Short Form 36 in the intensive care unit: assessment of acceptability, reliability and validity of the questionnaire

Abstract

The aim of this study was to assess the acceptability, validity and reliability of the Short Form 36 quality of life questionnaire in 166 adult patients following discharge from a general intensive care unit. Reliability was quantified by measuring internal consistency using correlation among items and Cronbach's alpha coefficient. Reliability coefficients were calculated from two-way analysis of variance. Construct validity was tested by examining differences in scores between sex and age groups. Content validity was reflected by the spread of dimension scores. Acceptability to patients appeared reasonable, although considerable nursing time was required to administer the questionnaire. The measures of reliability exceeded recognised statistical standards in all but two instances. Construct validity was confirmed by lower scores being reported by women and older age groups. The scores of six of the eight dimensions were spread throughout the entire range of possible scores suggesting acceptable content validity.