CHRONIC LOW-BACK-PAIN MEASUREMENT WITH VISUAL ANALOG SCALES IN DIFFERENT SETTINGS

We asked 78 chronic low back pain patients to report on their usual pa in intensity, and on the lifestyle changes caused by their pain, on a horizontally-oriented visual analogue scale (VAS). Also, the usual and the current pain intensities were examined on a vertical VAS. Statist ical analysis showed normal distribution of data in the measurement of usual pain on the horizontal VAS, but no homogeneous distribution on the vertical VAS. Therefore, in the measurement of chronic low back pa in VAS should be used horizontally rather than vertically, because of higher sensitivity. The intensity of usual pain was significantly corr elated with the degree of lifestyle change. No correlation was found b etween current and usual pain. There was no significant difference in the failure rate between the vertical and horizontal VAS. Also, there was no reduction of the failure rate by giving additional oral explana tions in the use of the scale to the patient. Owing to a negative infl uence in distribution of rates and an increase in the failure rate, co mplex questions should be avoided. A short written introduction to the scale is sufficient, and oral explanations are not essential.