The Falls Efficacy Scale International is a valid measure to assess the concern about falling and its changes induced by treatments

Abstract

Objective To test with the Rasch analysis the psychometric properties of the Falls Efficacy Scale International, a questionnaire for measuring concern about falling. Design Longitudinal observational study, before–after rehabilitation. Setting Inpatient rehabilitation. Subjects A total of 251 neurological patients with balance impairment. Interventions Physiotherapy and occupational therapy aimed at reducing the risk of falling. Main measures Participants (median age, first–third quartile: 74.0, 65.5–80.5 years; stroke and polyneuropathy: 43% and 21% of the sample, respectively) received a balance assessment (Falls Efficacy Scale International included) pre- and post-rehabilitation. Rasch analysis was used to evaluate the Falls Efficacy Scale International. Differential item functioning, which assesses the measures’ stability in different conditions (e.g. before vs. after treatment) and in different groups of individuals, was tested for several variables. Results Patients suffered a moderate balance impairment (Mini-BESTest median score; first–third quartile: 15; 11–19), mild–moderate concern about falling (Falls Efficacy Scale International: 28; 21–37) and motor disability (Functional Independence Measure, motor domain: 70.0; 57.0–76.5). Falls Efficacy Scale International items fitted the Rasch model (range of infit and outfit mean square statistics: 0.8–1.32 and 0.71–1.45, respectively) and the questionnaire's reliability was satisfactory (0.87). No differential item functioning was found for treatment, gender, age and balance impairment. Differential item functioning was found for diagnosis and disability severity, but it is shown that it is not such as to bias measures. Conclusions Falls Efficacy Scale International ordinal scores can be turned into interval measures, i.e. measures of the type of temperature. Being differential item functioning-free for treatment, these measures can be safely used to compare concern about falling before and after rehabilitation, such as when interested in assessing the rehabilitation effectiveness.

Berg Balance Scale is a Valid Measure for Plan Interventions and for Assessing Changes in Postural Balance in Patients with Stroke

“…In particular, the finding of no DIF for the intervention means that the BBS can be used safely to compare an individual's postural balance before and after interventions, thus increasing the chance of drawing the correct conclusions about the effectiveness of interventions. A similar recent analysis of the Falls Efficacy Scale -International suggested that there were no items of DIF before and after rehabilitation (30). There is growing evidence that scales validated by Rasch analysis are more valid than scores validated by classical test theory (31,32).…”

Differential Item Functioning of the Mini-BESTest Balance Measure: A Rasch Analysis Study

“…Patient-reported outcome measures of gait and balance constructs are available (e.g., the Falls Efficacy Scale International for measuring concern about falling [ 31 ]). Interestingly, these measures can have better psychometric features, such as higher responsiveness (e.g., [ 73 ]), than clinician-administered tests.…”

“…The theoretical underpinnings of the Rasch analysis can be found in [ 17 , 18 , 19 ], while the technical details of the analysis run here can be found in [ 31 , 36 , 37 ]. Briefly, the Rasch analysis assesses whether the scores of questionnaire items comply with the Rasch measurement requirements of (i) ordered item categories, (ii) fit of data to the model of Rasch, (iii) unidimensionality, and (iv) absence of DIF.…”

“…Patients scoring < 35 (out of 35) on the cognitive domain of the FIM scale were considered cognitively impaired. Conversely, entirely in line with the FIM scale instructions, patients scoring 35/35 were supposed to suffer no cognitive impairment [ 31 ]. Persons scoring 35/35, i.e., scoring 7/7 in the five cognitive items, have no communication impairment, memory problem, or difficulty in problem-solving or social interaction.…”

“…Crucial in medicine is also verifying the invariance of the items functioning for the passing of time [ 30 ]. Most importantly, when a questionnaire or a scale is used as an outcome measure, the absence of DIF for treatment must be evaluated [ 31 ]. Showing the items’ stability before and after treatments increases confidence in drawing conclusions about treatment efficacy.…”