Abstract
This study investigated whether two instruments devised for people with mental illness, the Satisfaction with Daily Occupations (SDO) instrument and the Manchester Short Assessment of Quality of Life (MANSA), showed appropriate psychometric properties in terms of internal consistency, convergent/divergent validity, and discriminant validity when used with other samples. The study group comprised two female samples, one with physical disability (scleroderma) and one reference sample without known illness. It was hypothesized that the associations from SDO would be low or moderate to both general life satisfaction and self-rated health. The results confirmed that the associations were equal in size in both samples, but still the relationship to general life satisfaction in the scleroderma sample was somewhat higher than expected. Regarding the MANSA quality of life, the hypotheses were that the quality of life index would show high correlations with general life satisfaction and moderate with self-rated health, and these hypotheses were confirmed for the reference sample, indicating that quality of life as measured by the MANSA converged with general life satisfaction but mainly diverged from self-rated health. In the scleroderma sample, the association to health was higher than expected. Both instruments appeared to reflect constructs that were stable across the two investigated groups, and both measures could distinguish the disability group from the healthy group. The SDO obtained a good value on internal consistency in the sample with scleroderma but a somewhat low value in the reference group, while the quality of life aspect of the MANSA exhibited good internal consistency in both samples. The instruments showed promising properties, indicating that they could be used for the target groups. However, both measures need further testing of psychometric properties.