Frequent measurement of chronic pain: an electronic diary and empirical findings

The PIPER (Prompting Intensity of Pain Electronic Recorder) is a compact data-logging device, easily worn by a subject. It emits audible beeps at pre-programmed times, prompting the subject to enter a pain rating by button press. Ratings are stored, for later down-loading. We report two studies suggesting that PIPER pain ratings have good reliability, and good validity assessed against the VAS. In a third study, the PIPER was found practical for use by elderly subjects, and for periods of more than 2 months. In addition, PIPER pain ratings taken 4 times per day were found to have different properties than 4 other measures of chronic pain, suggesting that very frequent measures should be taken if a full understanding of chronic pain is to be obtained.