Validity and reliability evidence of the general self-efficacy scale in Greek patients with COPD

Abstract

Background: Self-efficacy is associated with functional capacity and quality of life in Chronic Obstructive Pulmonary Disease (COPD) patients.

Aims and Objectives: The present study was designed to examine the validity and reliability of the General Self-Efficacy scale (GSE) responses in Greek patients with COPD.

Methods: The GSE scale (n=50) was examined for construct and criterion validity as well as internal consistency.

Results: Principal Components Analysis (PCA) revealed a two (2) factors solution (action self-efficacy and coping self-efficacy with eigen values 1.65 and 5.31 respectively) and with 69.67% total variability. Higher GSE scores were found in the following groups: a) smokers versus non-smokers (p<0.001), b) patients without visiting the emergency department versus patients with 1-2 visits in the last year (p<0.001), c) patients with regular follow-up versus patients with follow-up only in deterioration of symptoms (p<0.001), and d) among patients of the four quarters of the BODE index (F=2.89, p=0.04). Concurrent validity testing showed low to moderate high correlations for the GSE score with the 3 Minute Chair Rise Test (3CRT) (r=0.29, p<0.01) and the 6 Minute Walk Distance Test (6MWDT) (r=0.66, p<0.01), while negative correlations were found for the GSE score with age (r=-0.28, p<0.01) and the BODE index (r=-0.28, p<0.05). Further, multiple linear regression analysis showed that the 6MWDT was the predictor variable (Beta=0.72, p<0.001) of the GSE for the specific sample of COPD patients. The GSE showed high internal consistency (Cronbach' s alpha=0.89).

Conclusions: The GSE provided validity and reliability evidence for the specific Greek sample with COPD.