Quality of life of caregivers of breast cancer patients: a cross-sectional evaluation
Authors: Clarijs Marloes E. , Oemrawsingh Arvind , Bröker Mirelle E. E. , Verhoef Cornelis , Lingsma Hester , Koppert Linetta B. 
Published: February 2022

Abstract
Background
The aim of this study was to evaluate the care-related quality of life in caregivers of breast cancer patients, to assess its association with breast cancer patients’ health-related quality of life (HRQoL), and to identify its potential predictors.

Methods
Caregivers of breast cancer patients at six and twelve months follow up were identified through the institutes electronic patient reported outcome measurement collection tool. The Care-related Quality of Life Instrument (CarerQoL) was used to obtain CarerQoL utility scores by applying a pre-existent set of Dutch tariffs and the CarerQoL VAS score, which represented the overall happiness of caregivers. The associations between breast cancer patients’ EQ-5D-5L and EORTC QLQ-C30 scores and caregivers’ CarerQoL scores was determined with Spearman’s correlation coefficients. Associations between log transformed CarerQol scores and patient and caregiver characteristics were analyzed with multivariable linear regression analyses.

Results
A total of 116 completed CarerQoL questionnaires were analyzed. Most caregivers were male spouses or partners (81.4%) with a mean age of 55.7 ± 16.4. The median CarerQoL utility score was 92.4/100 and median CarerQoL VAS was 8.0/10. We found weak correlations between CarerQoL VAS scores and patients’ EQ-5D-5L utility score (0.301, p = 0.002) and EQ VAS score (0.251, p = 0.009), and between EORTC QLQ-C30 scores and CarerQol VAS (0.339, p < 0.001) and utility score (0.236, p = 0.015). There was a negative association between chemotherapy and log-transformed CarerQoL utility score (B =  − 0.063, p = 0.001) and VAS score (B =  − 0.044, p = 0.038) at six months follow-up.

Conclusions
This study provides the first evaluation of the CarerQoL in caregivers of Dutch breast cancer patients. Caregivers’ happiness was associated with breast cancer patients’ HRQoL. Our results can be used as reference values for future care-related quality of life evaluations.

Plain English Summary
Breast cancer patients face many difficulties during their cancer journey and often need the support of their caregivers. Despite the fact that successfully providing informal care can have positive effects on caregivers’ wellbeing, it may also have a negative impact on their quality of life. Monitoring the quality of life using a standardized questionnaire, such as the CarerQoL questionnaire, may result in early detection of possible quality of life issues. In this study, we evaluated 116 caregivers and found overall high CarerQoL scores. The scores showed a positive relation to the patients’ quality of life. Lower CarerQoL scores at six months after surgery were found in caregivers of patients who received chemotherapy. Our research underlines the importance to include caregivers of breast cancer patients in clinical practice, provides reference values for future research, and the results can be used to manage the caregivers’ expectations prior to treatment.