Measurement Properties of the 15-Item Singapore Caregiver Quality of Life Scale (SCQOLS-15) in Family Caregivers of Patients with Heart Diseases

Purpose To evaluate the measurement properties of the 15-item Singapore Caregiver Quality of Life Scale (SCQOLS-15) in family caregivers of patients with heart diseases. Methods The SCQOLS-15 survey was self-administered by family caregivers of patients with chronic heart diseases, at baseline and 1 week later. The criterion validity of SCQOLS-15 and its domain scores was assessed by calculating the Spearman correlation coefficient (ρ) with the Brief Assessment Scale for Caregivers (BASC), Caregiver Reaction Assessment (CRA), and their sub-scores. Known-group validity was assessed using the New York Heart Association (NYHA) functional class. Test-retest reliability was evaluated using the intraclass correlation coefficient (ICC). Results Of the 327 caregivers included, 65% were adult children and 28% were spouses. The distribution of NYHA classes of the patients was I: 27%, II: 40%, III: 24%, and IV: 9%. There was a positive correlation between the SCQOLS-15 and BASC total scores (ρ = 0.7). SCQOLS-15 domain scores were also correlated with BASC and CRA sub-scores as per a priori hypotheses, with absolute values of ρ ranging from 0.4 to 0.6. The mean values of SCQOLS-15 total and all domain scores were lower among caregivers of patients with NYHA class III/IV compared to those of class I/II patients (each P