adjusted either for gender, age, or both.ResultsNo statistically significant association was seen between falls per person-year and average daily physical activity. However, when looking at falls per 100 hours walked, those who were low active sustained more falls per hours walked. The highest incidence rates of falls were seen in low-active persons with slow walking speed (0.57 (95% confidence interval (95% CI): 0.33 to 0.98) falls per 100 hours walked) or history of falls (0.60 (95% CI: 0.36 to 0.99) falls per 100 hours walked).ConclusionFalls per hours walked is a relevant and sensitive outcome measure. It complements the concept of incidence per person years, and gives an additional perspective on falls in community-dwelling older people.

Highlights

Falls are a major cause of injury and disability in older people and can result in serious health and social consequences such as fractures, poor quality of life, loss of independence, and nursing home admission [1,2]
No statistically significant association was seen between falls per person-year and average daily physical activity
The highest incidence rates of falls were seen in low-active persons with slow walking speed (0.57 (95% confidence interval: 0.33 to 0.98) falls per 100 hours walked) or history of falls (0.60 falls per 100 hours walked)

Summary

Introduction

Falls are a major cause of injury and disability in older people and can result in serious health and social consequences such as fractures, poor quality of life, loss of independence, and nursing home admission [1,2]. In communitydwelling older populations about one out of 3 persons fall each year, half of them being recurrent fallers [3,4]. Lower limb and balance problems are strong risk factors for falls [6]. Frequent physical activity (PA) is recommended to reduce health risks like cardiovascular disease and diabetes, and to reduce falls [8] and is a major target in the International Classification of Functioning, Disability and Health (ICF) framework to maintain or improve social participation and independent living

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Methods

Conclusion