Reliability and validity of the Falls Efficacy Scale-International after hip fracture in patients aged ≥ 65 years

Purpose: To assess the measurement properties of the Falls Efficacy Scale-International (FES-I) in patients after a hip fracture aged ≥ 65 years.

Methods: In a sample of 100 patients, we examined the structural validity, internal consistency and construct validity. For the structural validity a confirmatory factor analysis was carried out. For construct validity predetermined hypotheses were tested. In a second sample of 21 older patients the inter-rater reliability was evaluated.

Results: The factor analysis yielded strong evidence that the FES-I is uni-dimensional in patients with a hip fracture; the Cronbach's alpha was 0.94. When testing the reliability, the intra-class correlation coefficient was 0.72, while the Standard Error of Measurement was 6.4 and the Smallest Detectable Change was 17.7 (on a scale from 16 to 64). The Spearman correlation of the FES-I with the one-item fear of falling instrument was high (r = 0.68). The correlation was moderate with instruments measuring functional performance constructs and low with instruments measuring psychological constructs.

Conclusions: Reliability and structural validity of the FES-I in patients after a hip fracture are good. The construct validity appears more closely related to functional performance constructs than to psychological constructs, suggesting that the concept measured by the FES-I may not capture all aspects of fear of falling.

Implications for rehabilitation: The Falls Efficacy Scale-International (FES-I), which is commonly used to measure fear of falling in community-dwelling older persons, can also be used to assess fear of falling in patients after a hip fracture. The reliability and the structural validity of the FES-I for these hip patients are good, whereas the construct validity of the FES-I is not optimal. The FES-I may not capture all aspects of fear of falling and may be more closely related to functional performance than to psychological concepts such as anxiety.