THE CORRELATION BETWEEN THE FIBROMYALGIA IMPACT QUESTIONNAIRE AND THE HEALTH STATUS QUESTIONNAIRE: IMPLICATIONS FOR USE IN PAIN STUDIES

In recent years, there has been increased attention to quantifying psychosocial variables associated with fibromyalgia and other pain populations. It is widely recognized that patient perception of functioning has a great influence on overall adaptation to chronic pain and motivation for rehabilitation. Two psychometric scales have been used for this purpose, the Fibromyalgia Impact Questionnaire (FIQ) and the Health Status Questionnaire (HSQ). The FIQ was developed as a specific measure of the impact of fibromyalgia has across several domains. These include specific physical symptoms, physical functioning, ability to work and perform activities of daily living, and emotional functioning. The FIQ has good psychometric properties and has been well validated in a number of studies. By its nature however, its use is confined to this specific pain population. The HSQ has been designed to be a measure of perceived health and functioning in a more general medical population. In our experience with both of these measures it seemed that there would be significant overlap in the measured constructs. This study compared the subscales of the FIQ with the Physical Functioning Subscale and the Mental Health Subscale from the HSQ. All comparisons using a Pearson Correlation were significant at p < 0.001. These results indicate a high degree of overlap between these two measures. This overlap further confirms the construct validity of the FIQ. Further, since these two measures appear closely related, the use of the HSQ in other pain populations could be considered a valid measure of functioning and perceived health status. Both of these measures have adequate reliability and show changes when used as treatment outcome variables.