Issues associated with measuring symptom status: HIV/AIDS case illustration.

The purpose of this article is to illustrate issues associated with measuring one aspect of health, symptom status, through a comparison of two specific symptom scales developed for use with persons with HIV/AIDS. A number of decisions are necessary to evaluate the appropriateness of different health measurement instruments. These include: whether the purpose is to evaluate a program of care or to study individual patients; characteristics that are being assessed; the time frame being assessed; how broad-ranging an assessment is desired; and the scope of detail that is desired. This descriptive survey with a HIV+ sample (N = 100) found that there were 8 items that assessed identical symptoms on the Sign and Symptom Checklist-HIV and the HIV Assessment Tool. There were no significant correlations between similar items on the two instruments. There were significant differences between the mean scores only for headaches (t = -3.4, p = .001). Issues related to symptom appraisal, the time frame, and the nature of symptom-related variables need to be carefully considered before choosing a measurement instrument.