Fear of Falling, Falls, and Gait Variability in Older Community‐Dwelling Individuals: Is There an Association?

To the Editor: Fear of falling (FOF) is defined as the lack of self-confidence that activities daily living may be performed without falling.1 Its prevalence ranges from 21% to 85% and is greater with older age, a history of falls and in women.1-3 Changes in gait have been associated with FOF and are usually classified as highest-level gait disorders related to cortical gait control impairments.4-7 A limited number of studies have examined the association between high stride time variability (STV), which is a biomarker of cortical gait impairment, and FOF.3-7 These studies had mixed results, with some reporting an association and others not. Divergences previously reported on the association between high STV and FOF may be related to the effect of confounders such as the history of falls, age, and sex. The aims of the current study were to compare STV of older community-dwelling individuals with and without FOF and falls, and to examine the association between STV and FOF while taking into account the effect of these potential confounders. Between January 2011 and April 2012, 1,106 community-dwelling individuals (mean age 70.4 ± 4.7; 49.1% female) were recruited in the French health examination center (HEC) of Lyon, France, and included in this cross-sectional study. The inclusion criterion was aged 65 and older. FOF was assessed using a single question: “Are you afraid of falling?” History of falls over the past year was recorded using a standardized questionnaire. A fall was defined as unintentionally coming to rest on the ground, floor, or other lower level. Fallers were defined according to the occurrence of at least one fall during the past year. STV was measured at steady-state self-selected walking speed on an electronic walkway (GaitRite, CIR Systems, Sparta, NJ or SMTEC, Sport & Medical Technologies SA, Nyon, Switzerland) in a 6-m corridor. It has been previously shown that the level of agreement between these two systems was high, confirming that they both provide a similar measure of STV.8 Age and sex were also recorded. Participants were separated into four groups: no FOF and no falls, no FOF and falls, FOF and no falls, FOF and falls. Between-group comparisons were performed using one-way analysis of variance with Bonferroni corrections or the chi-square test, as appropriate. Multiple linear regression analysis was performed to specify the association between STV (dependent variable) and the presence of FOF and falls (independent variables) adjusted for participant characteristics (age and sex). P < .05 was considered statistically significant. All analyses were performed using SPSS version 19.0 (SPSS, Inc., Chicago, IL). Of 1,106 included participants, 58.6% (n = 648) were nonfallers without FOF, 20.3% (n = 225) nonfallers with FOF, 10.0% (n = 110) fallers without FOF, and 11.1% (n = 123) fallers with FOF. As shown in Table 1, STV was significantly higher in fallers with FOF than in nonfallers without FOF (P = .03). In participants with FOF, those without (P = .02) and with (P = .03) a history of previous falls were older than nonfallers without FOF. Participants with FOF were more likely to be female than those without (P < .003), regardless of history of previous falls. The fully adjusted linear regression models highlighted that high STV was associated with FOF with falls (β = 0.011, 95% confident interval (CI) = 0.003–0.019, P = .009) and age (β = 0.001, 95% CI = 0.000–0.001, P = .001). No association was shown between no FOF with falls (β = –0.002, 95% CI = −0.006–0.006, P > .99) and FOF without falls (β = 0.003, 95% CI = −0.006–0.011, P = .55). These findings show that only age and FOF with falls were positively associated with a high STV. These findings may explain in part divergences previously reported. As shown previously,6 the current study confirms that FOF alone (without falls) is not related to greater gait variability, suggesting that cortical gait control impairment related to FOF is more complex than expected and requires additional disorders such as falls to induce significant changes in gait control. In contrast with previous publications,6, 9 the current study did not find an association between high gait variability and falls. One explanation may be based on the high level of functioning of the studied sample of older adults, who were all community-dwelling. In addition, the significant age-related increase in STV is in concordance with previous literature.9 Further studies are needed to corroborate and explain these findings. We are grateful to the participants for their cooperation. The authors would like also to thank C. Nitenberg from the Health Examination Center of Lyon, France, and B. Bongue, A. Colvez, and N. Deville from Health Examination Center of Saint-Etienne, France. Conflict of Interest: Prof. Beauchet has served as an unpaid consultant for Ipsen Pharma company and serves as an associate editor for Gériatrie, Psychologie et Neuropsychiatrie du Vieillissement. He has no relevant financial interest in this manuscript. Dr. Annweiler has served as an unpaid consultant for Ipsen Pharma company and serves as an associate editor for Gériatrie, Psychologie et Neuropsychiatrie du Vieillissement and for the Journal of Alzheimer's Disease. He has no relevant financial interest in this manuscript.