Validity and reliability of general self-efficacy scale in asthma patients

Abstract

Introduction

The General Self-Efficacy Scale (GSE) is the most commonly used screening tool for self-efficacy. Its validity has not been reported for asthma patients.

Aim

Report the validity evidence of the GSE in asthma patients.

Method

50 Greek asthma out-patients participated in the study. Self-efficacy was assessed using GSE. Construct validity was tested through differences between groups and Cross-sectional validity through correlation sof the GSE score with pulmonary function (FEV₁), asthma control (ACT), QoL (SF36v2), and Borg scale (Pearson's r correlation coefficient).

Results

Lower GSE scores were found in the following subgroups: women vs. men (p <0.01); participants with moderate vs. mild asthma (p < 0.001) or uncontrolled vs. controlled asthma (p < 0.001), and participants with hyperventilation vs. no hyperventilation (p < 0.001) or end-tidal CO₂-ETCO₂ ≤35 vs. >35 mmHg (p =0.003).Cross-sectional validity testing showed positive correlations of the GSE scorewith FEV₁ (r = 0.67, p < 0.001), ACT (r = 0.69, p < 0.001), ETCO₂ (r = 0.56, p < 0.001), PC of the SF-36 (r = 0.67, p < 0.001and MC of the SF-36 (r = 0.69, p < 0.001) as well as negative correlations with Nigmegen Questionnaire (r = -0.51, p < 0.001) and Borg scale (r = -0.54, p < 0.001). The GSE items showed high internal consistency (Cronbach alpha = 0.95) and test-retestreliability (IR = 0.96).

Conclusion.The GSE was valid and reliable in the present sample with asthma.