Validation of the Functioning in Chronic Illness Scale (FCIS)

Abstract

Diagnosis of deficient areas in the functioning of patient with chronic disease is necessary to undertake the adequate therapeutic actions. The aim of the study was to validate a new self-reported questionnaire for patients with chronic disease assessing the impact of the disease on the patient, the patient’s impact on the disease and the impact of the disease on patient’s attitudes. Results: The internal consistency of the questionnaire expressed by a-Cronbach coefficient = 0.855, indicates its high reliability and homogeneity. The set of 24 items fulfilled the assumption of factor analysis: the determinant of correlation matrix was 0.001, Kaiser-Mayer-Olkin (K-M-O) statistic was 0.843 and the Bartlett’ test of sphericity was statistically significant. The factor analysis was conducted using the principal component analysis with Varimax rotation. The scale and subscale levels were determined based on the percentiles scale. Conclusion: The validation procedure revealed that FCIS is a reliable and homogeneous tool to measure patient’s physical and mental functioning in the chronic illness. The set of items divided into 3 subscales allows evaluation of: the impact of the disease on the patient, the patient’s impact on the disease and the impact of the disease on the patient’s attitudes.