Measurement of pain: patient preference does not confound pain measurement.

Chronic pain patients reported pain intensity on each of 3 pain intensity scales, the visual analog, numerical and adjectival scales, and then ranked the scales in order of perceived best communication of pain intensity. All patients were able to complete an adjectival scale but 11% were unable to complete a visual analog scale and 2% failed at a numeric scale. The intensity of the pain ratings on the 3 scales were significantly correlated and there were no reliable differences in reported intensity as a function of preference. Pain intensity was reliably higher on each scale for depressed-anxious patients as compared to non-depressed/non-anxious patients. Patients completing all 3 scales indicated a significant preference for the adjectival scale but the basis for this preference did not appear related to sex, etiology of pain, affective variables nor selected psychological variables. These data indicate that pain scale preference does not influence pain intensity report. Nevertheless, there are some clinical situations in which a numeric scale is likely to yield a better measure of pain intensity.