Life satisfaction Index: Italian version and validation of a short-form

The Life Satisfaction Index-version A (LSIA) is a 20-item questionnaire providing a cumulative score acknowledged as a valid index of quality of life. In the present study, an Italian version was produced through validated procedures of repeated back-translations. The final Italian version (LSIA.it) was administered to 90 healthy subjects (55 women; aged 40-65 yr, median 51). Cronbach alpha was 0.74, in agreement with previous studies on English, Greek, and Spanish versions, suggesting satisfactory internal consistency of the scale. Also in agreement with previous studies, factor analysis identified three factors (mood tone, zest for life, and congruence between desired and achieved goals), with eigenvalues of 2.80, 1.72, and 1.34, respectively. Nine of the original 20 items were dropped because of inconsistency with the overall scale and/or because of ambiguous loading onto the extracted factors. The resulting 11- item short form (LSI-11) had alpha = 0.69 and Kaiser-Meyer-Olkin measure of sample adequacy = 0.65. In our sample, the mean score of LSIA.it was almost the same as that previously reported in the literature for LSIA, and the correlation between LSIA and LSI-11 was very high (r = 0.91). In a test- retest trial, the cumulative score of LSI-11 showed a percentage of agreement ranging from 73.9 to 100 and Cohen's k statistic for reliability ranging from 0.51 to 1. The individual items of the LSI-11 presented substantial (k > 0.6) to excellent (k > 0.8) levels of agreement. The responsiveness of LSIA and LSI-11 during a hospital stay for 30 consecutive inpatients for medical rehabilitation programs, as measured by effect size, was 0.57 and 0.63, respectively. The results suggest that (1) the LSIA.it has cultural equivalence with the English LSIA and that (2) the 11-item short form of LSIA is not only simpler but also more valid from a psychometric standpoint.