Psychometric Properties of the Spanish Version of the Fatigue Assessment Scale in Caregivers of Palliative Care Patients.

Symptoms of fatigue and lack of energy are very common in caregivers of palliative care (PC) patients, traditionally associated with variables such as burden or depression. There are no Spanish-language instruments validated for assessing fatigue levels in this population. The Fatigue Assessment Scale (FAS) is a useful and simple instrument for assessing fatigue in this group. The aim of this study was to examine its psychometric properties (factor structure, reliability and validity) in a sample of caregivers of PC patients. Instrumental design for instrument validation was performed. One hundred and eight caregivers of PC patients participated and completed measures of fatigue, family functioning, life satisfaction, caregiver burden, anxiety, depression, resilience and quality of life. A confirmatory factor analysis was performed; non-linear reliability coefficient and Pearson correlations and t-tests were conducted to assess evidence of reliability and validity. The Spanish version of the FAS was found to have a one-dimensional structure. Reliability was 0.88. Validity evidence showed that FAS scores were positively associated with levels of burden, anxiety and depression. They were negatively associated with family functioning, life satisfaction, resilience and quality of life. The Spanish version of the FAS in caregivers of PC patients shows adequate psychometric properties.