OBJECTIVES: To evaluate the measurement properties of the 15-item version of Singapore Caregiver Quality of Life Scale (SCQOLS-15) in caregivers of patients with heart diseases.

METHODS: Family caregivers of patients with chronic heart diseases in Singapore self-administered SCQOLS-15 at baseline and 1 week later. Convergent validity of SCQOLS-15 and its subscales (physical well-being [PW], mental well-being [MW], experience & meaning [EM], impact on daily living [DL], financial well-being [FW]) was assessed in terms of Spearman correlation coefficient (r) with Instrumental Activity of Daily Living (IADL) score, Brief Assessment Scale for Caregivers (BASC) and its subscales, and Finance subscale of Caregiver Reaction Assessment (CRA). Know-group validity was assessed using the New York Heart Association (NYHA) performance class. Internal consistency and test-retest reliability were assessed using Cronbach’s alpha (α) and intraclass correlation coefficient (ICC), respectively.

RESULTS: Of the 327 caregivers (mean age 49 years, 68% women) included, 65% were adult children and 28% spouse. The distribution of NYHA classes of the patients was I: 27%, II: 40%, III: 24%, and IV: 9%. PW and DL were positively correlated with IADL score (each r≥0.3); SCQOLS-15 total and MW scores were positively correlated with BASC Negative Personal Impact and total scales (each r≥0.5); EM was positively correlated with BASC Positive Personal Impact (r=0.4); FW was negatively correlated with CRA Finance subscale (r=-0.6). The mean values of SCQOLS-15 and all its subscales were lower among caregivers who were caring for patients with NYHA class III/IV compared to class I/II (each P<0.05). α for SCQOLS-15 and all subscales were ≥0.8, except 0.78 for MW. Among 150 caregivers who completed the follow-up and self-rated a stable quality-of-life, ICCs for test-retest reliability for SCQOLS-15 and all subscales were ≥0.8.

CONCLUSIONS: SCQOLS-15 is valid and reliable for measuring the quality of life in caregivers of patients with heart diseases.