Measure of disease impact: instrument construct validity in patients with coronary artery disease

This study estimated the known groups construct validity for the Instrument to Measure the Impact of Coronary Disease on Patient's Everyday Life (IDCV) related to signs and symptoms, ventricular systolic function, left ventricular ejection fraction (LVEF) and health-related quality of life (HRQoL) in 153 outpatients with coronary artery disease. Data was obtained through application of IDCV and Brazilian versions of the instruments The Medical Study 36-item Short Form Health Survey - SF-36 and the MacNew Heart Disease Health-related Quality of Life Questionnaire. Mann-Whitney test was used to verify the ability of IDCV in discriminating impact of signs and symptoms, LVEF and ventricular systolic dysfunction. Also, the Kruskal-Wallis test was used to verify the discrimination power of the IDCV in relation to HRQoL. It was observed that the IDCV discriminated the impact between variables scored in HRQOL quartiles (<= Q1, Q1-Q3, >= Q3). The study findings contribute for improvement of IDCV in measurement of disease impact in coronary artery disease patients.