Reliability and Validity of Turkish Version of the Caregiver Quality of Life Index Cancer Scale

Background: Measuring effects of cancer on family caregivers is important to develop methods which canimprove their quality of life (QOL) . Nevertheless, up to now, only a few tools have been developed to be usedin this group. Among those, the Caregiver Quality of Life Index-Cancer Scale (CQOLC) has met minimumpsychometric criteria in different populations in spite of conflicting results. The present study was conducted toevaluate reliability and validity of CQOLC among Turkish cancer family caregivers. Materials and
Methods:The CQOLC was administered to 120 caregivers, along with Beck Depression Inventory (BDI), MedicalOutcomes Study MOS 36- Item Short Form Health Survey (SF-36), State–Trait Anxiety Inventory (STAI), andMultidimensional Scale of Perceived Social Support (MSPSS). Internal consistency and test-retest stability wereused to investigate reliability. Construct validity was examined by using known group method, convergent, anddivergent validity. For the known group method, we hypothesized that CQOLC scores would differ betweendepressed and non-depressed subjects. We investigated convergent validity by correlating scores for CQOLCwith scores for other similar measures including SF-36 and STAI. The MSPSS was completed at the same timeas CQOLC to provide divergent validity.
Results: The values for internal consistency and test-retest correlationwere 0.88 and 0.96, respectively. The CQOLC discriminated those who were depressed from those who werenot. Convergent validity supported strong correlations between CQOLC scores and two main component scores(PCS, MCS) in SF-36 although there was a weak correlation between CQOLC and STAI scores. Regardingdivergent validity, the correlation between CQOLC and MSPSS was in the low range, as expected.
Conclusions:The Turkish CQOLC is a reliable and valid tool and it can be utilized to determine QOL of family caregivers.