Psychometric Properties of Turkish Version of Survey of Activities and Fear of Falling in the Elderly Among Patients with Parkinson's Disease

Objective: Fear of falling (FOF) is one of the important risk factors for falling, is higher in patients with Parkinson's disease (PD). The Survey of Activities and Fear of Falling in the Elderly (SAFFE) differs from other scales in terms of considering the accompanying activity limitation. The aim of the study was to show the psychometric properties of the Turkish version of SAFFE (SAFFE-T) in PD, and to correlate SAFFE FOF subscale scores with age, disease duration, and the Turkish version of Movement Disorder Society Unified Parkinson's Disease Rating Scale-III (MDS-UPDRS-TR-III) motor score. Materials and Methods: A total of 93 patients with PD were evaluated. Seventy patients who met the inclusion criteria were included. Responders received a second survey after about 5 to 7 days. The internal consistency was examined by means of Cronbach's alpha. The construct validity was evaluated using the Falls Efficacy Scale International (FES-I) and with Spearman's rest. The test-retest reliability was studied in terms of intraclass correlation coefficient (ICC21), the standard error of measurement (SEM), and the minimal detectable difference (MDC95). The correlation between SAFFE FOF subscale scores and age, duration of disease, and MDS-UPDRS-TR-III score was evaluated using Spearman's test. Results: The mean age of the patients was 60.99 (range: 33-84), mean duration of the disease was 7.27 years (range: 1-22), and mean MDS-UPDRS-TR-III score was 28.40 (range: 6-69). The test had excellent internal consistency (alpha: 0.854) and test-retest reliability (ICC21:0.98/SEM: 0.36/MDC95: 1.00 for activity levels, ICC21: 0.86/SEM: 0.22/MDC95: 0.61 for FOF, ICC21: 0.99/SEM: 0.36/MDC95: 1.00 for activity restriction subscales). All subscales were moderately correlated with the FES-I (r(s)=0.51, p<0.001; r(s)=0.59, p <0.001; r(s)=0.56, p<0.001, respectively). The SAFFE-FOF subscale score was correlated with MDS-UPDRS-TR-III score (r(s)=0.31, p=0 009), but it was not correlated with age and duration of disease (r(s)=0.22, p=0.85; r(s)=0.11, p=0.38, respectively). Conclusion: The SAFFE-T, which has excellent internal consistency and reliability, appears to be an appropriate survey for measuring FOF in PD and correlates with disease severity.