Validity of the Life Satisfaction questions, the Life Satisfaction Questionnaire, and the Satisfaction With Life Scale in persons with spinal cord injury

Abstract

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.