Measuring validity of self-reported symptoms among people with HIV.

Symptoms are important indicators of health and treatment for people with HIV. Symptoms are measured by patient self-report, but there has been little attention to what is the best method of elicitation. We compared three methods (presence, frequency, and bother) commonly used to measure HIV self-reported symptoms. CD4+ T lymphocyte count and health-related quality of life (HRQL) scales were used to test validity in 160 people with HIV. The average number of symptoms reported was 15.2 (standard deviation 8.4). Correlation coefficients of summary symptom scores using the three methods ranged from -0.30 to -0.36 with HRQL score and from -0.19 to -0.20 with CD4 count (p<0.05). Correlation coefficients of seven specific symptom items with CD4+ counts and HRQL scores for the same concepts were small to moderate (-0.08 to -0.58, p<0.05). For the three methods, the correlation coefficients in general tended to be greater with frequency or bother than presence. However, the differences among the three methods were not statistically significant. We conclude that no single method is superior to the others.