Validity and reliability of the SF-36 Health Survey Questionnaire in patients with coronary artery disease

The validity and reliability of the SF-36 has been studied in 185 patients hospitalized with suspected ischemic cardiopathy, classified into four grou ps (AMI, unstable angina, nonischemic cardiologies, and absence of cardiolo gies). The validity of the construct has been analyzed by means of the asso ciation of the SF-36 with sociodemographic and clinical variables, and with diagnostic groups. The correlation of the subscales with GHQ-28 scores and the factorial structure have been studied. Internal consistency was measur ed by Cronbach's alpha and the item-internal consistency and item-discrimin ant validity. The validation result was as expected, although the scores we re significantly lower in patients with unstable angina, only in the PF, VT , and GH subscales. The: correlations with the GHQ-28 were high for MH and VT. The internal consistency was high (Cronbach's alpha 0.72-0.94). Factori al analysis identified eight factors, with the "anxiety" component of subsc ale MH remaining as an independent factor. These results suggest that the S F-36 is a useful scale for the differentiated clinical forms of ischemic ca rdiopathy, with the additional capability of reflecting the level of anxiet y in these patients. (C) 2000 Elsevier Science Inc. All rights reserved.