Measuring change over time: a comparison of results from a global single item of health status and the multi-dimensional SF-36 health status survey questionnaire in patients presenting with menorrhagia

Abstract

This paper compares the sensitivity to change of a multi-item, multi-dimensional health status measure with a single global health status question, in the assessment of treatment for menorrhagia. A cohort study of patients recruited by general practitioners, was carried out, with a follow up at eighteen months. Questionnaires were administered postally at base-line and follow up. General practices in Berkshire, Buckinghamshire, Northamptonshire and Oxfordshire supplied three hundred and nine women who reported heavy menstrual bleeding, and received either drug treatment alone or both drug and surgical treatment (endometrial resection or hysterectomy) during the eighteen months between the two administrations of the questionnaires. A single global question was given to patients asking them to rate their overall health status as 'excellent', 'very good', 'good', 'fair' or 'poor'. The eight dimensions of the SF-36 health survey questionnaire were also given to patients to complete. The dimensions of the SF-36 indicated only small levels of improvement for patients who received drug treatment. However, on many dimensions of the SF-36, a moderate to large improvement was detected for the surgical group. However, small changes were reported in overall health status, as indicated by the single global question, for both groups. Single item measures of health status may not provide a sufficiently accurate indication of health status to be appropriate for use in longitudinal studies.