[Preliminary analysis of the psychometric properties of the French version of an international questionnaire measuring the quality of life: the MOS SF-36 (version 1.1)].

The International Quality of Life Assessment (IQOLA) Project is a 4 year project initiated in 1991 to translate and adapt the Medical Outcome Study Short Form 36 item Health Survey (SF-36) in at least 15 countries. This paper reports on the preliminary psychometric assessment of the SF-36 in French (version 1.1). The validation data come from two studies: a phase IV study of 121 patients with arthritis and a phase IV study of 159 patients with angina. In both cases, the patients were surveyed using the SF-36 and a disease specific module. The main objective of this analysis was to determine how well the scaling assumptions (summated rating or Likert type scaling construction) of the SF-36 were satisfied. Item convergent validity was supported as items-scale correlation range from 0.47-0.87. Item discriminant validity was supported as all items were more correlated with their hypothesised scales than with scales measuring other concepts. Our data support the assumption that the items measuring the same concept had approximately equal variance. Items in a given scale contained about the same proportion of information about the concept being measured, as most items of any given dimension had approximately the same correlation with that dimension. The Cronbach alpha coefficient ranged between 0.79 and 0.95. The correlation between two scales was less than the reliability coefficient for those scales, and these correlations adjusted for attenuation were less than 1. These preliminary results are encouraging. They indicate that the items are linearly related to the underlying concept being measured.(ABSTRACT TRUNCATED AT 250 WORDS)