Validity of the life satisfaction questions, the life satisfaction questionnaire, and the satisfaction with life scale in persons with spinal cord injury

Post MW, van Leeuwen CM, van Koppenhagen CF, de Groot S. Validity of the Life Satisfaction questions, the Life Satisfaction Questionnaire, and the Satisfaction With Life Scale in persons with spinal cord injury. Objective: To assess and compare the validity of 3 life satisfaction instruments in persons with spinal cord injury (SCI). Design: Cross-sectional study 5 years after discharge from inpatient rehabilitation. Setting: Eight rehabilitation centers with specialized SCI units. Participants: Persons (N=225) with recently acquired SCI between 18 and 65 years of age were included in a cohort study. Data were available for 145 persons 5 years after discharge. Interventions: Not applicable. Main Outcome Measures: The Life Satisfaction questions (LS Questions), the Life Satisfaction Questionnaire (LiSat-9), and the Satisfaction With Life Scale (SWLS). Results: There were no floor or ceiling effects. Cronbach α was questionable for the LS Questions (.60), satisfactory for the LiSat-9 (.75), and good for the SWLS (.83). Concurrent validity was shown by strong and significant Spearman correlations (.59-.60) between all 3 life satisfaction instruments. Correlations with measures of mental health and participation were.52 to.56 for the LS Questions,.45 to.52 for the LiSat-9, and.41 to.48 for the SWLS. Divergent validity was shown by weak and in part nonsignificant correlations between the 3 life satisfaction measures and measures of functional independence and lesion characteristics. Conclusions: Overall, the validity of all 3 life satisfaction measures was supported. Despite questionable internal consistency, the concurrent and divergent validity of the LS Questions was at least as good as the validity of the LiSat-9 and the SWLS.