Development and Psychometric Properties of the Family Support Questionnaire for Adherence to Low Fat Diet in Patients with Cardiovascular Disease

Social support is considered as a key factor in adherence to a low fat diet among patients with cardiovascular disease. The main objective of this study is to develop and evaluate the psychometric properties of the family support questionnaire for adherence to low fat diet in patients with cardiovascular disease.
The participants were 212 patients with cardiovascular disease who were discharged from 2 medical centers (Khatam Al-Anbiya and Ali Ibn Abi Talib) in the city of Zahedan. They were enrolled by the convenience sampling method. Internal consistency and Cronbach’s alpha were used to test the scale’s reliability and following, the exploratory factor analysis method (principal components analysis by using Varimax rotation) was used for the investigation factor structure.
The principal components analysis (PCA) provided support for two-factor structure (emotional and instrumental support) of the family support questionnaire for adherence to low fat diet in patients with cardiovascular disease. Two-factor structure explained 83.29% of the variance. In this analysis, the first factor (emotional support) and second factor (instrumental support), respectively, explained 63.03% and 20.25% of variance. The questionnaire had acceptable internal consistency. The Cronbach’s alpha coefficient for the questionnaire was 0.89 and for both instrumental and emotional support was equal to 0.71 and 0.99, respectively.
The present questionnaire is a valid and reliable instrument to measure family support for adherence to low fat diet in patients with cardiovascular disease.