CHANGES IN THE SF-36 IN 12 MONTHS IN A CLINICAL-SAMPLE OF DISADVANTAGED OLDER ADULTS

OBJECTIVES. The present study assessed changes in the Medical Outcomes Study 36-item short-form health survey (SF-36) during a Ill-month per iod and examined the relation of those changes to selected baseline ch aracteristics. METHODS. The study was a IF-month follow-up evaluation of 786 disadvantaged adults aged 50 to 99 years old who had participat ed in a randomized controlled clinical trial in the general medicine o utpatient clinics of a major academic medical center. Descriptive and psychometric analyses of changes in the SF-36 scale scores during a 12 -month period were performed, and two series of multivariable logistic regressions of increases or decreases greater than one standard error of measurement (SEM) versus stability on selected baseline characteri stics were done. Measures were the eight SF-36 scales. RESULTS. Mean b aseline scores on the SF-36 scales were substantially below age-specif ic national norms. Problematic floor and/or ceiling effects were found for the bodily pain, social function, role-physical, and role-emotion al scales, consistent with age-specific national norms. Internal consi stency was unacceptable for the general health perceptions scale, adeq uate for the social function scale, and good for all the other SF-36 s cales. Improvements greater than one standard error of measurement wer e found for between one fifth and one third of the patients, and decli nes greater than one standard error of measurement were found for betw een one fifth and one third of the patients. Selected baseline charact eristics generally were unrelated to either improvements or declines o n the SF-36 scales. CONCLUSIONS. The SF-36 scales appear to be suffici ently sensitive for measuring changes in health outcomes during a I-ye ar period in older patients with debilitating disease. Little of the m easured change, however, was predictable.