Life satisfaction after traumatic brain injury: comparison of ratings with the Life Satisfaction Questionnaire (LiSat-11) and the Satisfaction With Life Scale (SWLS)

BACKGROUND An optimal life satisfaction (LS) is considered an important long-term outcome after a traumatic brain injury (TBI). It is, however, not clear to what extent a single instrument captures all aspects of LS, and different instruments may be needed to comprehensively describe LS. The aim of this study was to compare self-ratings of life satisfaction after a TBI with two commonly used instruments. METHODS Life Satisfaction Questionnaire (LiSat-11), comprising eleven items and Satisfaction With Life Scale (SWLS), comprising five items, were administered to 67 individuals (51 men and 16 women). Secondary analysis of data collected as part of a survey of individuals with TBI 6 to 15 years post TBI. RESULTS Item 1 in LiSat-11 ('Life as a whole') and the total SWLS score was strongly correlated (Spearman's rho = 0.66; p < 0.001). The total score in SWLS had the strongest correlation with items in LiSat-11. All items in LiSat-11, except 'Family life' and 'Partner relationship', were moderately to strongly correlated with items in SWLS. The item 'Partner relationship' in LiSat-11 did not correlate with any of the items in SWLS or the total score. The item 'If I could live my life over, I would change nothing' in SWLS had the weakest correlations with items in LiSat-11. Items 'Vocation' and 'Leisure' in LISat-11 were most strongly correlated with items in SWLS, whereas the item 'ADL' in LiSat-11 was more weakly correlated with items in SWLS. CONCLUSIONS The strength of the relationships implies that the two instruments assess similar but not identical aspects of LS and therefore complement each other when it is rated.