Objective: We intended to determine the reliability of a brief life satisfaction scale in a sample of patients with chronic diseases, and to analyze its external validity.
Methods: Reliability and factor analysis of the 8-item "Brief Multidimensional Life Satisfaction Scale" (BMLSS) were performed according to standard procedures. The test sample contained 979 individuals (mean age 54+/-11 years). Forty-two percent had cancer, 22% chronic pain conditions, 10% depressive disorders, 6% other chronic diseases, and 20% were healthy.
Results: Reliability analysis of the 8-item pool revealed a good internal consistency coefficient (Cronbach's alpha=.869), and a single-factor structure which explains 53% of variance. The BMLSS sum scores significantly differed with respect to the underlying disease, family status, duration of disease, and age. The highest scores were found in healthy individuals, and the lowest in patients with chronic pain conditions and depressive disorders. In cancer patients, the BMLSS correlated negatively with Depression/Anxiety (HADS), Fatigue (CFS-D), and positively with SF-12's mental health and to a weaker content also with physical health. Stepwise regression analyses revealed that life satisfaction can be predicted best by (the absence of) depression, but also by Conscious Living (AKU), which is an active cognitive-behavioral style in terms of adaptive coping.
Conclusions: The evaluation of the BMLSS revealed that the instrument has good psychometric properties and can be regarded as a brief, reliable and valid measure of LS in patients with chronic diseases. The instrument can be an important additive to existing health-related quality of life questionnaires, since it captures dimensions that contribute to quality of life but are not health related.