FEAR OF FALLING IS FREQUENT among communitydwelling

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1 291 ORIGINAL ARTICLE Validation of an Adapted Falls Efficacy Scale in Older Rehabilitation Patients Christophe J. Büla, MD, Estelle Martin, PhD, Stéphane Rochat, MD, Chantal Piot-Ziegler, PhD ABSTRACT. Büla CJ, Martin E, Rochat S, Piot-Ziegler C. Validation of an adapted Falls Efficacy Scale in older rehabilitation patients. Arch Phys Med Rehabil 2008;89: Objective: To determine the psychometric properties of an adapted version of the Falls Efficacy Scale (FES) in older rehabilitation patients. Design: Cross-sectional survey. Setting: Postacute rehabilitation facility in Switzerland. Participants: Seventy elderly persons aged 65 years and older receiving postacute, inpatient rehabilitation. Interventions: Not applicable. Main Outcome Measures: FES questions asked about subject s confidence (range, 0 [none] 10 [full]) in performing 12 activities of daily living (ADLs) without falling. Construct validity was assessed using correlation with measures of physical (basic ADLs [BADLs]), cognitive (Mini-Mental State Examination [MMSE]), affective (15-item Geriatric Depression Scale [GDS]), and mobility (Performance Oriented Mobility Assessment [POMA]) performance. Predictive validity was assessed using the length of rehabilitation stay as the outcome. To determine test-retest reliability, FES administration was repeated in a random subsample (n 20) within 72 hours. Results: FES scores ranged from 10 to 120 (mean, ). Internal consistency was optimal (Cronbach.90), and item-to-total correlations were all significant, ranging from.56 (toilet use) to.82 (reaching into closets). Test-retest reliability was high (intraclass correlation coefficient,.97; 95% confidence interval,.95.99; P.001). Subjects reporting a fall in the previous year had lower FES scores than nonfallers ( vs , P.054). The FES correlated with POMA (Spearman.40, P.001), MMSE (.37, P.001), BADL (.43, P.001), and GDS (.53, P.001) scores. These relationships remained significant in multivariable analysis for BADLs and GDS, confirming FES construct validity. There was a significant inverse relationship between FES score and the length of rehabilitation stay, independent of sociodemographic, functional, cognitive, and fall status. Conclusions: This adapted FES is reliable and valid in older patients undergoing postacute rehabilitation. The independent association between poor falls efficacy and increased length of stay has not been previously described and needs further investigations. From the Service of Geriatric Medicine and Geriatric Rehabilitation, Department of Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland (Büla, Martin, Rochat); and Health Psychology, Institute of Psychology, University of Lausanne, Lausanne, Switzerland (Piot-Ziegler). Supported in part by the Swiss National Scientific Foundation (grant no. 3252BO ) and the Leenaards Foundation. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated. Reprint requests to Christophe J. Büla, MD, CUTR Sylvana, Ch de Sylvana 10, 1066 Epalinges, Switzerland, christophe.bula@chuv.ch /08/ $34.00/0 doi: /j.apmr Key Words: Accidental falls; Fear; Rehabilitation by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation FEAR OF FALLING IS FREQUENT among communitydwelling elderly persons, with prevalence ranging from 25% up to 50%. 1-9 In these persons, fear of falling has been associated with activity restriction, functional decline, decreased quality of life, and institutionalization, 1-11 making it a potential target for specific intervention. Several approaches have been used to investigate fear of falling, ranging from a single question asking about being afraid of falling to more complex scales inquiring about selfperceived confidence in performing various activities without falling. 4,12-15 Although both measures are highly correlated, measures of falls efficacy were found in some studies to have stronger association with functional status than a single question, 7,9 suggesting they might be different, albeit complementary measures. The Falls Efficacy Scale (FES) was developed by Tinetti et al 4 to assess the confidence a person has in performing several activities of daily living (ADLs) without falling. Initially validated in a sample of community-dwelling elderly persons, this scale was shown to be reliable and to have construct as well as predictive validity in subsequent studies of similar populations. 2,4,9 Moreover, it was shown to be sensitive to change after interventions, 16 making falls efficacy a potential important clinical endpoint for rehabilitation. Surprisingly, none of the instruments developed to assess falls efficacy have been formally validated in older patients undergoing postacute rehabilitation, 15 despite the high likelihood of these patients experiencing poor falls self-efficacy. 17 It is therefore unclear whether these instruments will maintain their psychometric properties in this population. In addition, some authors 12,18 mentioned their concern about a potential ceiling effect when using the FES to assess older persons with higher function. Older patients admitted to postacute rehabilitation have very heterogeneous levels of function. It is also unclear what is the best set of activities to include to avoid the ceiling or floor effect when assessing this population. The aim of this study was to determine the psychometric properties of an adapted version of the FES in a sample of older patients admitted to postacute care rehabilitation. The specific objectives were to determine the internal consistency, intraobserver test-retest reliability, construct, and predictive validity of the FES. Construct validity was assessed by testing the hypotheses that the FES score would be lower in fallers compared with nonfallers; would be positively correlated with measures of functional, physical, and mobility performance; and would be negatively correlated with depressive symptoms. For predictive validity, the hypothesis was that the FES would be inversely correlated with the rehabilitation length of stay (LOS).

2 292 FALLS EFFICACY IN REHABILITATION, Büla Table 1: Content of the FES in Order of Presentation and Item-to- Total Correlation Coefficients Item METHODS Item-to-Total Correlation Coefficient* Reaching into cabinets or closets.82 Preparing simple meals.81 Getting in and out of a chair.65 Answering door, getting to the phone.64 Taking a bath or shower.70 Getting on and off the toilet.56 Getting dressed and undressed.74 Getting in and out of bed.63 Going up and down the stairs.65 Doing light housekeeping (eg, making bed, dust).74 Walking around the house.82 Simple shopping.76 *All P.001. Study Population and Setting Participants were consecutive patients aged 65 years and over admitted to a postacute rehabilitation facility. Subjects were not eligible if they had significant cognitive impairment, defined as a score lower than 20 on the Mini-Mental State Examination (MMSE), 19 or significant depressive symptoms, defined as a score of 6 or more on the 15-item Geriatric Depression Scale (GDS). 20 A sample size of 70 persons was selected to perform multivariate analysis with potential sociodemographic and functional covariates, but no formal samplesize calculation was performed. The study was approved by the institutional review board. Oral informed consent for participation was obtained from each participant. Data Collection Data were collected through face-to-face interviews by a research assistant within 72 hours after admission. Data included demographics, living arrangement, previous falls within the last 6 months, self-reported performance in basic ADLs (BADLs), using Katz s instrument, 21 and instrumental ADLs (IADLs), using Lawton s instrument. 22 Observed performance in BADLs was collected from the nursing charts. For each activity, patients were considered dependent if unable to perform the task without assistance. Cognitive status and affective status were assessed using MMSE 19 and 15-item GDS 20 scales, respectively. Gait and balance performance was assessed using the Performance Oriented Mobility Assessment (POMA) scale. 23 Assessment of Falls Efficacy A translated and adapted version of the FES 4 was used to assess falls self-efficacy. A translation back-translation process from English to French to English was performed, including cultural adaptation for some items (eg, walking around the house rather than around the block). The adapted version includes 12 ADLs (table 1) because 2 outdoor activities (walking around one s house, simple shopping) were added to the original scale to include more demanding activities when investigating populations with a wider range of functional abilities. These 2 activities were selected from the list of activities initially considered when the FES was developed. 4 As in the revised FES format, 9 participants were asked to rank on a 0 (no confidence) to 10 (full confidence) scale their confidence in performing these activities without falling. The research assistant read the questions out to the participants who had the FES in written format in front of them. In case they were not able to perform the activity, participants were asked to indicate their level of confidence if performing the task. Participants were prompted to provide a hypothetical rating by asking them to estimate how much fear of a fall was responsible for not performing the task. Test-retest reliability was assessed in a random subsample of 20 elderly participants by repeating the FES within 72 hours of the first interview. Statistical Analysis Characteristics of subjects were described using descriptive statistics. Internal consistency of the FES was assessed using the Pearson coefficient from interitem and item-to-total correlation analyses. Internal reliability was assessed using Cronbach coefficient. Test-retest reliability was assessed by intraclass correlation coefficient (ICC) between FES scores at test and retest 72 hours later, using analysis of variance. 24 Factor analysis was performed to study the structure of the scale, using principal component analysis with varimax rotation. Construct validity was assessed using the Pearson coefficient from correlation analyses with continuous variables such as GDS, MMSE, POMA, and BADL scores. Stepwise multivariable linear regression analyses were performed to (1) identify participants characteristics that were independent predictors of FES score and (2) determine the association between FES score and rehabilitation LOS. To be included in the multivariable models, variables had to show a statistically significant association in bivariate analysis. Because some variables were highly correlated (eg, preadmission BADLs and IADLs, admission BADLs, MMSE), the a priori decision was to preferentially include in the initial model variables that resulted from objective rather than self-reported measures (eg, nurse-observed BADL performance on admission rather than self-reported BADL before hospitalization). Covariates included in the multivariate models were age, sex, BADL, GDS, MMSE, and POMA scores to predict FES score and age, living situation (living alone or not), BADL, MMSE, and fall status to predict LOS. The significance levels to enter and to remain in the models were set at 0.1 and 0.2, respectively. Compatibility with the regression assumptions was checked for both models. Stability of the models were further assessed using bootstrapping methods. 25 Statistical analyses were performed by using Stata. a RESULTS Characteristics of the study population are shown in table 2. Overall, participants had a wide range of age and functional and mobility performance. Almost two thirds reported a fall in the previous year, including 14% who were admitted after a hip fracture. FES administration took a median of 4 minutes 10 seconds (range, 1min 20s 11min 30s). Scores ranged from 10 to 120 (mean, ; median, 93). Scale Reliability and Structure The scale s internal consistency was optimal (Cronbach.90), with interitem correlations ranging from.19 to.80. Item-to-total correlations (see table 1) were all significant, ranging from.56 (toilet use) to.82 (reaching into closets), and test-retest reliability was high (ICC.97; 95% confidence interval [CI],.95.99; P.001). Factor analysis suggested a 2-factor solution, accounting for 63.7% of the sample variance. A first rotated factor explained

3 FALLS EFFICACY IN REHABILITATION, Büla 293 Table 2: Baseline Characteristics of the Total Population (N 70) Characteristics Values Age (y) (65 99) Women 65.7 Living alone 63.2 In-home help before hospitalization 56.1 Fall in the previous year 61.4 Admitted after hip fracture 14.0 BADL score before admission* (4 6) IADL score before admission (1 8) BADL score at admission (1 6) MMSE score (20 30) MMSE score GDS score (0 5) POMA score (10 28) FES score (10 120) NOTE. Values are mean standard deviation (range) or percent. *Includes bathing, dressing, using the toilet, transferring between bed and chair, maintaining continence, and feeding. Scores range from 0 to 6, with higher scores indicating higher function. 21 Includes using the phone, grocery shopping, cooking, housekeeping, doing the laundry, using transportation, taking medications, and handling finances. Scores range from 0 to 8, with higher scores indicating higher function. 22 Scores range from 0 to 30, with scores below 24, suggesting the presence of cognitive impairment. 19 Scores range from 0 to 15, with higher scores indicating more depressive symptoms. 20 Scores range from 0 to 28, with higher scores indicating better gait and balance performance. 23 Scores range from 0 to 120, with higher scores indicating higher confidence. 32.8% of the variance and loaded mostly on outdoor activities (eg, walking around the house, simple shopping), whereas the second factor (explaining 30.9% of the variance) loaded mostly on indoor activities related to BADLs (eg, transferring in or out of bed, getting on or off the toilet, getting dressed or undressed). Construct Validity Comparisons of FES score between subjects reporting a fall in the previous 12-month period or not showed that the former tended to have lower self-efficacy than the latter ( vs , P.054). Of note, a difference in FES scores became clearly significant when excluding a patient who scored 10 on the FES and had significant cognitive impairment (MMSE score, 22/30) and balance impairment (POMA score, 22/28) but reported no previous fall. Other analyses showed that the FES correlated significantly with measures of gait and balance (Spearman.40, P.001), affective status (.53, P.001), and observed performance in BADLs at admission (.43, P.001) (fig 1). Additional significant correlations were observed with cognitive performance (MMSE,.37, P.001) and self-reported performance in IADLs before hospital admission (.32, P.006). In multivariable linear regression analysis, the FES total score remained significantly associated (adjusted R 2.47) with affective status, observed BADL performance, age, and female sex (table 3). Predictive Validity Finally, participants LOS in rehabilitation ranged from 2 to 49 days (median, 20d; mean, d) and correlated inversely with FES score (.51, P.001) (fig 2). This relationship remained significant in multivariable analysis that controlled for observed performance in BADLs, cognition, and fall status (adjusted R 2.42,.09; 95% CI,.17 to.01; P.032) (table 4). At the end of rehabilitation, only 5 patients (5/70 [7.1%]) did not return to their home and were transferred to the acute hospital (1 elective and 1 emergency transfer) and to nursing A B C POMA score GDS score FES score FES score BADL score (performance at the time of assessment) FES score Fig 1. Relationships between FES scores (range, 0 120; higher scores indicate higher confidence) and (A) POMA scores (range, 0 28; higher scores indicate better gait and balance), (B) GDS scores (range, 0 15; higher scores indicate more depressive symptoms), and (C) performance in BADLs (range, 0 6; higher scores indicate higher independence). Shaded areas correspond to the 95% CIs around regression line.

4 294 FALLS EFFICACY IN REHABILITATION, Büla Table 3: Results of the Multivariate Analysis Predicting FES Score Characteristics SE 95% CI P GDS score to BADL score to Age to Female sex to Abbreviation: SE, standard error. Table 4: Results of the Multivariate Analysis Predicting Rehabilitation LOS Characteristics SE 95% CI P FES score to BADL score to Faller to MMSE score to homes (2 short-term and 1 long-term admissions). They had lower FES scores than other participants (median 55 vs 97; Kruskall-Wallis rank-sum test, P.011). DISCUSSION This study shows that, among these older patients admitted to postacute rehabilitation, this adapted version of the FES has excellent psychometric properties, similar to the original version, in terms of internal consistency, test-retest reliability, and construct validity. In particular, results confirmed our hypotheses of significant associations with measures of function, mobility, and affect performance. This study also increases the knowledge of potential adverse effects of fear of falling and poor falls self-efficacy in the independent association with the rehabilitation LOS. To our knowledge, this is the first study that specifically addresses this issue in patients undergoing postacute rehabilitation and links poor self-efficacy at admission with an increased LOS. Although a previous study 17 in patients undergoing rehabilitation after a hip fracture mentions a correlation between change in falls self-efficacy and LOS, no multivariable analysis was performed to adjust for potential confounders. The observational design of the present study does not permit conclusions about causality, even though it is suggested by the chronology and the clear inverse dose-response relationship between falls efficacy and LOS shown in figure 2. Several hypotheses could be proposed to explain this finding. Most likely, poor falls self-efficacy might retard progress in walking rehabilitation. Measuring gait and balance performance both at baseline and before discharge could help clarify this issue. Unfortunately, this was not performed in the current study, making it impossible to adjust for gait performance to better isolate the independent effect of falls self-efficacy. This should be investigated in a future study. Similarly, poor falls efficacy might also Length of stay (days) FES score Fig 2. Relationship between FES scores (range, 0 120; higher scores indicate higher confidence) and rehabilitation LOS. interfere with rehabilitation in ADLs such as transferring, dressing, and going to the toilet. This association will also require further study. An alternative explanation could be that this association reflects poorer health and functional status in patients with poor falls efficacy. However, the relationship between the FES and LOS remained when controlling for functional, cognitive, and fall status, making it an unlikely explanation, even though residual confounding is still possible. Finally, it could also be hypothesized that an increased LOS in subjects with poor falls efficacy indirectly resulted from a difference in discharge destination because these persons were less likely to return home. However, only 5 participants did not return home. Moreover, results were similar when the analysis of LOS was repeated after excluding these subjects, as a sensitivity analysis. Disentangling this issue is certainly important because it will help in decisions as to whether interventions targeted at falls self-efficacy improvement should be added to the current panoply of interventions proposed for older patients admitted to postacute care rehabilitation. Improvements in falls efficacy have been documented in community-dwelling elderly persons using interventions ranging from simple exercise to multifaceted programs that included educational, psychologic, behavioral, environmental, and exercise components. 18,26-30 Whether similar interventions applied to older patients admitted to postacute rehabilitation will improve their functional abilities and mobility and decrease their LOS need to be further investigated. This study also confirms findings from other studies 2-4,7,9 in which falls efficacy was highly correlated with measures of functional, affective, cognitive, and mobility performance. Interestingly, falls self-efficacy was more strongly correlated with the measure of depressive symptoms than with the measure of balance and gait, a finding that contrasts with results from some studies in younger populations, 31 even though this study used a 1-item question about activity-limiting fear. Although counterintuitive, this result likely reflects the fact that psychologic characteristics are stronger determinants of FES than mobility performance in older rehabilitation patients, as found in a study that specifically investigated the affective correlates of fear of falling. 32 This is also suggested by the disappearance of the significant relationship between fall status and FES score, after controlling for depressive symptoms in the multivariable analysis. Overall, these results emphasize the complex interplay between physical and mental determinants of falls self-efficacy in older patients. Several specific comments could be added about FES use in this postacute care population. First, the addition of 2 outdoor activities (walking around the home, simple shopping) compared with the initial version of the scale proved useful to attenuate the ceiling effect observed in other, more functional populations. Nevertheless, the recently developed Falls Efficacy Scale International 33 that includes outdoor activities with higher fall risk such as walking on a slippery or on an uneven surface will certainly be more appropriate for a larger range of activity performance when assessing populations with more

5 FALLS EFFICACY IN REHABILITATION, Büla 295 heterogeneous functional and mobility status. Second, as observed in previous studies, most subjects who did not perform an activity reported difficulties in providing a rating. Prompting them by asking to estimate the extent their concern about falling played in not performing the task, as used in another study, 13 proved useful, but hypothetical rating is likely to remain an issue when using scales with standard items requiring high levels of functioning in populations with heterogeneous functional status. Finally, the use of a 0 to 10rating scale for each item also proved difficult to comprehend for some participants. A 4-level response format that was adopted in other studies 33,34 is certainly a better option. Study Limitations This study has several limitations. First, the study was conducted in a small convenience sample of subjects admitted for rehabilitation, most of whom reported 1 or more falls in the previous year. The scale might perform differently in other rehabilitation populations, especially those less directly concerned by falls experience. Second, subjects with significant depressive symptoms and those scoring lower than 20 at the MMSE were excluded. The FES performance in these subjects remains unknown but is likely to be substantially altered. Finally, we did not use a measure of comorbid conditions to adjust in the multivariable models, even though functional status likely grossly reflects health status in this population. This study also has several strengths, including the wide range of age, functional status, and mobility performance of the participants. In addition, extensive information was gathered at the baseline interview over a large set of covariates, there were no missing data on LOS, and follow-up information on discharge destination was also complete. 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